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Anti-Submarine Warfare Aircraft; 188 built, 160 upgraded to S-3B
An S-3 Viking comes in to land on the aircraft carrier USS Independence. [National Archives]The Lockheed S-3 Viking was an anti-submarine warfare aircraft designed to replace the aging S-2 Tracker, later becoming one of the most important components of the US Navy’s anti-submarine strategy during the late Cold War. Designed in anticipation of modern Soviet Nuclear submarines, the Viking could boast of a host of cutting edge sensors and computerization that put it well above the curve, and all wrapped up in an airframe that was reliable and versatile. Its exceptional anti-submarine capabilities were augmented even further during its mid-life improvements which lead to the introduction of the improved S-3B. After the Cold War, the aircraft transitioned away from its traditional anti-submarine duties to surface surveillance, signals intelligence, and aerial tanker duties. A thoroughly reliable and advanced aircraft, the Viking easily ranked among the most important and versatile aircraft to ever serve aboard US carriers.
The Modern Submarine
The submarine of the Second World War was little more than a long range torpedo boat with the ability to submerge itself for short periods of time to avoid detection. Its offensive capabilities were rather modest, and apart from some outlying, but considerable, success against warships, it was typically seen as a tool for disrupting overseas shipping. Their comparatively low speed coupled with the need to transit on the surface for long periods, which snorkels could not entirely eliminate, would see them become a supporting vessel of most navies. However, advancements near the end of the war would transform the submarine from a raider and reconnaissance vessel, to one of naval warfare’s principal combatants.
Owing to the extreme desperation of the German U-boat force, a submarine built along new, revolutionary lines was designed. As the surface proved an exceptionally dangerous place to be, due to long range Allied patrol aircraft, the new boat would be designed to operate almost entirely submerged for the duration of its patrols. The new Type XXI was designed around the most modern features of any submarine thus built, featuring a much improved pressure hull construction, partially-automatic torpedo loading, a powerful sonar array, and a massive battery capacity which, combined with a hydrodynamically clean hull, allowed it to travel at double the speed of a conventional Type VIIC with over three times the range.
A Type XXI submarine ready to be assembled from prefabricated sections. Massive quality control problems prevented any hope of the submarine’s use in the Second World War, though this construction process was improved post-war world wide. [national archives]The Type XXI only completed a single wartime patrol, but its effects on naval engineering and submarine design were dramatic. In effect, every submarine built before it was obsolete, effectively restarting a new naval arms race. In the context of the then brewing Cold War, this was the cause of no shortage of anxiety for Western Navies. While the Soviet Union’s shipbuilding capabilities were relatively meager, and greatly damaged during the war, their experience with the new German submarine could very well allow them to leap up to the position of the world’s most prominent navies, if only in the field of submarine design.
In addition to the new submarine’s capabilities, the Type XXI also demonstrated that submarines could also be built at an unheard of rate thanks to its modular construction. Submarine sections could be constructed at secondary factories before being shipped to main construction yards, where they would be assembled into completed boats. Initially, an intelligence survey estimated that the Soviet Union could have as many as 2000 modern diesel-electric submarines in 1960. However, a much more reasonable secondary survey noted that they were likely restricted to 400 boats, owing to available dockyard space, fuel, and bottlenecks in battery maintenance and production. Regardless, the US Navy began work on a modernized anti-submarine strategy to counter a potential flood of Soviet boats which could threaten intercontinental supply lines in a potential war.
The first Whiskey class submarines were only marginal improvements on their WWII era predecessors. Late models, pictured here, had snorkels and performance somewhat below the German Type XXI, but with hundreds made in a relatively short time, their numbers helped offset these deficiencies. [US Navy]The first of the new Soviet boats was the Project 613 ‘Whiskey’, a somewhat shrunken derivative of the German Type XXI. It had more modest performance than the German boat in regards to speed, range, and endurance, but once it received a snorkel on later models, it had the same ability to remain underwater for long periods. The Whiskey was thus the most advanced submarine the Soviet Union had yet built. In countering these submarines, the US Navy would employ a modified version of the same strategy it had used in the Second World War. The primary anti-submarine weapon was to remain the airplane, in the form of long range patrol aircraft, like the P-2 Neptune, and carrier based planes, like the new models of TBM-3 Avenger. Their primary means of locating submarines were radar, which could detect snorkeling submarines, magnetic anomaly detectors, which were set off by a submarine’s magnetic signature, and sonobuoys, which determine the position of a transiting submarine if dropped close enough. Radar was the main means of detecting a submarine at range, with the other two systems being used to ‘fix’ its location before attacking with torpedoes and depth charges.
Unlike their land based counterparts, early carrier based ASW aircraft lacked the ability to carry both the sensors and weapons needed for the task and were thus placed in a pair of cooperating aircraft. The first such pair were the TBM-3W ‘warning’, for detection, and TBM-3S ‘strike’, for carrying out attacks on marked submarines. These hunter-killer teams operated aboard modified escort carriers and later switched to fleet carriers, when it became clear the small escort carriers could not reliably launch and recover the larger hunter-killers. In the early 50s, it was recognized that the entire system was extremely clumsy and would not provide adequate anti-submarine support.
The Hunter-Seeker ASW method proved far too unwieldy for further use. This ‘hunter’ Grumman Guardian has a search radar on one wing and a high powered searchlight under the other. Its torpedo was stored internally. These were the largest single engine piston aircraft in service at the time of their introduction. (US navy)
The CVS program was thus introduced, which brought several mothballed WWII era-fleet carriers back into service as dedicated anti-submarine warfare ships. The CVS’s, which were introduced in 1952, were soon joined by the S-2 Tracker two years after. The Tracker was large enough to carry both the sensors and the weapons, and the clumsy hunter-killers were finally dispensed with. The S-2 was an excellent ASW aircraft which would go on to serve in a number of roles, though by the mid 60s, the growing capabilities of Soviet submarines and operational troubles with operating a piston engined aircraft on increasingly jet dominated carriers began to highlight the need for a replacement.
The Soviet Nuclear Submarine
Through the 50s and early sixties, the existing strategies for sub hunting were predicated on the need for submarines to recharge their batteries, and that said batteries could be discharged during a drawn out search, thus rendering the submarine helpless. Advancements in Soviet nuclear engineering would end up negating most of these existing strategies. General Secretary Iosif Stalin would formally sign off on the program to build the first Soviet nuclear submarine in 1952. The boat was to be a delivery platform for a gigantic nuclear torpedo for use against harbors. It was completely impractical, and due to the extreme secrecy surrounding it, was rejected by Soviet Admiral Kuzntetsov upon learning of it. The Project 672 Kit (NATO reporting sign November) was then given a conventional torpedo armament and went out to sea in 1958. It was a fast boat, with a given maximum speed of 28 kts, but its turbines proved unreliable and its reactor developed leaks after 800 hours. Less concerning was its noisiness, a factor Soviet submarine designers felt was less important than top speed, and a design choice that would plague Soviet nuclear submarines into the 1970s.
The nuclear submarine was a far more capable and deadly opponent compared to its diesel electric counterparts. Without needing to rely on electric power for underwater propulsion, a nuclear submarine was not restricted to a small patrol area, nor did it need to expose itself to detection to recharge. Furthermore, it was fast. As loud as the Novembers were, they were nearly twice as fast as contemporary diesel electric submarines. Lastly, their larger size enabled them to carry larger, more sensitive sonar systems and greater complements of weapons. In short, it was a faster, more alert, and better armed threat than anything the US Navy ever had to contend with.
The Novembers proved to be a wake up call to the US Navy, but their operational restrictions kept them from being perceived as a massive threat. For instance, they were not deployed to the Caribbean during the Cuban missile crisis, as the distance was deemed a hazard. The turbines aboard these boats were unreliable, and there was no wish to have their most advanced submarine being seen under tow. Subsequent developments would however be a more considerable concern to the US surface fleet. General Secretary Nikita Kruschev’s plan for the Soviet Navy was to be one that was capable of defending its own coasts using light warships armed with anti-ship missiles, and submarines which could stalk shipping lanes for enemy vessels. As opposed to Stalin’s views, Kruschev’s plan heavily favored the development of cruise missiles and submarines over a balanced fleet, and largely handicapped the development of larger warships.
The torpedo shaped November class was a massive, if clumsy, step forward for the Soviet Navy. While unreliability and loud acoustic emissions plagued these boats, they showed the promise of nuclear submarines to future Soviet naval planners. [US Navy]The immediate products of this philosophy were the Echo class nuclear submarines, and to a lesser extent, the conventional Juliet class. These new boats carried heavy, anti-ship cruise missiles and were initially considered a serious threat to US carriers. They were not, however, without serious limitations. They required cooperating patrol planes to share radar data for over the horizon targets, and needed to stay on the surface for up to thirty minutes before carrying out the attack with their long range missiles. They were accordingly extremely vulnerable when operating in areas without a substantial Soviet air presence. The more advanced Charlie class materialized after Kruschev’s fall, and was capable of submerged launches, but of slower and short ranged missiles. With Kruschev gone, the Soviet Navy largely abandoned any plans of Atlantic convoy raiding to pursue building better defenses against American Polaris missile subs, and later to focus on denying potential enemies access to bastions where their own SSBNs patrolled. Largely under Admiral of the Fleet Sergei Gorshkov’s direction, the Soviet fleet would try to right itself to become a more balanced force, so that it might better assist Soviet foreign policy, and to build up a defense against wartime incursions from enemy aircraft carriers and modern nuclear submarines.
In spite of the limitations of the Soviet nuclear submarine fleet of the sixties, their growing capabilities would prompt the US into developing their anti-submarine forces even further. Throughout the sixties, new aircraft ASW tactics were employed to replace the old snorkel-chasing methods. A greater focus was placed on the use of sonobuoys, which could be used to survey larger patrol areas, and the newer versions of which were growing ever more sensitive and sophisticated. Greater coordination with surface vessels was also employed, with newer destroyers and frigates mounting considerably more powerful sonar systems. Overall, US nuclear subs would take up an ever more important role in anti-submarine warfare, massive new hydrophone lines were laid in strategically important areas, and the aircraft carrier was soon to take a primary position in anti-submarine strategy.
Viking
In the world of the nuclear submarine and the jet carrier air group, the S-2 Tracker was becoming an ever more inconvenient asset. As carriers began to carry an ever greater number of jet aircraft, there was some frustration with having to still carry stores of aviation gasoline for the S-2s. The situation was not improved by the retirement of the WWII era converted CVS, which would be entirely out of service by the early 1970s. As a result, the entire surface ASW framework was to be restructured. Among the earliest moves was to announce a competition for the S-2 replacement in 1964, under the designation VSX. The new plane was required to have at least twice the speed, twice the range, and twice the ceiling of the aging Tracker. Lockheed was among the most promising entrants due to their previous history in designing maritime patrol aircraft, though their lack of experience with carrier based aircraft saw them partner with LTV Aviation, and the new ASW gear was to be designed by Univac Federal Systems.
A wooden mockup of Lockheed’s entry into the VSX competition. [US Navy]Lockheed’s Viking was a robust, high wing aircraft which featured a pair of turbofan engines for their power and fuel economy. The plane also carried nearly every modern airborne submarine detection system of the time. Its four crewmen operated the aircraft’s systems in coordination with a central, general purpose digital computer, which greatly aided the crew in processing the information gathered by the aircraft’s sensors. Further crew integration was accomplished through the use of multi-purpose displays that could show information from any of the aircraft’s crew positions. In addition to the MAD, radar, and sonobuoy systems, the plane was equipped with a FLIR system mounted to an extendable turret which was capable of detecting snorkeling, or near surface submarines and sea mines. To complement its sensors, the aircraft had a maximum speed of approximately 429 kts, a ceiling of 40,000 ft, and a maximum endurance of over six hours. Of the entries from Grumman, General Dynamics, and Convair, Lockheed’s design won out.
They were formally awarded the contract in 1969. The first of eight YS-3A prototype and pre production aircraft flew only three years after the contract was finalized in 1972, with the aircraft entering service two years later. This program was also the first to have a formalized set of milestones to ensure costs were kept low and technical risks were reduced. All program milestones were met ahead of schedule, and the plane was prototyped, built, and delivered in quantity in only five years. Their carriers too were modified to better suit ASW operations. In 1971, the USS Saratoga was the first to receive an ASW analysis center and support shops for ASW gear and weapons. All carriers but the older, smaller Midway class were able to receive the improvements. Prior to the introduction of the Viking, carriers operated S-2’s, with the introduction of the new aircraft vastly improving the anti-submarine capabilities of US carrier battle groups. The plane could perform an ASW search quickly at 35,000 feet at a speed of over 300 kts, a massive improvement over the S-2’s 135 kts at 10,000 ft. Even before considering the massive improvements in sensors and the centralized computer integration, the Viking could patrol truly massive stretches of ocean for a plane of its size. With a payload of four lightweight torpedoes and 60 sonobuoys, the Viking could fly out 826 nmi from its carrier, and conduct a two hour search before having to return. The use of external stores and airborne tankers could push this already phenomenal range out even further.
The unified CV concept brought together the anti-submarine and surface distinctions, as the old sub-hunting legacy carriers began to be decommissioned. The carrier’s air wing was tailored to its deployment goals. [US Navy]VS-21, the first S-3A squadron, was deployed aboard the USS John Fitzgerald Kennedy in the summer of 1975. During its Mediterranean deployment, the Kennedy was able to truly demonstrate the universal carrier concept. Previously, carriers were divided between the CVS, sub hunting carriers, and the CVA’s, which hunted everything else. The introduction of the Viking enabled the consolidation of all US carriers into CV’s, the new concept seeing carriers equipped for every conceivable mission. However, the S-3A was not the only newcomer to the ASW mission. The year prior to its first deployment saw the introduction of the Kaman Sh-2F Seasprite. This light anti-submarine helicopter would soon be found aboard most US warships, extending both their maximum search and offensive ranges. In short, the US surface fleet’s ASW capabilities had been thoroughly improved through the adoption of these two aircraft, well in advance of the predicted improvements in Soviet nuclear submarines.
An A-6 Intruder and S-3A Viking overfly a surfaced Project 641 ‘Foxtrot’ class submarine. These boats had improved fire control and sensors over the older Whiskey and Zulu class boats, but were otherwise built along the same post-WWII lines. Significant improvements in regards to quieting and hull form would not be achieved until the later Project 641B ‘Tango’. [US Navy]In service, the S-3A was primarily a screening element for the carrier group and any surface groups it might be supporting. A US carrier group is typically deployed alongside independent surface action groups and nuclear submarines, these often being the outermost defenses for the carrier group. The carrier’s offensive range and ability to survey thousands of miles of ocean make it the center of naval operations, and the most well defended asset. It was the job of the outer forces to screen the path and potential approaches to the carrier from enemy submarines, and to a lesser extent surface ships, though those more often fell under the purview of other aircraft and vessels.
Given the distance between these forces, gaps inevitably form, and these areas are typically patrolled by aircraft. In wartime, the Viking could quickly fly out to these locations and deploy a grid of sonobuoys, which it could maintain for several hours before being relieved by other aircraft. In addition to screening the path of the carrier, the S-3A could also be tasked to patrol the open ocean to search for older cruise missile submarines, which had to surface for long periods to fire their weapons. The S-3 would eventually receive Harpoons for this role, but initially, it would carry Hydra 2.75 inch rockets or unguided bombs. By the late 70s, these submarine ‘Shaddock’ missiles were easily defeated by the new EW systems and defensive weapons added to destroyers, cruisers, and carriers, but they still posed a threat to lighter warships and shipping. In addition to open ocean patrols and barrier searches, the Vikings could be quickly dispatched to support patrolling frigates and destroyers which were tracking submarines.
While the Victor class boats were primarily designed around the anti-submarine mission, they could fire salvos of two heavy weight, long range Type 65 torpedoes for use against large surface groups. The boat first entered service in 1977 and represented a major success in achieving low acoustic emissions in Soviet submarine design. [US Navy]Though the Soviet fleet consisted of a large number of these older submarine classes, new models of Soviet nuclear submarines would pose a greater challenge. A change in design philosophy would see a shift in focus away from achieving the best possible speed, to a balanced approach which placed greater importance on lower acoustic emissions. When commissioned in 1974, K-387, a Project 617RT ‘Victor II’, was the first Soviet nuclear submarine to incorporate rafted equipment. With its turbines suspended on vibration dampening mounts and its hull clad in anechoic rubber tiles, it was remarkably quieter than its forebearers. Further improvements to this class resulted in the Project 617RTM ‘Victor III’, with the first boat being commissioned in 1978. However, sound reduction was only marginally improved, with much of the focus being placed on new sensors, with the main mission for the sub being ASW. With 48 total Victors of all classes being produced, it represented the modern workhorse of the Soviet submarine force. More concerning to the carrier, however, were the successors to the Echo and Charlie class SSGN. The Project 949 ‘Oscar’ was a massive vessel which carried 24 P-700 ‘Shipwreck’ missiles, three times as many missiles as the Echo. Capable of submerged launches and engaging surface targets at long range, the Oscar lacked the handicaps of the earlier boats, and its state-of-the-art missiles boasted high speed and countermeasure resistance. A single Oscar could put the air defenses of a carrier battle group to the test, and thus long range anti-submarine screening became key for naval planners. The character of the Soviet submarine force of the eighties was rather peculiar, being composed mostly of obsolete to somewhat up to date vessels, but with a small and growing pool of cutting edge submarines.
Vikings among A-7 Corsair II and A-6 Intruder strike aircraft aboard the nuclear aircraft carrier Dwight D. Eisenhower, 1980. [National Archives]These ever-advanced models of Soviet submarines were anticipated and largely matched by the US Navy’s efforts to build a defense against them. All new warships possessed powerful new sonar systems and light ASW helicopters, and the carrier based S-3A sat at the center of fleet-wide anti-submarine strategy.
Into the 80s
While the S-3A proved an incredible new addition to the fleet, it soon encountered an unexpected challenge. As a result of the post-Vietnam defense cuts, the spare parts program for the Viking was among the worst affected. Stocks of replacement parts began to grow tight by 1977, though they would not pose a serious issue until the turn of the decade. As a result of stricter rationing of components, the mission readiness level of the Viking squadrons often fell to below 40% in 1981. However, the problem was soon identified and the procurement of more replacement parts began the following year, along with a new series of maintenance programs to increase readiness. Thanks to these efforts, the mission readiness of these squadrons climbed to 60% in 1983 and rose to 80% in the coming years, the highest in the fleet.
While the Navy was procuring additional parts, they also initiated a program to drastically improve the offensive and sensor capabilities of the aircraft. The Weapon Systems Improvement Program would seek to prepare the S-3 Viking for its service into the new millennium. Most of these improvements were focused around the aircraft’s sensor systems, most notably its new inverse synthetic aperture radar, which boasted a much higher capability in regards to periscope and snorkel detection, and its acoustic sensor suite. The acoustic data processor was improved through the use of a standardized naval signal processor which ran on a software shared among new naval maritime patrol aircraft, a new sonobuoy receiver boosted the available channels from 31 to 99, and it received a new, more reliable tape recorder for storing gathered acoustic data.
An S-3 passes a Kilo class submarine. While much of the Soviet diesel-boat fleet consisted mostly of obsolete classes like the Foxtrot and Romeo into the 1980s, the Kilo was thoroughly modern. [The Drive]In addition to its sensor improvements, the Viking received the new ALE-39 countermeasure system, and its electronic support measures were improved to allow better classification of contacts by their radar and radio emissions. Lastly, it finally received the capability to utilize the AGM-84 Harpoon missile, with the pair of missiles being mounted on the outer hardpoints. With a range of approximately 75 nmi’s, the sea skimming Harpoon could prove very difficult to detect and shoot down. As more effective air defenses against sea skimming missiles would not become widespread for almost a decade, the inclusion of this weapon would make the Viking a considerable anti-surface asset, along with its already impressive anti-submarine capabilities.
The sum of these upgrades would end up seeing the modified aircraft identified as S-3B’s, as squadrons began to receive the improvements in 1984. In addition to these upgrades and after the parts shortage, the scope of duties for the aircraft began to grow over the years. Among the first new tasks assigned to the Viking was to act as an airborne tanker. The long endurance of the aircraft, coupled with its incredibly fuel efficient turbofan engines, made it extremely capable in the new role. Carrying ‘buddy stores’, the S-3 could increase the range and endurance of cooperating carrier-borne aircraft in a much more efficient manner than the Ka-6d tanker, or a fighter or strike aircraft carrying the fuel tank and drogue system.
As the 1980s drew on, the Navy began to push the operational limits of the aircraft out ever further, and to great success. The S-3 took on the aerial mining mission, and during the Northern Wedding and United Effort exercises of 1982 and 1983, the operational search range of the Viking was pushed out to 1000 nmi with the use of airborne tankers. Even more noteworthy, they were able to detect and track submarines at that range during the exercise. While the S-3 Viking was initially introduced to serve a single, and very specialized purpose, the aircraft would end up proving extremely versatile and provided a number of new services to the carrier fleet, far beyond the expectations of its designers.
Operation Desert Storm and Late Career
An S-3B tanker launches from the deck of the USS Nimitz. [National Archives]As the Cold War came to a close, events in the Middle East soon culminated in the largest armed conflict since the end of the Vietnam war. As Iraq invaded the neighboring country of Kuwait over oil disputes, a coalition was built among Arab and Western militaries to oust Iraqi forces from Kuwait and deal a serious blow to Saddam’s forces. Along with a massive USAF contingent, the US Navy would deploy six aircraft carriers in order to dislodge the Iraqi army from Kuwait. Of the force, USS Kennedy, Saratoga, America, Ranger, and Roosevelt carried embarked squadrons of S-3B’s. USS Midway lacked a squadron of Vikings, as it did not possess an ASW analysis center.
A total of 43 Vikings would be active across these carriers by February 1991, where they would serve in a number of roles. Ironically, due to Iraq’s lack of a submarine force, ASW was not a role they performed during this conflict. These aircraft flew a total of 1,674 sorties between January 17 and February 28, 1991. The majority, with 1043 flights, were aerial refueling missions supporting other coalition aircraft. However, they also flew a number of reconnaissance, electronic warfare, and several surface air combat patrol sorties, these numbering 263, 101, and 20, respectively. The rest of their flights were categorized as unspecified support missions, or ‘other’.
Apart from aerial tanker duties, these Vikings flew most of their patrols to survey the Persian gulf, in order to track what few warships Iraq had, and to mark the location of mines. Some Vikings were also involved in the search for Iraq’s short range Scud ballistic missiles, a great fear at the time being that some of them may have carried chemical weapons payloads. They also performed a number of unorthodox tasks. For instance, the US carrier air groups could not electronically receive their daily air tasking orders from the coalition headquarters in Riyadh, Saudi Arabia. Their solution was to dispatch an S-3B to pick them up on a near daily basis. Among the most imaginative uses of the aircraft was in delivering photos from carrier based reconnaissance services to units fighting on the ground. This was done by placing the photos in an empty sonobuoy tube and parachuting them to units. One Viking also sank an unidentified class of Iraqi patrol ship on February 20, 1991, after dropping three unguided mk82 bombs on it. Offensive patrols were comparatively restricted and were conducted in areas with limited anti-aircraft threats.
A long exposure shot of deck crew preparing an S-3B on the USS Truman during Operation Desert Shield. [National Archives]After the end of the war in the Gulf, the S-3B was used for continued surveillance of the area and to uphold the sanctions on Iraq during Operation Desert Shield. It likewise performed similar support roles in the numerous NATO air operations over the former Yugoslavia. Their roles during those conflicts were almost entirely restricted to airborne tanker duties, though a number of Vikings, including a specialized ELINT model, performed signals intelligence missions.
As a result of the collapse of the USSR, the global submarine threat to the US Navy declined to almost nothing, and thus the Viking squadrons transitioned from anti-submarine, to surface control units to better represent their more multipurpose role. They would eventually discard their ASW equipment, with the anti-submarine mission being made the purview of the US submarine fleet and long range maritime patrol squadrons. Several new upgrades were initiated during the turn of the millennium, mostly in regards to new avionics and improvements to carrier landing aids. They would also include the Maverick Plus upgrade, which would enable the S-3B to use IR guided models of the AGM 65 missile, and the AGM-84H family of ground attack missiles. However, after the KA-6D left the service in the late 90s, the Viking would become the fleet’s primary aerial tanker.
The last major operation where the Vikings saw use was during the later invasion of Iraq, during which they primarily acted as tankers. There were, however, some strikes carried out by S-3Bs using the new Maverick Plus system, but these were comparatively rare. As the 2000’s came to a close and the US carrier force wished to divest itself of all but the most essential airframes, the Viking had fully left the service by 2010. The fleet was thus without a dedicated aerial tanker, and instead employed F/A-18s carrying ‘buddy stores’ to refuel other fighters.
Perhaps its later most publicized use was in delivering President George H.W. Bush aboard the carrier USS Abraham Lincoln after the invasion of Iraq. There, he delivered an address to the nation regarding the end of Operation Iraqi Freedom, in front of the long derided banner which simply read ‘Mission Accomplished’.
NASA
While the Viking’s military career came to a close, a number of aircraft were transferred to NASA as test aircraft in 2004. One of these planes was further developed into a dedicated testing platform in 2006 and was subsequently demilitarized. Most of the existing avionics were replaced with more contemporary civilian equipment and provisions for adding experimental equipment were installed. The Viking was given the civil air registration code N601NA and would see heavy use by the administration for the next 15 years, with the remaining Vikings being used for ground testing.
The NASA Viking proved to be an ideal platform to run a variety of experiments that required steady, precise flying at low speeds. [aionline]The plane was used for a variety of missions regarding aeronautic safety, aerodynamic studies, and Earth studies. Operating out of the Glenn research center, the plane tested engine icing under harsh conditions, flew communication equipment tests over much of the US to determine FAA guidelines for unmanned aircraft, and flew over the Great Lakes to study algal blooms. This Viking was the last airworthy example of the entire line, and was finally retired in July of 2021. NASA has since donated the plane to the San Diego Air and Space Museum.
Operating Characteristics
The high and broad wings of the Viking presented good low speed flight characteristics and high maneuverability. This was also aided by the lateral control system of the aircraft, which consisted of a set of small outboard ailerons, a pair of spoilers above the wing and one on the underside, and a leading edge flap. Pilots in both the Navy and NASA test programs praised the responsiveness and stability these systems provided. This ability was well valued during low altitude MAD searches and during low level communications testing for NASA and the FAA. However, at higher speeds, pilots needed to be aware of a degree of oversensitivity, as the aircraft did not possess a fly by wire system.
A view of a carrier flight deck from the cockpit of a Viking. [The Drive]The Viking had an extremely high carrier boarding rating thanks to its dynamic lift system, which in combination with the spoilers, gave the pilot a high degree of control during their final approach. The slow descent of the aircraft also permitted both the pilot and the LSO considerable time to make alterations. This is not to say this was a simple affair, as the aircraft was fairly sensitive to the air disturbance that forms immediately behind the moving carrier, and thus the pilot is still required to make the approach with caution. The engines had to be practically idled on the glide slope, and still often felt overpowered. The DLC system was essential, though the flaps were not, with many recoveries being flap up. Getting off the carrier was a far easier affair, as the aircraft only had a speed requirement of 120 kts under a normal load. Off wind catapult launches were made easily and some pilot and ground crew would remark that the Viking seemed like it could just fly off on its own. In both launching and recovery, the aircraft was remarked to handle well under poor conditions.
The addition of an APU in this aircraft greatly simplified and accelerated the start up procedure, as it did not require the pilot to request external power from the deck crew. A relatively simple start up enabled the aircraft to be ready some 15 to 20 minutes before its scheduled launch, and helped in speeding up the turn-over in deck operations. The only inconvenience the aircraft presented was that its low mounted engines were considerably quieter than most other embarked aircraft, meaning ground crew needed to pay particular attention to these aircraft as they moved across the deck. In short, the S-3 was very well suited to carrier operations.
A technician checks over the TACCO’s multipurpose display on an S-3B. The displays at each station were of slightly different dimensions. The TACCO station’s monitor was enlarged on the B model of the aircraft. [National Archives]A high level of crew cooperation was possible on the Viking thanks to the centralized nature of its avionics, sensors, and weapon systems. In managing all of these functions through its central computer, most crew functions were visible across all stations and, in some cases, could actually be managed between them. This was primarily achieved through the multipurpose displays at each station, which allowed crewmembers to share information. This made the SENSO and TACCO stations far more capable than they were on other aircraft, allowing for some division and management of the workload. The TACCO position likewise possessed a high degree of integration with the pilot and copilot, and in certain autopilot modes, could guide the aircraft to the weapon release point. All stations effectively had a high degree of situational awareness outside the aircraft, as the multipurpose displays could be set to show various airborne, surface, and subsurface contacts relative to their positions from the aircraft. The computer system itself proved fairly easy to manage, and designed with self-maintenance in mind. In the event of a system error, the computer could run a diagnostic and be reset in flight. Thanks to this level of digital integration, the Viking was viewed as being as capable as a number of patrol aircraft with significantly larger crews.
In the submarine hunting role, the Viking was in no shortage of equipment. The primary means of conducting an anti-submarine search were its sonobuoys. The aircraft carried a variety of these devices, which allowed for passive listening, or actively sending out an echolocating ping which revealed the positions of nearby submarines. These were often arrayed out in a grid like pattern in an aircraft’s patrol area to allow for the surveillance of a much larger area. They were typically dropped in line-like, or triangular patterns when used to try and get an accurate fix on the submarine’s location. Through acoustic analysis, the Viking was able classify submarine contacts by comparing them to existing sound profiles and was capable of gathering new profiles on vessels which had not yet had one compiled. Sonobuoys were usually dropped from the aircraft’s cruising altitude of 35,000 ft, though often from lower altitudes when a contact had been found and a finer pattern of the devices needed to be sown. The sonobuoy system was the first of its kind capable of accurately pinpointing the position of each device.
Sonobuoys provided a screen through which a transiting submarine could be detected, though they were not used for basic open ocean searches. The limited effective range of the individual devices meant that they were used for screening areas ahead of surface groups, filling gaps between other patrol areas, and investigating contacts that were beyond the range of other warships. The aircraft could hand off its sonobuoys to other aircraft from a shared channel, and could receive information from other, off-aircraft sensor sources through their datalink. Thus, in the submarine hunting role, the aircraft could either be a proactive tool, in performing its own searches, or reactive, in responding to suspicious or identified subsurface contacts from other aircraft and vessels. In concert with more modern anti-submarine assets, like the Spruance class destroyer or underwater hydrophone lines, the Viking could prove an incredible asset well beyond the limitations of its own sensors. The Viking was one of, if not the, best equipped ASW aircraft of the entire Cold War. Designed primarily around countering the threat of nuclear submarines, it would of course prove even more capable against diesel-electric submarines which presented more opportunities for detection.
Carrier deck crew load a sonobuoy into the aircraft’s external chutes. Viking’s could carry passive, active, dual purpose, oceanographic, and search and rescue beacon buoys. [National Archives]In conjunction with sonobuoys, the aircraft possessed its radar, FLIR optics, and a magnetic anomaly detector. The radar of the aircraft was designed to detect periscopes and snorkels deployed by near surface submarines. The key was to look for contacts that either appeared or disappeared from the scope without explanation, and was otherwise a very straight forward system. The FLIR sensor was used to detect heat sources, and in the submarine hunting mission, was used to spot submarines at a shallow depth, and the extended snorkel and exhaust of diesel-electric submarines recharging their batteries. Last was the MAD, which detected the magnetic field of a submarine, which caused slight disruptions in measurements of the earth’s magnetic field, hence the anomaly. This was the only sensor which required the aircraft to fly low, and the limited range of the sensor also meant a contact was typically only revealed if it was overflown. The radar and infrared systems were also important tools in conducting long range surface reconnaissance for the entire fleet. These systems were also necessary in providing targeting data for the Harpoon anti-ship missile.
In employing weapons, the majority of the work was done through the TACCO position. This crewmember assigned weapons to targets, and in coordination with the pilot and copilot/COTAC, delivered them. Originally, this meant he would deploy the Mk.46 lightweight torpedoes and depth charges, with the plane being capable of deploying nuclear models as well. Unguided munitions, typically Zuni rockets, Mk 82 iron bombs, or Mk 20 Rockeye cluster bombs, were the responsibility of the pilot and would have been used against surfaced guided missile submarines, or damaged warships. Later in the aircraft’s career, the TACCO would deploy mines, launch AGM 84 Harpoons, and later operate a variety of air to ground missiles with the introduction of the Maverick Plus upgrade.
The aircraft later excelled as an airborne tanker, where its ability to operate for long periods and at range from the carrier were crucial. The task was relatively simple enough, fly straight ahead while offloading fuel onto another aircraft through a hose and basket fuel transfer line. The asymmetric load of the fuel tank and drogue mount required constant trimming, which grew worse as the tank was drained, but this was a largely simple job the plane was well suited for.
Construction
A general diagram of the S-3B. [S-3B manual]The S-3 was a high wing, twin engine, carrier based anti-submarine aircraft. It possessed a very durable semi-monocoque airframe with three folding flight surfaces, being the wings and the vertical stabilizer. The fuselage was wide enough to permit the fitting of a considerable set of ASW gear, and an internal weapons bay. The general construction of the aircraft was fairly conventional in comparison to other carrier based aircraft. Lockheed was the primary contractor for the aircraft, with LTV building the wings, engine pods, tail assembly, and landing gear, while Univac provided the digital computer and some of the avionics.
The nose of the aircraft contained the radar, followed by the cockpit which seated the pilot and copilot, behind them were the weapons and sensor operators. Aft of the crew sat the forward avionics bay, which itself was over the internal weapons bay, and to the rear of it all was the MAD boom and rear avionics bay. On the underside of the aircraft were the sonobuoy shoots, which in addition to the 48 outer slots, held additional internal stores for 12 more devices. All critical systems had redundancy built in.
The landing gear, and catapult launch bar, were derived from those of the LTV F-8 Crusader and A-7 Crusader II. These consisted of a forward, upward retracting gear and two rear landing gear which retracted inward toward the fuselage. These are hydraulically actuated, though in an emergency, they could be extended by bypassing the hydraulics and letting gravity, and a leaf spring to force the gears into the extended position.
The wings of the aircraft were designed to permit a high degree of control and stability at both low and high speeds at low engine power, up to the maximum permitted speed of 429 kts. These were mounted high on the fuselage and possessed a high aspect ratio of 7.73 and a rearward sweep of 15 degrees. The wings consisted of an outer panel, which could fold inward, and an inner panel, roughly a third the length of the outer panel, which contained a fuel tank, and supported an engine nacelle and a pylon which could fit external fuel or weapons. The tall vertical stabilizer also folded down and to the port side to permit the aircraft to fit the carrier’s hangar doors. The extendable airborne refuel probe was stored just ahead of the wings.
Spoiler, aileron, and flap deployment diagram. [S-3B Manual]The Viking possessed an unusual flight control system which combined six large spoilers with a set of small ailerons and a leading edge flap. Lateral control was greatly aided by the inclusion of the spoilers in combination with the leading edge flap, which permitted effective control at very low speeds with low engine power settings. All control surfaces on the aircraft were deflected using hydraulically actuated servos, with an artificial feel system designed to give the pilot an idea of the extent of control surface deflection. These controls did however prove to be somewhat oversensitive at high speed. Overall, the control surfaces were very effective on patrols at low speed, though they could prove rather clumsy in a carrier landing pattern. This was largely due to the overpowered engines, which gave the aircraft a somewhat unorthodox glide slope and its large wings increased its sensitivity to the ‘burble’ air disruption behind the carrier. To compensate for this, the Viking was equipped with a dynamic lift control system which provided 12 degrees of speed brake extension and retraction through the upper spoilers.
The S-3 was powered by a pair of either General Electric T34-GE-2 or T34-GE-400A high bypass turbofan engines. These both produced 9,275 pounds of thrust at sea level, and the former was used only on pre-production aircraft. These engines used a dual-rotor, single stage, front-fan configuration with a bypass ratio of 6.23 to 1. These were divided into four major sections, being the fan, compressor, combustor, and turbine. The fan was driven by the low pressure turbine and produced 85 percent of the engine’s total thrust. The compressor was composed of 14 stages which compressed air prior to the combustion section, and provided the air for the pneumatic systems aboard the aircraft. The combustor section was where the compressed air was mixed with a fuel air mixture and ignited. The resultant flow drove the high and low pressure turbines within their own section, the high pressure turbine being responsible for driving the compressor, and the low, the fan. The air flow continues out the back of the low-pressure turbine to comprise the remainder of the engine’s thrust.
Standard and exploded views of the General Electric T34-GE-400A turbo fan engine. [S-3B Manual]The aircraft was fitted with a number of surface and subsurface sensors. The Viking originally possessed an AN/APS-116 search radar, which was primarily designed to detect the masts of submarines near the surface, but doubled as a general purpose surface search radar. This was replaced on the S-3B with the APS-137 inverse synthetic aperture radar which was more than twice as effective at detecting low RCS masts and had improved surface search capability. Specifically, it gained the ability to identify surface vessels at long range by comparing radar returns to existing 2D profiles of vessels. The aircraft also carried an AN/ASQ-81 magnetic anomaly detector fitted to an extendable boom at the rear of the aircraft often called the ‘Stinger’. The boom allowed the sensor to be placed farther away from ferrous objects on the aircraft, which might interfere with any measurements taken. They also carried the OR-89 FLIR sensor, it being mounted in an extendable turret on the forward, starboard side of the aircraft. The sensor would display surface and near surface contacts, making it extremely useful in detecting mines, submarines at a shallow depth, and the exhaust of diesel-electric submarines charging their batteries.
The Viking’s FLIR turret in its deployed position. [replane]What could be considered the primary anti-submarine sensor were the aircraft’s sonobuoys. Up to 60 could be carried in the chutes that sat flush with the outside of the aircraft and internal stowage. The aircraft communicated with minimal signal emissions and was capable of displaying their exact positions. Data from the devices was processed using an OL-82/AYS data processor and, coupled with its original receiver, was initially capable of monitoring 31 buoys. When upgraded, the acoustic data processor incorporated a new standardized UYS-1 signal process which had improved reliability and had parts and software commonality with other ASW platforms. A more advanced sonobuoy reference system, AN/ARS-2, would also boost the number of usable sonobuoy channels from 31 to 99 and an automatic channel scanning capability to search for available RF channels. The last upgrade to this system saw the analogue tape recorder switched from AN/ASH-27 to the AQH-4(V)2, which was both smaller, more reliable, and was compatible with the new UYS-1 signal processor.
The rear two stations of the S-3A Viking. The SENSO’s dual screens allowed him to monitor multiple sonobuoys simultaneously, this information being only partially available to the single screen displays at all of the other positions. [S-3B Manual]The aircraft’s countermeasures initially came in the form of the AN/ALR-47, a passive sensor which displayed radar emissions from search and track radars. This was later supplemented with the ALE-39, which included countermeasure dispensers. It also received electronic support measures, which allowed it to detect a wider variety of radar emissions to allow it to classify their emitters. In the event of being shot down, the aircraft was equipped with ejection seats. These could be used on the ground while the aircraft was still, and had a preset ejection sequence to prevent any collisions in air.
All of these systems were managed through a single Univac AN/AYK-10 digital computer. The system allowed for a much higher ability to process information compared to the isolated systems in use on virtually all other maritime patrol craft. Additionally, and perhaps much more importantly, it allowed the crewmembers to display information from their own stations to one another through a set of multipurpose display screens at every station. This allowed for the sharing of most sensor data across all four positions, though it was more limited in the case of sonobuoy readouts, as they were half displayed on a secondary screen at the SENSO station. These displays would give crews the ability to coordinate during surface and subsurface searches, and improve planning when preparing to attack. This was particularly valuable to the copilot/COTAC, whose job was to essentially direct the aircraft in achieving its mission. The addition of this system essentially gave them access to every senor and allowed them to work closer with the TACCO when it came time to deploy weapons.
Initially, the Viking could be armed with up to four Mk 46 torpedoes, being either the Mod 1 or Mod 5 NEARTIP during the 1980s. Both types measured 8.5 ft long with a diameter of 12.75 inches, and both carried a 95 lb warhead. The Mod 1 possessed a maximum speed of 45 kts,with the NEARTIP being considerably faster. The NEARTIP provided better tracking of faster targets and better countermeasure rejection, having incorporated a new sonar transducer, control and guidance group, and a new engine which switched from solid propellant to liquid monopropellant. The Viking would also receive the new electric Mk 50 torpedo in the early nineties, but it would shortly after transition away from the ASW mission. There were provisions for mounting up to four torpedoes internally from hardpoints rated up to 600 lbs each. The bomb bay could also carry up to four mines and depth charges, or two B57 nuclear depth charges.
Crewmen prepare to load a Mk 46 torpedo aboard an S-3A. [National Archives]The pair of external hard points could carry a combination of weapons, external fuel tanks, and airborne refueling systems. Initially, this was restricted only to unguided weapons and fuel tanks. Each hardpoint had a mounting capacity of 2,500 lbs and could carry up to three bombs through the use of the TER-7 bomb mount. The S-3B upgrade would allow the aircraft to use the AGM 84 Harpoon and was able to carry two of these sea skimming missiles. The last major upgrade package, which was installed around 2002, included a variety of avionics improvements, and the Maverick Plus system. This allowed the Viking to mount the AGM 65 Maverick, one per hardpoint, and the AGM-84E SLAM. The Maverick was to be used mostly against light shipping, with the SLAM providing stand off capability against ground targets. The SLAM could be guided manually after launch if a guidance pod was installed on one of the outer hardpoints. Both missiles were otherwise supported and targeted through a common display.
The S-3B could use any of the AGM-84’s in the Navy’s arsenal by the time of its introduction. The first of these was the Block 1B introduced in 1982, which had improved radar guidance allowing it to fly at lower altitudes. The subsequent 1C entered service in 1984 and incorporated a denser fuel, which increased its range by five nautical miles out to 80 nmi when launched from sea level, and added an alternate pop-up attack mode. The 1D entered service in 1992, with the lengthened missile possessing a range of 150 nmi and re-engagement capability, which allowed the missile to circle back to its target if it was deceived by chaff or electronic countermeasures on its first pass.
These sea skimming, turbojet powered missiles were exceptionally difficult to detect and intercept during the Cold War and flew at a constant Mach .85. These utilized active radar terminal homing, carried a 510 lb high explosive warhead, and had a flight reliability of over 93 percent.
Conclusion
A Viking prepares to launch after an F-14B Tomcat aboard the USS Nimitz during Operation Southern Watch, 1999. [National Archives]With the exception of the parts shortage, the Viking can be said to be among the most reliable and versatile tools the US Navy has ever possessed. The aircraft proved a phenomenally capable anti-submarine aircraft, which entered service long before high capability threats entered service in the Soviet Navy. When that particular threat had gone, the plane continued to serve ably, as a tanker, a reconnaissance aircraft, and limited strike aircraft. Finally, the venerable aircraft ended its career as a research aircraft.
S-3A Viking
Specification
Engine
T34-GE-400A
Maximum Continuous Engine Output (Maximum)
6,690 lbs (7,365 lbs for 5 minutes)
Combat weight at catapult
44,947 lbs
Gross Weight
36,574 lbs
Empty weight
26,581 lbs
Range [4x Mk.46 60xSonobuoys]
2,506 nmi
Combat radius [4x Mk.46 60xSonobuoys]
826 nmi for 6.9 hours at 346 kts
Maximum speed
429 kts at sea level
Crew
Pilot, Copilot/COTAC, TACCO, SENSO
Length (Folded)
53.33 ft (49.42 ft)
Height (Folded)
22.75 ft (15.25 ft)
Wingspan (Folded)
68.67 ft (29.50 ft)
Wing Area
598 sq.ft
S-3 variant
General Description
Number built/converted
YS-3A
Prototype/Preproduction
8 built
S-3A
ASW Aircraft
180 built
S-3B
ASW/ASuW Aircraft
160 converted from S-3A
US-3A
Cargo Aircraft
4 converted from YS-3A
KS-3A
Airborne Tanker
1 converted from YS-3A
ES-3A
ELINT Aircraft
16 converted from S-3A
Viking Squadrons
VS-21 ‘Fighting Redtails’
VS-31 ‘Topcats’
VS-22 ‘Checkmates’
VS-32 ‘Maulers’
VS-24 ‘Scouts’
VS-33 ‘Screwbirds’
VS-27 ‘Grim Watchdogs’
VS-35 ‘Blue Wolves’
VS-28 ‘Gamblers’
VS-37 ‘Sawbucks’
VS-29 ‘Dragonfires’
VS-38 ‘Red Griffins’
VS-30 ‘Diamondcutters’
VS-41 ‘Shamrocks’
(wikimedia, popular patch)
Credits
Article written by Henry H.
Edited by Henry H. and Stan L.
Ported by Henry H.
Illustrated by Hansclaw
Illustrations
Gallery
The Viking flying alongside the older S-2 Tracker maritime patrol aircraft. The S-3A rapidly replaced the Tracker from 1974 to 78, when the last Viking left the production line. [jrdavis]An S-3 is brought up to the flight deck in its stowed condition. The vertical stabilizer folds just below the rudder. [National Archives]A member of the USS Enterprise’s deck crew warms their hands in a turbine. Taken during the Fleet EX’88 Exercise off the coast of Alaska. [National Archives]A Viking prepares to launch from USS America. [National Archives]The evaluation S-3B aircraft passed its final trials in 1985. A rapid upgrade program would begin in 1987. [flight manuals online].S-3Bs on the crowded deck of the USS John C. Stennis in 2007. [National Archives]An SH-60 Seahawk comes in to land on the USS Kitty Hawk. [National Archives]A Sikorsky Sea King comes in to land on the USS Theodore Roosevelt. These helicopters and the Sh-60’s represented the inner circle of fleet anti-submarine defense. [National Archive]A Viking, among other aircraft, aboard the USS John F. Kennedy. [National Archives]An aircraft prepares to take on fuel from an S-3B tanker. Note the missing MAD boom and the covered sonobuoy chutes. [National Archives]The most publicized use of the Viking. ‘Navy One’ lands on the USS Abraham Lincoln with President George W. Bush aboard to deliver a less than well received speech after the end of Operation Iraqi Freedom. [US Navy]The ES-3 Shadow was an electronic surveillance aircraft which replaced the aging Skywarrior. It saw considerable use during the NATO intervention in the former Yugoslavia, where it monitored communications and radar emissions. It is easily distinguished by its dorsal equipment fairing [FAS]A Viking with its MAD ‘stinger’ deployed. [The Drive]
Sources
Primary
Standard Aircraft Characteristics Navy Model S-3A Aircraft. Commander of the Naval Air Systems Command. NAVAIR 00-110AS3-1. January 1973.
NATOPS Flight Manual Navy Model S-3B Aircraft. Commander of the Naval Air Systems Command. NAVAIR 01-S3AAB-1. September 2000.
NATOPS Weapon System Manual Navy Model S-3B Aircraft. Commander of the Naval Air Systems Command. NAVAIR 01-S3AAB-1.1. December 2002.
Fiscal year 1976 and July-September 1976 transition period authorization for military procurement, research and development, and active duty, selected reserve, and civilian personnel strengths : hearing before the Committee on Armed Services, United States Senate, Ninety-fourth Congress, first session, on S. 920
NASA fiscal year 2010 budget request : hearing before the Subcommittee on Science and Space of the Committee on Commerce, Science, and Transportation, United States Senate, One Hundred Eleventh Congress, first session, May 21, 2009.
Department of Defense authorization for appropriations for fiscal year 1982 : hearings before the Committee on Armed Services, United States Senate, Ninety-seventh Congress, first session, on S. 815.
Department of Defense appropriations for 1984 hearings before a subcommittee of the Committee on Appropriations, House of Representatives, Ninety-eighth Congress, first session / Subcommittee on the Department of Defense.
NASA’s aeronautics R & D program : status and issues : hearing before the Subcommittee on Space and Aeronautics, Committee on Science and Technology, House of Representatives, One Hundred Tenth Congress, second session, May 1, 2008.
Department of Defense authorization for appropriations for fiscal years 1988 and 1989 : hearings before the Committee on Armed Services, United States Senate, One hundredth Congress, first session on S. 1174.
Department of Defense appropriations for 1985 hearings before a subcommittee of the Committee on Appropriations, House of Representatives, Ninety-eighth Congress, second session / Subcommittee on the Department of Defense.
Department of Defense authorization for appropriations for fiscal year 1983 : hearings before the Committee on Armed Services, United States Senate, Ninety-seventh Congress, second session, on S. 2248.
Secondary
Chambers, Joseph R.. Partners in freedom: contributions of the Langley Research Center to U.S. military aircraft of the 1990’s.
Brown, Ronald J. Humanitarian operations in northern Iraq, 1991: with marines in Operation Provide Comfort.
Knaak, Jerry. A Hunting We Will Go. Naval Aviation News. March-April 1997.
Vikings Sweep the Seas & Viking. Naval Aviation News February 1983.
LSO School and the Paddles’s Profession. Naval Aviation News V70, November-December.
Benjamin, Dick. A Sea Rover for ASW. Naval Aviation News January 1972.
Richman, John P. The Viking at Home in the Fleet. Approach, July 1975.
Francillon, Rene J. Lockheed Aircraft Since 1913. Naval Institute Press. 1987.
Polmar, Norman & Moore, Kenneth J. Cold war Submarines The Design and Construction of U.S. and Soviet Submarines. Potomac Books. 2004.
Polmar, Norman. Aircraft Carriers a History of Carrier Aviation and its Influence on World Events Volume II 1946-2005. Potomac Books. 2007.
A flight of five No.101 Squadron Overstrands. (Boulton Paul Aircraft Since 1915)
The Boulton Paul P.75 Overstrand was a two-engined biplane that became the RAF’s mainstay bomber aircraft in the early to mid 1930s. The Overstrand was an improvement upon the earlier P.29 Sidestrand biplane bombers after the type recieved several criticisms regarding the frontal gunner position being exposed to the elements on such a high speed aircraft. To amend the complaints, Boulton Paul would design a modified version of the Sidestrand that would use a fully-enclosed powered turret, which would be revolutionary for the time. To test the design, three Sidestrands would be converted into Overstrands. The Overstrand would equip No.101 squadron and 25 newly built Overstrands would be constructed. Aside from mainline service, a number were experimentally modified by Boulton Paul, such as receiving different turret arrangements and more powerful engines. By the time of the Second World War, the aircraft had become obsolete, as new monoplane bombers entered production and replaced it. The type would continually fly in limited numbers for training and auxiliary purposes, but by 1941 would be considered obsolete and grounded.
Boulton & Paul and the Sidestrand
The Boulton & Paul P.29 Sidestrand was a modern and aerodynamic aircraft of the time. But while it was fast it had several glaring flaws, the biggest being the open front turret which exposed the gunner to high speed winds and cold air. (Boulton Paul Aircraft Since 1915)
In the mid 1920s, the Boulton & Aircraft company was beset by hard times. The company was surviving off of small orders for prototype aircraft and was in a rough financial state. The company had, up to this point, focused on creating twin-engine biplane bombers, starting with the Bourges in the First World War and going to their latest of the time, the P.25 Bugle. In late 1925, their savior would be their newest twin bomber design; the P.29 Sidestrand. It was an all-metal, twin-engine biplane bomber with extensive work done into designing its aerodynamic fuselage, creating an innovative and sleek-looking aircraft for the time. Production was soon ordered and 18 were built. This new bomber would populate the No.101 squadron, the only bomber squadron the RAF was operating at the time. Despite its success, a problem began to arise with the forward gunners of the aircraft. The Sidestrand, thanks to its aerodynamic design and powerful Bristol Jupiter engines, was able to achieve a top speed of 140 mph (225 km/h). While this speed made the twin engine bomber quite a fast aircraft for the time, this luxury was not so appreciated by the front gunners of the aircraft, who had no means of protection against the strong slipstream in their open cockpits. The strong winds made aiming the Lewis gun difficult, as it was blown around, and even reports of the propellers being hit by drum magazines thrown from the position were growing to be common. This was not to mention the extreme cold the gunner had to endure as well. Frozen fingers were another common complaint from Sidestrand gunners. While the Sidestrands began to take to the air (and torment their front gunners), Boulton & Paul set to procure more production orders of the type over the 18 that were built, but no further production was ordered, mostly due to the worldwide recession. In the early 1930s, many current fighters of the time were experiencing the same slipstream issues as the Sidestrand was. The Air Ministry put out an order on December 28th, 1932 to seek design reworks that would fix this now commonplace issue with the Sidestrand. While many of the other aircraft would seek simple means, the issue with the gunner position on the Sidestrand was more complex and would require more work put into redesigning the aircraft. Ultimately, Boulton & Paul would decide the answer was a completely covered turret. The company had been working on such a design with their P.70 aircraft concept.
The P.70 was a concept aircraft that was based off the P.64 mailplane and used components of the Sidestrand. While it was never built, it had an innovative enclosed nose turret that the Overstrand would use. (Boulton Paul Aircraft Since 1915)
The P.70 was a twin-engine biplane bomber design based on their earlier P.64 mailplane and incorporated aspects of the Sidestrand. In the nose of the P.70 was a fully enclosed, cylindrical turret that was fully powered via compressed air. The turret would have a single gun mounted that elevated and depressed down a vertical split in the design. It would also have 360 degrees of rotation as long as the gun was elevated 70 degrees to allow it to lift over the nose of the aircraft. Ultimately, the P.70 was not selected for the competition it took part in, but the innovative turret design was chosen to be used on the reworked Sidestrand. In addition to making the front gunner more comfortable, other additions were made for the rest of the crew. The rear gunner had a new windshield installed behind his back to protect him from the fast winds, and the pilot now sat in a fully enclosed cockpit. Even further, the aircraft would implement an onboard heating system, taking off excess heat from the engine intakes. Other planned changes to the design were the wings being swept at the outer edges to compensate for the weight of the front turret, and structurally integrity was also improved in the hull of the aircraft to allow for a bigger bomb load. With the improved design finalized, it was chosen that the first aircraft to test this new design, at this point called the Sidestrand V, would be created by modifying a Sidestrand III; J9186. The order for the creation of the prototype would be 29/33.
The mockup of the powered turret design. (Boulton Paul Aircraft)
Design
The Boulton Paul P.75 Overstrand was a twin-engined biplane bomber designed to improve the performance and crew comfort of the Boulton Paul P.29 Sidestrand. The airframe of the aircraft was of all-metal construction. The fuselage had a length of 46ft 11in (14.3 m). The wings of the aircraft were all-metal, 3-bay biplane wings. The wings themselves had an additional outer edge sweep to them, a design choice not found on the Sidestrand. This was to counter the increased weight of the nose due to the powered turret. The aircraft would have a wingspan of 71ft 11 in (29.2 m). Both the upper and lower wings would be built with ailerons. Mounted between the wings were two 580 hp Pegasus II.M.3 engines connected to two 4-bladed metal propellers. The engines were housed in nacelles that also carried a 17 gallon fuel tank, priming pumps, hand-stating magnetos and a gas starter. The very first Overstrand, which was converted from a Sidestrand, was equipped with 555 hp Pegasus I.M.3 engines. Covering the engine cowlings were 9-sided Townend rings. These assisted with improving the airflow of radial engines, reducing drag and increasing the overall speed of the aircraft. Connected to the engine nacelles on each side were the main connectors for the landing gear, which were each supported by struts. The Overstrand had large, rubber wheels that were bigger than those on the Sidestrand. The cockpit was located in front of where the wings connected to the main body. The cockpit itself was fully-enclosed with a sliding hood, a feature not present on the Sidestrand. The cockpit was glazed with anti-glare perspex. For the pilot, an autopilot was equipped, a feature also found in the Sidestrand. This was located directly behind the pilot’s seat. Behind the cockpit were two gunner positions near the middle of the airframe, one ventral and one dorsal. The dorsal firing position had a windshield installed to protect the gunner from the high speeds the aircraft would encounter. The ventral position would not have to deal with the rough winds due to the way it was positioned within the fuselage. The ventral gunner would also operate several pieces of equipment, including an F.8 camera, and a wireless set consisting of a T.1083 wireless transmitter, a R.1082 wireless receiver and a T.R.11 wireless transmitter/receiver. On the converted Sidestrands, they would continue to use the T.73 transmitter and R.74 receiver they came standard equipped with. Extra ammo magazines were availablefor all gunners. For crew communication, there was a telephone system installed that connected each of the crew members. For crew comfort, a heating system was equipped in the interior of the aircraft. Each crew member was able to appreciate the benefits of this system, no matter where they were located. Heat was siphoned from the Townend rings and engine cowlings through a series of ducts into the interior of the aircraft. Care was taken to make sure these ducts were clear of objects or debris when the system was activated, otherwise they would be forcefully ejected from the vents. At the tail end of the aircraft was a 9 inch by 5 inch tail-wheel, which replaced the landing skid of the Sidestrand. The vertical and horizontal stabilizers remained largely the same as how they were on the Sidestrand, but the rudder of the aircraft was lengthened. The Overstand also retained a rudder extension that was present on the Sidestrand. The horizontal stabilizers were supported by two struts on each side that connected to the fuselage.
A view of the prototype’s nose. On later models, the turret would be widened for increased crew comfort. (Boulton Paul Aircraft Since 1915)
The most innovative technical feature of the Overstrand was the powered turret at the nose of the aircraft. The turret design was created by H A Hughes, head of Armaments Section for Boulton & Paul. The design itself was originally part of the P.70 aircraft design, but with that project being canceled, the turret was reused on the Overstrand. The turret was cylindrical in shape, with the top and bottom being rounded. The majority of the turret was covered in Perspex to allow optimal viewing for the gunner, with the rest of the turret and frame being made of metal. The powered aspect of the turret came from pneumatic power from compressed air that was held in bottles. Each bottle was held at 200 Ib/sq and fed into the turret by an engine-powered air compressor at 40 Ib/sq. These bottles were rechargeable via the compressor and, at their full, could allow a total of 20 complete rotations of the turret before being exhausted. The turret itself was capable of 240 degrees of rotation with the gun pointing forward, and a complete 360 degrees if the gun was raised by 70 degrees. The turret was held on ball-bearings with brackets connected to the bottom and top longerons of the airframe. The top longerons in particular ended in a circular design that allowed rollers to rotate. The air was fed into the base of the turret, which was the main mechanism that rotated the turret. The armament of the turret was a single .303 Lewis machine gun, mounted to a mechanism that the gunner would use. The gun would protrude from a vertical slit at the front of the turret that allowed it to elevate. To protect this slit, a zip fastener canvas was put in place, but this was only found on the prototype Overstrand and was quickly replaced by a simple canvas strip held in place by clips. While the horizontal movement of the turret was done via pneumatic power, elevating the gun was manual. To assist the gunner in this regard, his seat and the gun mount remained balanced with one another and would raise and lower with the gun. Turning the turret was done via applying pressure to plungers on each side of the gun. To prevent the gunner from damaging the aircraft or turret, if rotated with the gun lowered more than 70 degrees to the rear, it would release the pressure from the plunger and stop the turret before the barrel could hit the body. The seat could also be adjusted manually by the gunner. For emergencies, the top dome of the turret could be removed to allow the gunner to exit. The top was held onto the turret via 3 pins, which were locked via pins with finger rings. Removing these three and pushing the top off allowed the gunner to escape. At the rear of the turret was a door that could be opened to enter the airframe of the aircraft. In addition to holding the gunner, the turret also served as the bombardier’s position. The bottom of the turret was heavily glazed to allow downwards visibility. Bomb controls were located to the left of the gun and were also duplicated in the cockpit for the pilot. The bomb sight could not be used in normal use and was stowed away. For bombing, the turret was locked forward into position and the gun moved so the bomb sight could be used.
Front and interior views of the powered turret. (Boulton Paul Aircraft Since 1915)
Aside from the frontal turret, there were two other gunner positions on the aircraft’s rear; one ventral and one dorsal. Both would use the same .303 Lewis gun as the main turret. Many improvements were done over the basic Sidestrand to allow the Overstrand to carry much more weight, including an enlarged bomb load of 1500 Ibs. Two 500 Ibs bombs could be carried internall,y with two additional 250 Ibs bombs on external racks on the fuselage, Additional racks could be installed at the front and rear of the fuselage, each carrying either 4 20 Ibs bombs or 2 20 Ibs bombs and two flares.
The Overstrand Takes Flight
A side view of the completed prototype J9186. This aircraft was converted from a Sidestrand III. (Boulton Paul Aircraft)
The modifications to Sidestrand J1896 would be completed around August of 1933. On its maiden flight, the aircraft would seemingly catch fire, as smoke poured from one of the inner wings. The craft would land immediately, the culprit being found to be caused by fresh varnish on the heating system ducts. Despite this incident happening on the first flight, testing continued on the aircraft. The early days of testing the aircraft yielded two incidents which could be considered quite humorous. After a test flight not long after the first, J1896 would have one of its wheels fall into a hole on the airfield, causing the aircraft to fall forward. One of the propellers would be destroyed and the nose turret would hit the ground. The current occupant of the turret was a member of the armaments section, someone who personally helped with the creation of the turret itself. When the turret dug into the ground, he began to panic and called out for help from the ground crew as he attempted to escape the turret. Due to his panicked state, he had forgotten how to operate the emergency pins that held the top of the turret on. The ground crew found his situation ironic, one of the men who had helped create the turret had forgotten how to operate it in his panicked state. He was in no danger whatsoever and the crew eventually helped the man out. Sometime later, the Air Ministry was intrigued in seeing the progress of the innovative powered turret system and thus sent an official to inspect it. The official was allowed to enter the cockpit to try out the new device. While trying the controls, he accidentally pushed on one of the plungers and began spinning. The gun itself had also been raised over 70 degrees, allowing a full 360 degrees of rotation. In a vain attempt to stop, the official leaned against the gun, and unknowingly onto the plunger; making the turret spin continuously against the intentions of the man. Humored by the situation, the design team that was showcasing the turret simply let him exhaust the air supply and finally let him out once the turret stopped spinning. The Overstrand would make its first debut to the public in late 1933, where it was part of the “Parade and Fly Past of Experimental Types” at the Hendon Air Display. On February 22nd, 1934, the prototype flew to be tested firsthand with the 101 squadron at Andover, who had been operating the Sidestrand up to this point. The main goal was to receive feedback on the changes to the Sidestrand’s design by its would-be operators, if the new additions were at all effective in increasing crew comfort. Aerial tests began and the crews liked the new design for a number of reasons, but they also had their criticisms. Being February, the heating system was very appreciated by the crews. Thanks to its Pegasus engines, the aircraft could attain a top speed of 153 mph (246.2 km/h) while still being as maneuverable as its predecessor. Despite all of this praise, pilots noted that the aircraft felt sluggish on the controls longitudinally and that the engines caused excessive vibrations. Gunners enjoyed not being subjected to harsh winds in the newly enclosed turret, but many felt it was currently too claustrophobic. With the necessary information received, the prototype would leave Andover and return on March 19th. Revisions began immediately to fix the criticisms of the design. A second Sidestrand was converted into this new design (J9770), and the new revisions were input into the modifications of this aircraft. The turret was widened to give the gunner’s more space. The zip-fastened canvas that protected the open slit of the turret was removed in favor of a simple canvas strip that was held on by strips. To accommodate the widened turret, the fuselage nose was widened to a slight degree. Changes were done to improve the autopilot, elevators, and fins to fix the vibration issues. The two-bladed propellers of the Sidestrand were replaced with four-bladed metal ones. Work was also done to make it easier to work on the engine’s compressors. The engines were replaced by the newer Pegasus II.M3 to increase performance and all would be equipped with this engine after this point. By this point in development, the aircraft design would receive a new official name, the Overstrand, named after a town near the city of Sidestrand, the namesake of its base design. Work began on converting two more Sidestrands (J9179 and J9185) into Overstrands not long after the second was completed. Further testing of the types revealed that the aircraft was still having issues with engine vibration. This would plague the converted Sidestrands but was noticeably more tame on the later production versions.
A side view of J9770. This was the 2nd converted Sidestrand and would evenutally be equipped with Pegasus IV engines. (https://www . destinationsjourney . com/)
While Boulton & Paul was in the midst of developing their new bomber, financial issues finally caught up to the company. With the failure to procure production contracts on several aircraft in the past and the Sidestrand itself not performing as well as had previously hoped, Boulton & Paul made the decision that of their four divisions of the company, the Aircraft Division had been the weakest. The Aircraft Division was completely sold off to a financial group, Electric and General Industries Trust Ltd, who would reformat the division into its own dedicated company that would be simply named Boulton Paul Ltd. Despite this drastic change happening with the development team, Boulton Paul would continue their work on the Overstrand starting on June 30th, 1934.
With the early success of the converted Sidestrands, the RAF put out an order (Specification 23/24) to Boulton Paul, which requisitioned the production of 19 newly-built Overstrands to begin replacing the Sidestrands in service.
In Service
A production Overstrand with a Sidestrand in the background. (Boulton Paul Aircraft Since 1915)
On January 24th, 1935, the very first Overstrand would enter service with the 101st Squadron. The squadron itself was already quite familiar with the design, thanks to the testing done the year before, as well as an Overstrand being flown by No.101 squadron members at the 1934 Hendon Air Display. Here, the Overstrand would participate in a mock dogfight against 3 Bristol Bulldog fighters (This display and the rest of the air show can be viewed at the Imperial War Museum’s website, found here.). The plan was to introduce the Overstrand slowly into the squadron, at first forming a third C flight and eventually replacing the Sidestrands in A and B flights. In late May, the Overstrands participated in a bombing demonstration to officials and students of the Imperial Defense College. The target was 200 yards by 300 yards and was meant to represent a bridge. All three bombing runs hit the target and impressed the students with their accuracy. Many however were not so impressed, as the demonstration did not represent accurate combat conditions the bombers would face in battle against a target that would no doubt be defended. Further showcasing of the new bomber continued as on July 6th, No.101 would fly to Mildenhall for the King’s Jubilee Air Review. While there, King George VI would personally inspect Overstrand J9185, and he was particularly interested in the powered turret.
With the necessary modifications made to the designs from actual criticisms of the prototype, the Overstrand and its many accommodations made the aircraft very well liked by the crews who flew them. The Overstrand was a comfortable aircraft to be in, but was also a well performing aircraft no less. At the start of its service, bomb aiming accuracy went up from only 15% accuracy to 85% thanks to the well thought out turret design which factored in bomb-aiming equipment. On top of bomb-aiming, the No.101 Squadron won the Sassoon Trophy of 1935 for photo-reconnaissance with a score of 89.5% accuracy. Gunner accuracy is also noted as having improved considerably thanks to the turret design.
Starting in September, newly produced Overstrands would begin entering service with the No.101 squadron. The first accident with an Overstrand occurred on September 9th, when J9185 crashed at the North Coates Range. Despite this accident, newly built Overstrands would continue to enter service through January of 1936. Before the year would close, an order for five more Overstrands (K8173-K8177) was placed, to serve as replacements in the event any were lost. This would bring aircraft production up to a total of 28 aircraft. While most of the Overstrands would be delivered to the No.101 squadron, K4552 would be sent to the Air Armament School at East-Church, where it would serve as a training aircraft for recruits to become familiar with the type and turret. 1936 was a largely uneventful year for the Sidestrand aside from 3 separate accidents. J9197 would lose an engine shortly after takeoff, K4556 would be forced down in a bog and K4562 would have its brakes seize up on landing.
The aftermath of the crash of K4556. (Boulton Paul Aircraft)
In January of 1937, the RAF began expanding its forces, and creating new squadrons. The No.144 Squadron was formed in support of No.101 and would borrow four Overstrands until new aircraft were made available. The Overstrands would serve for only a month until new Bristol Blenheim bombers could be supplied, after which the Overstrands were returned. Also in January, K4564 would crash while flying in thick fog from Midenhall to Bicester. Unfortunately, the aircraft would be destroyed and the crew was killed. Another aircraft would crash in June. A notice was put out to modify all Overstrands by reinforcing the nose to reduce vibration. Overstrands would once again appear at the Hendon Air Display, however, this would be the last year it was held. An Overstrand would perform a mid-air refuel with a Vickers Viriginia and yet again a mock dog fight would be held, this time an Overstrand would go against three Hawker Demon fighters.
The modified nose of K1785 with the de Buysson turret. (Boulton Paul Defiant: A Technical Guide)
In 1935, Boulton Paul purchased the rights to build the de Buysson electric turret from the Societe d’Applications des Machines Motrices (SAMM) in France. De Buysson was an engineer in the organization and had designed a four-gun electrically powered turret for use on aircraft. The French government was not interested in pursuing it, but de Buysson had caught wind of Boulton Paul’s work on turrets with the Overstrand. SAMM approached the company with their turret design and John North, lead aircraft designer at Boulton Paul, found their turret design superior and purchased the rights to its patent. In 1937, Overstrand K8175, one of the reserve aircraft, was experimentally modified with a de Buysson turret. The turret heavily increased the firepower of the Overstrand from a single Lewis gun to four Barne guns in the nose. Despite the increase in firepower, K8175 would be the only Overstrand to be equipped with this turret. The de Buysson turret would serve as the basis for the turret used in the developing P.82 turret fighter, which would be soon to be renamed the Defiant. Another Overstrand, K8176, would have its turret heavily modified to house a 20mm Hispano cannon. The nose of this aircraft had to be changed drastically to equip this weapon, and the turret was now built into the fuselage. The weapon itself was now on a mount that rotated and most of the glazing of the nose was removed, while what was necessary for bomb-aiming remained.
The modified nose of K1786 with its 20mm Hispano cannon. (Boulton Paul Aircraft Since 1915)
The P.80 Superstrand: A Bomber Behind the Times
Aside from the various modifications done to the Overstrand, there are two known variants that were proposed:
Early in development, Boulton Paul pitched an idea of a variant of an Overstrand that would be converted for coastal reconnaissance, designated P.77. While this idea was pitched, it was found to be largely unnecessary, as the Avro Anson could easily fill this role, and it was a modern monoplane design.
The P.80 Superstrand was meant to be the final evolution of the design, using Pegasus IV engines, retractable landing gear and a redesigned cockpit. While expected performance was much better than the Overstrand, the design was already outdated as it was being made, as newer and more advanced monoplane bombers were entering production, the need for further refining the type was made unnecessary. (Boulton Paul Aircraft Since 1915)
At some point during its service, the second Overstrand built (J9770) was re-equipped with much stronger Pegasus IV engines to increase performance of the aircraft. Plans were further done to modernize the design with retractable landing gear. The development continued with further refinements to the design, eventually becoming a new design entirely. The P.80 Superstrand was meant to be the final step in the bomber’s design, incorporating many modern aspects that were not found on the Overstrand. Aside from the previously mentioned Pegasus IV engines and retractable landing gear, the aircraft would also use variable-pitch propellers. The cockpit section was also redesigned, now connecting the pilot’s position with the rear dorsal gunner’s. The dorsal gunner position was also now fully enclosed. The front turret had many changes done to the design as well. Only the upper section of the turret would now be transparent, and it appears that the front section was now part of the fuselage, with accommodations in the nose for a bomb sight. It was expected these changes to the Overstrand would increase the top speed to 191 mph (307 km/h), give it a maximum ceiling of 27,500 ft and an increase bomb load. The Superstrand was never built, as the aircraft was obsolete even as it was being designed. While the Overstrand was performing well, aircraft development had continued and was now pushing towards more modern monoplane aircraft designs, the opposite of what the Superstrand was. Even Boulton Paul itself, by this point, was beginning to design monoplane bombers. The previous numeric design, the P.79, was a monoplane twin-engine bomber that, while never built, incorporated many elements found in the Overstrand but now adapted onto a more modern airframe. No further work was done on bringing the P.80 to reality.
End of the Line
Direct front view of an Overstrand. (Boulton Paul Aircraft Since 1915)
By 1938, the Overstrand was beginning to show its age. Modern bombers, like the Bristol Blenheim and even larger aircraft, such as the Vickers Wellington, had already, or were soon to enter production and replace the biplanes that remained in service. The Overstrand was no exception. On August 27th, No.101 squadron began gradually replacing their Overstrand bombers with Blenheims. By summer of next year, the Overstrand would be completely removed from frontline service. Despite this, the aircraft still continued to fly in various training schools and serve auxiliary roles. 5 Overstrands were sent to the No.2 Air Observer School in 1938 for training. K4552 would be sent to the No.1 Air Observer school in Lincolnshire, where it would continue its training mission until it was deemed non-airworthy and repurposed to a ground instructional frame. Despite not being in the air, the airframe was still the victim of accidents and, on April 28th, 1940, would be damaged and scrapped after a Gloster Gauntlet trainer overshot and hit it. The final nail in the coffin for most Overstrands came in July, when K1873 would break up mid air, killing the crew. After this incident, all Overstrands were ordered to remain in training as ground instructional air frames only.
K8175 parked in front of the aircraft hangar at the Boulton Paul factory at Wolverhampton. (Boulton Paul Aircraft Since 1915)
Despite this order, a handful of Overstrands would continue flying as part of rather unorthodox missions. K8176 would be sent to be used by the Special Duty Flight at Christchurch. Eventually, this aircraft would be sent to the Army Cooperation Development unit. K4559 would be operated by the Balloon Development Unit at Cardington. There, the aircraft would provide a slipstream for barrage balloons and would test the fatigue of the cables to the balloons. By 1941, the aircraft type was deemed obsolete and it is believed the previously mentioned aircraft were returned to Boulton Paul for turret development. Not long after, K1876 would be involved in an accident due to bad weather. While flying to Edinburgh, the aircraft would attempt to land at Blackpool but would undershoot the runway and crash. This is known to be the last time an Overstrand flew. It is interesting to note that K1876 had just been painted with camouflage, which would make it possibly the only Overstrand that was not in the standard bare metal finish aside from the prototype. It is unlikely any Overstrands saw any combat by happenstance during their short period of operation in the Second World War.
With the type obsolete, all remaining Overstrands were scrapped. While no surviving aircraft remain to this day, a reproduction of the nose section of Overstrand K4556 was built and currently resides in the Norfolk and Suffolk Aviation Museum, in the Boulton Paul Hangar.
Conclusion
The reproduction of the nose of an Overstrand at the Norfolk and Suffolk Aviation Musuem. (https://www . aviationmuseum . net/index . html)
Ultimately, the reason the Boulton Paul Overstrand existed was to improve the pre-existing Sidestrand’s nose gunner position and create a faster platform, which it would successfully accomplish with its reworks. The Overstrand served for only a few years before more advanced aircraft would replace it, but in that time it became a well respected aircraft that was liked by its crews for the various comforts incorporated into the design and which increased the performance.
The Overstrand was a very interesting aircraft, as it seems to be in an area between eras. On one hand, it represents the last of the biplane bombers that can trace their lineage back to the First World War for Britain and for Boulton & Paul. But on the other hand, it had features that were soon to become commonplace. The powered turret design was a game-changer not only for British aviation, but the company that built it as well. Boulton Paul, under H.A.Hughes, would become one of the most prolific turret designers for British aviation in the Second World War, not only designing turrets for use on other bombers, but also with their own upcoming turret fighter design, the Defiant.
Variants
Sidestrand Mk V -The name given to the design at the start of its development.
Prototype Overstrand (J9186) – The very first Overstrand was a converted Sidestrand. This had a smaller turret, two-bladed propellers and a narrower nose.
Converted Sidestrands (J9770, J9179, J9185)– The next three Overstrands built were modified from existing Sidestrands. However, these would be further improved over the prototype by having their turrets widened, four-bladed propellers installed and a wider nose to accommodate the bigger turret.
Boulton Paul P.75 Overstrand – Production version. 24 built in total.
Boulton Paul P.77 – Variant of the Overstrand redesigned for coastal reconnaissance. None were built.
Boulton Paul P.80 Superstrand – The final design of the “Strand” family, the P.80 Superstrand was drawn up in the mid 1930s as to further refine the Overtrand’s design with more modern components, including retractable landing gear, Pegasus IV engines, a reworked turret, lengthened cockpit and further streamlined airframe. Due to monoplane bombers now becoming mainstream, the P.80 was seen as obsolete and none of the type were built.
Modifications
Overstrand K8175 – Production Overstrand that was experimentally modified to test the du Boysson 4-gun turret.
Overstrand K8176 – Production Overstrand that was experimentally modified to house a 20 mm Hispano cannon in its nose turret via pedestal mount.
Overstrand J9770 – The second converted Sidestrand, this aircraft was later experimentally modified to house Pegasus IV engines. This was done as part of the development that would lead to the P.80 Superstrand.
Operators
United Kingdom – The Royal Air Force would operate the Boulton Paul Overstrand from 1935 to 1941 in various squadrons. Most of these would fly operationally with the 101 squadron from 1935 to 1938. The type would also briefly serve with 114 squadron for only a month, until it would be replaced by Blenheim bombers. During WWII, the remaining Overstrands would be relegated to training duties and other special tasks, such as working with barrage balloons.
3x Gunners (2 would also serve as the Bombardier and Radioman)
Armament
1x .303 Lewis gun in powered nose turret
1x .303 Lewis gun in dorsal gunner position
1x .303 Lewis gun in ventral turret position
1,500 Ib (680.4 kg) bomb load (2x 500 Ib and 2x 250Ib bombs)
Credits
Article written by Medicman11
Edited by Henry H. and Stan L.
Ported by Henry H.
Illustrated by Esteban P.
Illustrations
Overstrand J9186: The first Overstrand built, converted from a SidestrandOverstrand K4546: A production Sidestrand that was operated by the No.101 Squadron in their C Flight.Overstrand K1785: A later Overstrand that was experimentally modified with a quad-gun de Buysson turret for testing
Sources
Boulton Paul Aircraft. Chalford, 1996.
Brew, Alec. Boulton Paul Aircraft since 1915. Fonthill Media, 2020.
Mason, Francis K. The British Bomber since 1914. Naval Inst. Press, 1994.
The airliner Hansa prepares to depart from Potsdam. (stampcircuit)
Intro:
While the age of the airship has long since passed, these aircraft were involved in a nearly 30 year battle for aerial supremacy with the airplane. This competition would lay the foundations for modern air travel and, as the railway once did, change humanity’s conceptions of space. The Zeppelins of the DELAG airline earned the honor of being the first aircraft to regularly fly passengers, and to be the first to offer transatlantic air service from Europe to the Americas. While the destruction of the Hindenburg, operated by the DZR, spelled the end for passenger airship travel, DELAG’s airships had defined modern air travel with a near spotless safety record.
The Count
Count Ferdinand von Zeppelin was born in the Grand Duchy of Baden in 1838 as the second of three brothers to a fairly unremarkable aristocratic family. His father was an aristocratic native of the region and his mother being of French-Swiss descent. As a child, Ferdinand was educated by a tutor hired by his family before joining the Army at age 15 in 1858. He saw no action in the Franco-Austrian war in 1859, and in the peace before the Kingdom was embroiled in the wars of German unification, Zeppelin would continue his education. He took courses at the Stuttgart Polytechnic institute, the University of Tubingen, and the Royal War College. Zeppelin was an odd character, traditional, curious, fascinated with machines, and equal parts ambitious and stubborn.
He was far more adept in terms of his technical knowledge than other aristocrats, with engineering typically being reserved for young men of the middle class. Zeppelin, however, could not be considered a true engineer owing to the broadness of his studies. His formal education would end in 1861 when he began to travel Europe at the behest of the Army, observing the armies of foreign nations. He would travel to Austria, Italy, and France before finally making his way to the Americas, then embroiled in civil war.
Count Zeppelin during his time with the Union Army, pictured center. (wikiwand)
This journey, however, was a personal venture, the young Lieutenant Zeppelin having taken leave to see the conflict. He would arrive in Washington DC in 1863 where he acquired permission to travel with the Union Army after a meeting with President Lincoln. Zeppelin soon found himself in the headquarters of the Army of the Potomac in May, and was disappointed soon after. In short, apart from an impromptu escape from a Confederate cavalry patrol in Ashley Gap, Virginia, his experiences with the Union army were dull and uninformative. He felt that their ways of fighting were clumsy and dated, and that the openness and frankness of officers with their superiors was unprofessional and unwarranted. It seemed the entirety of the trip seemed a loss, militarily he found no new lessons or methods to be found with the Army of the Potomac. This was until he encountered Professor John Steiner, an aeronaut who formerly flew as a balloon observer in the service of the Union army.
By this time, the balloon had become a valuable, though uncommon, tool of the Union army, and a ride for thrill seekers. Steiner flew his balloon the ‘Hercules’ for the public after serving with the Union’s balloon corps. The Bavarian born aeronaut met Zeppelin in Saint Louis during the former’s diversion to see the Great Lakes. The two had very little in common apart from their first language and an interest in technology, which quickly sparked a long conversation over balloons and their operation. They spoke of the difficulties and limitations of the existing spherical balloon, which had to be tethered, lest it be carried off by the wind, and was almost impossible to keep them oriented in anything but the most mild weather.
With the end of their conversation, Zeppelin was eager to set off in the balloon. So eager in fact, that he purchased much of Saint Louis’ supply of coal gas to ensure his fight, to the annoyance of its residents. The two took to the sky on August 19, 1863, rising to around 55 meters. In the air, Zeppelin was not amazed or awestruck by the feeling of flight, in fact he never would be, but he saw in it both an immense promise and a series of problems to be solved. To the aerial observer, every detail of the landscape was revealed, and to a military man like Zeppelin, its value was evident and extraordinary. However, it wasn’t without its drawbacks. To his frustration, the balloon had to remain tethered, as uncertain winds could take the balloon any number of directions and Steiner didn’t believe they had enough coal gas for a long flight. The two would part ways after the flight; Steiner would later design and build his own portable hydrogen generator, and Zeppelin would return to Württemberg to resume his service with the army.
Zeppelin wouldn’t fly again for forty years and by the time he had returned home, he had largely thought the issues surrounding balloon flight were yet unsolvable. The Lieutenant would return to his homeland facing the Prussians, who were then seeking to establish their hegemony over their neighbors in a new central German state. Zeppelin was promoted to Captain and an aide-de-camp to the King in 1866. He would see no action, and witnessed the loss of the Austrian led coalition. Zeppelin remained in the army after the loss and was later married to baroness Isabella von Wolff.
With the start of the Franco-Prussian war, Captain Zeppelin was once again called into service, and with some good fortune, placed back on the path to aeronautics. Zeppelin would see action in this war, in the form of a daring, if brutal cavalry mission which saw everyone in his unit except him, killed or captured. He was subsequently honored by his homeland of Württemberg, and met with a decidedly cold reception by the Prussians, with whom he had developed a growing antipathy towards. However, Zeppelin’s key moment of the war came at the outskirts of Paris.
The Neptune was the first balloon to fly out of Paris, photographed here on 23 September 1870. (wikimedia)
When the war had been decidedly lost for the French, the capital remained a brave, but doomed, holdout. As Zeppelin waited on the outskirts of the city with the rest of the Prussian-led coalition, he noted the many balloons that departed the city. Numerous French aeronauts made flights out of the city, carrying news and letters out with them. Zeppelin once again saw the drawbacks of the balloons, the wind drew them in random directions, though most landed in friendly territory. He would still regard the balloon as questionable at best, and though he would take note of their ability to drift over the blockade safely, he lamented that they were totally unnavigable.
After the war Zeppelin remained with the army, being given command of the 15th Schleswig-Holstein Uhlans. For many years, he expected that this would be the end to the most exciting chapters of his life and prepared himself for a relaxing, if uneventful retirement. In all likelihood this would have happened, had it not been for a riding accident on March 18, 1874 (Robinson 9-13, Rose 3-12).
The Dream
After a particularly violent fall from his horse, Zeppelin was placed on several weeks of sick leave. During his recovery a fellow staff officer had come to deliver his well wishes, and some reading material, which included a pamphlet from the head of the new Imperial Post Office entitled World Postal Services and Airship Travel. The pamphlet, and a subsequent lecture Zeppelin attended, would set his imagination running. Soon he would begin accumulating basic airship concepts, though these early ideas proved very crude. Such was the case for a large airship which controlled its altitude solely through dynamic lift, and no ballast. However, from this early point he would also conceptualize the use of a rigid hull formed from rings and longitudinal beams which would contain a number of individual gas cells. Several features, like propulsion, were simply omitted as they had not yet been developed. It is curious that Zeppelin conceived of his first vessels without a way to move them, but in a period of such rapid technological development as the late 19th century, it was not an unreasonable assumption that the problem would be solved soon enough (Robinson 14). In Zeppelin’s case, the ‘suitable prime mover’ that his first concept used, materialized in less than a decade when Daimler produced the first series of reliable gasoline internal combustion engines.
Perhaps most crucially of all, Zeppelin understood the airship would operate as a series of independent components which could be developed, and improved upon separately. Its hull structure, gas cells, control systems, and propulsion could and would be developed in turn.
These developments, however, would be stalled for some years following the birth of his daughter, Hella, and his return to military service. This hiatus would only end with the end of the Count’s military career. By this time, the German Empire had only existed for some few years, and its second sovereign, Wilhelm II, was defined mostly by his insecurities and petulence. His greatest irritation were those in the Empire who still held to their regional identities and allegiances to their local Kingdoms and Duchies, over the Prussian dominated Empire. In this way Zeppelin found himself labeled a ‘peculiarist’ by the Emperor after he submitted a report in which he wished that the Army of Wurttemberg would retain a degree of autonomy and that its King not simply become a rubber stamp for the governing of the Empire. These sentiments instantly made him an enemy of the Emperor, and despite a glowing review from General Von Heuduck after the Imperial War Games of 1890, he was dressed down by the Prussian General Von Kleist in front of his fellow officers (Rose 19). At fifty two, his career was over and in its place was a desire to restore his name and all the time he needed to pursue what he’d set aside years ago, building airships.
Following his forced retirement, Zeppelin soon confined himself to private study on pursuing the airship. However, beyond his desire for restoring his name, he also worked against what he saw was the newest and greatest threat to Germany, French airships. Having previously written to the king of Wurttemberg over the success of the airship La France in 1887, he was now focused on designing an aerial warship to combat it. With his declaration of ‘help me build the airship for Germany’s defense and security!’ he established his own airship development firm in 1891 (Robinson 15).
La France was an impressive airship of its day, and inspired a panic in certain military circles. (wikimedia)
Zeppelin’s firm rapidly sent out requests for engineers, manufacturers, and workers to begin his work. Additionally, he also began a correspondence with General Alfred von Schlieffen, who directed him to the Prussian Aeronautic Battalion, the best hope for getting military interest in the airship. Zeppelin’s contact with Capt. Rudolf von Tschudi of the PAB was cordial, but to found he would need to provide an approved design before funding would be forthcoming for the project (Robinson 15). Zeppelin’s first major design was led by Theodore Kober, a twenty-four year old engineer formerly employed by the Riedinger balloon factory. It was almost entirely unworkable, with the two being far too inexperienced to carry out the project successfully. The airship was designed with a layout akin to a train, with a locomotive section at its front, being 117 m in diameter, 5.5 m in length, and with a volume of 9514 cubic meters. When the design was reviewed on March 10, 1894, Cpt. Hans Gross and Maj. Stephan von Neiber of the PAB, and Muller-Breslau of the technical college at Charlottenburg, would point out the design was unworkable for countless reasons. Zeppelin refused to accept the verdict and railed against his critics, only abating when Muller-Breslau agreed to consult with him on improving the design. The resultant airship presented a length of 134 m with a 13 m diameter, its hull was cigar shaped, and its hemispherical ends were replaced with tapering ones. Despite being at first very grateful for Muller-Breslau’s much needed assistance, Zeppelin never openly credited him for his work. Zeppelin would prove a difficult man to work with, and for Breslau, this was likely a better outcome as the count often took criticism very personally and rarely, if ever, forgave a slight. Zeppelin would harbor an intense and abiding hatred in the aforementioned Capt., later major, Hans Gross, who among other things, openly supported an unsubstantiated rumor that Zeppelin had appropriated the work of the then deceased aviator, David Schwartz. A duel between the two men was only stopped by the Emperor’s intervention (Robinson 22 Rose 50).
With the shape of the airship decided, what lay ahead were the no less important practical duties of building the firm’s manufacturing base, and finances. In short, Zeppelin’s airship was to be paid for mostly by his own fundraising efforts, with his joint stock company being established in 1898, to which he paid 300,000 of the 800,000 raised. The airship’s engines were among the first major steps forward for the program, with the Count having been in contact with the up and coming Wilhelm Maybach of DMG. The correspondence between the two would result in Zeppelin’s access to the new Phoenix engine, a two cylinder engine which included a spray-nozzle carburetor and a camshaft for controlling the exhaust valves. The lightweight engine was among the most advanced internal combustion engines in the world at the time, and by 1900 it would produce 16 horsepower. The engine however, was not so much as chosen for the project, as to boost the confidence in the effort overall, as the final design would use a different model. The design team was also shaken up with Kober’s departure after the airship’s redesign, Zeppelin was fond of the optimistic young engineer, but recognized that his inexperience made it impossible to head the project. In his place came Ludwig Dürr, a solitary, humorless, 22 year old engineer. Dürr was initially derided for his eccentricities, but his talents soon revealed themselves and he outshone everyone at the firm. Such were his abilities that he became the only employee to openly disagree with Zeppelin (Rose 54). In this first project however, his tasks were focused on the fabrication and construction of the airship, most of which had already been designed when he arrived at the firm.
Possessing the best power plants available, a workable design proposal, and a very capable engineer to head the project, Zeppelin prepared to begin the work itself. The site of construction and testing was to be Manzell, Baden-Württemberg, which sat on the Bodensee, a serene lake whose shores were spread between Austria, Germany, and Switzerland. The final construction and housing of the airship was to be done within a floating hangar on the lake. Zeppelin believed water landings were much safer, and the hangar, which was to be anchored at only one end, would be able to turn with the wind, which was a considerable safety feature. At the time, the hangar was the largest wooden building in the world, which amusingly enough, was secured only by a chain which anchored it to a 41 ton concrete slab at the bottom of the lake. Construction began on June 17, 1898 with components arriving from across Germany. The airship’s aluminum frame was supplied by the Berg factory in Ludenscheid, its gas cells came from the August Riedinger balloon factory in Augsburg, the engines were shipped in from the Daimler works at Carnstatt, its gas storage tanks came from the Rhine Metal works, and its hydrogen came from the Griesheim-Elektron chemical company from the city which was its namesake (Robinson 23, Rose 54).
Humble Beginnings
Zeppelin’s airships were first assembled ashore before being delivered and reassembled in the floating hangar. (wikimedia)
The construction of Luftschiff Zeppelin 1 was an arduous task which took almost two years. Zeppelin himself was involved in ensuring nearly every part of the vessel matched its specifications and that the components he was shipped were of acceptable quality. Safety was a top priority, one that kept the 62 year old count at the firm ten hours a day for nearly the entire duration of the construction process. When completed, the airship measured 128 m and 11.7 m in diameter, its hull was composed of 24 longitudinal beams connecting 16 rings, each composed of 24 beams which were bolted together and supported by bracing cables. This hull framework was made of aluminum, which easily made it the most expensive component, as the mass production of aluminum was not yet economical. Its lift and altitude control was achieved by means of 17 cylindrical hydrogen cells with a combined volume of 11298 cubic meters, in combination with water ballast. To propel it, the airship carried a pair of Daimler 4 cylinder gasoline engines which each produced 14.2 horsepower, and were connected to two pairs of two bladed propellers through a set of bevel gears and shafts. These engines were carried in a pair of aluminum control cars in which the crew sat, with the forward car equipped with controls for the gas cells and the airship’s few control surfaces.
Controlling the airship was done through two pairs of small rudders, placed fore and aft along the sides of the airship. To control its pitch, there was a weight placed along the narrow walkway between the control cars, which was manually winched between the two to achieve the desired pitch. Climbing was achieved entirely through dumping ballast and some small degree of dynamic lift as the airship was being propelled forward (Robinson 24, Curtis).
“It was an exciting moment. When the first command to let go the cable sounded from the raft, and the airship, which, up until then, had been held by the hands of the firemen, laborers, and soldiers, rose slowly into the air, and suddenly, at the height of 25 meters was released and soared upward” -Captain-Lieutenant D. Von Bethge, steamship inspector. (Curtis 9) (wikimedia)
The long awaited flight was primed for July, 1900, with the airship being floated at the end of June. Given that only a handful of aviators worldwide had any experience in controlled flight, Zeppelin himself would take the controls. When conditions were prime on July 2nd, the airship was withdrawn from its hangar before the waiting shoreline crowd and a number of onlookers who had arrived in their boats. Along with the more casual onlookers was the head of the PAB, Bart von Sigsfeld. Before all of them, Zeppelin took off his hat and led the crowd in a short prayer before he took a boat to the airship.
Zeppelin was joined in the front car by one of his company’s own mechanics, Eisele, and a personal friend and physicist, Baron Maximillian von Bassus. The rear car would seat the journalist and world traveler Eugene Wolff along with Gross, a Zeppelin company mechanic. The airship was untethered at around 8 in the morning where it was soon trimmed to level flight. The entire flight lasted some 18 minutes, and was cut short by the trimming weight becoming jammed, and the failure of an engine, though neither proved dangerous as level trim could be maintained by venting hydrogen, and the second engine provided enough power for the remainder of the flight. From the floating hangar, the airship traveled to Immenstaad under favorable conditions, with the entire flight spanning around 5 and a half kilometers. Even with these impediments, Zeppelin was able to bring the ship in gently on the surface of the lake before returning to its hangar.
While the crowds were thrilled by the exhibition, the PAB’s response was mixed. While Sigsfeld was thrilled by the demonstration, the other two representatives had understood that while the airship was safe and capable of navigation, its low speed, reportedly between 13-26 kilometers per hour by journalist Hugo Eckener, left it unable to travel in anything by the most placid weather (Robinson 26, Eckener 1). Perhaps of greater concern was the structural damage the airship had sustained during its flight.
The aluminum beams which comprised LZ 1’s hull had warped during its flight, and likely made worse when the wind had pushed the airship ashore after it landed. Unfortunately, the girders had been laid in a manner similar to the first airship concept, and provided little strength against torsional forces and seemed unable to adequately support the weight of the motor-carrying control cars. The airship’s hull was bent upwards at both ends, and was clearly operating on borrowed time. It was reinforced and sent airborne again on September 24, where it flew for an hour and a half, and again for one last time on October 17, where it reached a top speed of 27.3 kilometers an hour and maneuvered well against the wind. These flights, however, failed to convince the military that LZ 1 was much more than a clumsy experiment.
Unable to sell the airship to the army, or even fly his prototype again, Zeppelin dismantled the company, sold its assets, and laid off his staff, save for a handful of specialists. However, to the stubborn Count, this represented a short hurdle to be overcome, and soon he would begin new appeals for funds and resources while the diligent Ludwig Dürr began to design the next airship (Robinson 28).
LZ-2
Even with its limited test flights, LZ 1 had much to teach Zeppelin’s firm on airship construction. Dürr would revise its hull, using triangular section girders that could resist warping in all planes, and they would be built with a zinc-copper-aluminum alloy, instead of soft aluminum. He also reduced the number of sides to each ring section and shortened the overall length of the airship. LZ 2 would be far simpler, and stronger than the first design.
The flimsy and unreliable lead trim weight would also be removed, with pitch control being achieved by added elevators. The small rudders of the first design were also improved, using several parallel sets in a ‘venetian blind arrangement’. Its engines too were massively improved, with Zeppelin having access to Daimler’s new 85 hp motors, which now drove three bladed propellers. Redesigning the airship would prove a surprisingly straightforward process, with each component, the hull, the motors, and the control systems being addressed and improved upon in turn (Robinson 28, 29; Rose 73, 74).
What would not prove as straightforward, was fundraising. While the first airship found a number of financiers, few shared Zeppelin’s stubborn optimism in working toward his second aircraft. The previously reliable Union of German Engineers had become outright hostile towards the Count after the LZ 1 failed to find buyers, and the public was mostly indifferent to the project. The private appeals, which bore a good deal of capital for the first airship began to fail too, bringing in only 8000 marks.
However, the Count would end up finding the money he needed. His prime supporter, King Wilhelm of Wurttemberg, once again came through and authorized a state lottery which brought in 124,000 marks. Surprisingly enough, the Emperor too gave support to the project, after the Kingdom of Prussia initially denied Zeppelin a lottery. He subsequently provided an additional 50,000 marks and instructed the War Ministry to rent hydrogen storage equipment to Zeppelin at low cost. Much in character for WiIlhelm II, his support came not from any generosity or personal interest in the Count, but out of a desire not to be outdone, and thus be under threat, from the new French Lebaudy airships.
The French airship program continued to worry and motivate Zeppelin, here, the LeBaudy brother’s airship, Le Jaune, glides by the Eiffel Tower in 1903. (air and space mag)
The remainder of the sum, amounting to about 400,000 marks, was acquired through a mortgage of his family’s properties in Livonia. Along with material assistance from some of his past clients, principally Daimler and Berg, the airship would be built. In all, funding the airship would prove a far greater challenge than designing and building it. While the design work began after LZ 1’s dismantling in 1900, construction would not begin until 1905 (Robinson 29, 30 ; Rose 75).
Zeppelin’s firm began building LZ-2 in April, 1905 at the same wooden shed that housed the first, though it had since been brought to the shoreline. It would be completed in seven months, though a towing accident would see its nose dip into the water, which resulted in damage that wouldn’t see it fly until the beginning of next year. It would seem rather peculiar that Zeppelin would launch the airship during the windiest, and thus most dangerous time of year, but his hand had been forced by world events. The Russian Empire, where his mortgaged estates were located, was crumbling, and the properties held as collateral were destroyed during the 1905 revolution. Zeppelin needed results, and so he raced to launch his airship.
LZ 2 presented a series of major improvements to all of the former airship’s major components. (Wikimedia)
LZ 2 first took flight on January 17, 1906, with the Count once again at the controls, and accompanied by experienced balloonist Hauptman von Krogh, along with five mechanics. Wolff was prohibited from attending after criticizing the performance of the first airship. The flight was conducted extremely early in the morning, and with so little notice, one engineer, Hans Gassau, arrived wearing his slippers. While the weather was permissible, the flight got off to a rough start, as the crew dropped too much ballast water and the airship rose to some 450 m. After some ballast work, the crew achieved equilibrium and leveled off allowing the flight to begin in earnest. Almost immediately the airship demonstrated massive improvements as to its speed and controllability, with the craft reaching an estimated 40 kilometers an hour and demonstrating the ability to navigate in stiff winds.
However, in the midst of this promising flight, a serious problem arose. The airship proved longitudinally unstable, with its nose pitching up and down as it traveled at speed. This motion flooded the Daimler engines, stalling them, and to make matters even worse, the rudders jammed when resisting a harsh crosswind. LZ 2 was soon adrift over the lake, and it would be several agonizing minutes before they were overland and the airship’s drag anchor could be used. As the airship cleared the shore and drifted towards the Allgau mountain range, Zeppelin ordered the anchor dropped. The anchor found purchase in the frozen earth and the momentum of the ship drove it downwards as it resisted the anchor’s hold, bouncing against the ground and slowing it as it passed two local farms. Eventually it halted over nearby marshland, sustaining considerable damage from the ordeal. The crew dismounted the ship, tethered it at both ends, and left to return in the morning. Upon their arrival the following day, they found the ship had been torn to shreds in the night during a windstorm. Being tethered at both ends, the ship remained fixed and unable to turn with the winds, the forces warping the aluminum struts and tearing off wide sections of fabric (Robinson 30-33; Rose 77).
The stricken LZ-2, despite the violence of the crash and the exposure to high winds, its rubberized-cotton hydrogen cells were almost entirely intact. (Wikimedia)
Journalist Hugo Eckener recounted that the old Count was utterly heartbroken, and beside the wreck of his airship claimed it was the end. He ordered LZ 2 dismantled. Eckener naturally thought this the conclusion to his story, which he would continue to believe until some days later, when Count Zeppelin came to visit him. While the Count often detested most of the journalists who covered his experiments, he saw Eckener’s work, which was mostly concerned with engineering, as honest and constructive. He offered to confer with Eckener directly on future projects, and invited him to dinner several days later. Eckener rightly surmised that Zeppelin was prepared to reveal something greater at their next meeting, and he was proved correct. The Count was preparing to develop a new airship to compete with the Prussian Airship Battalion’s semi-rigid design for a new military project (Eckener 12, 13). Eckener readily joined the project both as both a publicist and a consultant, with his position to encompass more of the airship project in the coming years.
While LZ 2 can’t be regarded as more than a cumbersome and tragic project, Zeppelin wasted little time in gathering up the resources to capitalize on the intense military interest that had arisen around the airship.
The Winner
Practically undaunted from the loss of LZ 2, Zeppelin raced to produce a new airship for the army. One might think that the partial success of LZ 1 and the solo-ill fated flight of LZ 2 would have disqualified him, but at this early stage in aviation, Zeppelin was a leading pioneer in airship design. Disqualifying Zeppelin was not an option, and so, he joined the competition alongside August von Perseval, and the Count’s old rival, Gross of the Prussian Airship Battalion. His competitors produced a non-rigid, and a semi rigid airship respectively. However, by the time the Military Airship commision began, Zeppelin was the only aspirant to have already built and flown their design. In this way, he held a considerable advantage ahead of his opponents, despite the military commision being biased towards semi-rigid airships. In many ways, Zeppelin had already won the competition before it had even begun, as his immense technical advantage was cemented by his military background. With his foot in the door, Zeppelin soon received a gift of 100,000 marks from the Emperor, gained 250,000 marks from a Prussian state lottery, and a Government interest-free loan of 100,000 marks (Robinson 31; Rose 90).
LZ-3 included a series of new control surfaces, seen here in its late configuration (Wikimedia)
Zeppelin’s only real competition was the Gross-Bassenach, a fairly uninspired semi-rigid airship, as while Perseval’s blimp was fairly practical, it had very little room for further development. With Eckener’s appeals in the press adding to his credibility, all Zeppelin had to do was cross the finish line before his rivals. The race to build LZ-3 was on, and to save time it would use the same hull as its predecessor, even reusing the propellers from the wrecked airship. While the airship would be built on the same lines as LZ 2, it carried with it serious improvements in regards to propulsion, maneuverability, and its hydrogen capacity. Dürr would increase its capacity to 11428 cubic meters and fit the new ship with a set of triple box rudders, two pairs of vertical stabilizers, and two pairs of elevators. These modifications were refined at the engineer’s own homemade wind tunnel and would greatly improve the stability and maneuverability of the ship. However, the airship still lacked a set of vertical stabilizers, mostly as a result of the dated aerodynamic theories the Count still stubbornly clung to. Regardless, the new airship flew spectacularly.
On its first flight on October 9, 1906, LZ-3 traveled some 111 kilometers for two hours and seventeen minutes. It too proved fast, with a rated top speed of 39 kilometers an hour, with a highest claimed, and likely overly optimistic, speed of 53. Though perhaps more than anything, it carried eleven people aboard and possessed a maximum useful load of 2812 kilograms (Robinson 32). LZ-3 not only proved that Zeppelin’s airships were capable of navigation in windy conditions, but that they could do so when loaded with cargo. Many within the government were impressed with Zeppelin’s results, including Major Gross who, in spite of their rivalry, recommended that the Count receive additional resources for his experiments. This wave of support led Zeppelin to offer LZ 3 to the Military with a promise to build them two more airships. He also followed this deal with a series of claims so optimistic and absurd, only his finance man, Alfred Colsman, would repeat them. One such claim was that he would soon build an airship capable of transporting 500 soldiers and use heated air in place of hydrogen (Robinson 33).
The military would decline the offer, and the Interior Minister would state that the government would purchase no airship incapable of making a 24 hour long endurance flight. However the Count still had an excellent position. Zeppelin had practically beaten out his competitors and now had a good deal of confidence in military circles. Even the Emperor himself was pushing airship development both to ensure the German military stayed ahead of the French and draw attention away from a series of scandals in his court. In more practical terms, they extended him a payment of 500,000 marks to pay for a new, expanded hangar, to be dubbed the ‘Reichshalle’ (Rose92).
Seeking the military contract, Zeppelin would have LZ-3 improved with the goal of reaching the 24 hour endurance threshold. Its easily damaged forward elevators would be moved higher up to the sides of the hull, and its rudders would be placed between the horizontal stabilizers. The latter were made more effective, and enabled the airship to take off heavier thanks to dynamic lift, and the former less effective, and less responsive at lower speeds. Stability was further improved by extending the triangular keel forward and aft of the control cars.
After the move to the Reichshalle, the airship was refloated in September of 1907. Its next flight was on September 24, where it spent 4 hours and seventeen minutes over the lake. Several more flights were conducted with a number of guests including Dr. Eckener, the count’s daughter Hella von Zeppelin, Major Gross of the PAB, a Naval Representative Fregattenkapitan Mischke, and the Crown Prince. Its most impressive flight was during Mischke’s visit, when LZ 3, then piloted by Dürr and Hacker, conducted an overland flight lasting seven hours and 54 minutes, turning back when their fuel ran low. It was a notably more challenging flight, as the inconsistent air currents overland and the up and down drafts caused some concern. This was to say nothing of the 152 m altitude they flew at. In spite of the challenge, they flew some 354 km over Lake Constance followed by the Ravensburg countryside. Despite their success, they did not reach the threshold, and by the end of the year the airship was in need of new gas cells, and their supply of hydrogen, which the PAB had provided, had been fully expended. Things were not helped by a winter storm which pulled the floating hangar from its moorings and pushed it ashore, damaging LZ 3 in the process (Robinson 34-36).
LZ-3 over the Bodensee during an early point in its career (Zeppelin)
While LZ-3 did not reach the Interior Minister’s goal, it drew international attention. Despite this, the acclaim it won abroad was nothing compared to the excitement it generated across Germany. The turn of the century was a period dominated by immense technological and industrial development, where countries sought to distinguish themselves through cutting edge developments. Where Britain had its gargantuan high speed ocean liners, America, its skyscrapers, and France its groundbreaking film industry, Germany would have Zeppelin’s airships. Amateur aeronauts and students formed clubs to travel to see the airships as they glided over the Bodensee, and among the upper classes there was likewise excitement as balls were held in honor of Zeppelin’s achievement, and there was even talk of events to be held over a 300 meters in the air (Rose 96). While LZ-3 failed to meet military standards, the funds for LZ-4 would come as a matter of course. Its success was taken as inevitable, and with this in mind, LZ-3 was placed in long term storage as work on the next airship began.
LZ-4
LZ 4 at the floating hangar (Library of Congress)
Zeppelin’s next airship was once again an incremental improvement on the previous design, this new model being built to meet the 24 hour endurance requirement. Its production began shortly after LZ 3 completed its last flights for the year, with the skeletal hull of the new airship being assembled in the old floating hangar at Manzell in November 1907. Construction was finished on June 17, 1908, after it had traded places with the damaged LZ-3 in the restored Reichshalle. LZ 4 was designed to increase the endurance of its forebearer, and improve its mobility and maneuverability. It was lengthened to 136 m to accommodate a 17th hydrogen cell, increasing the total volume to 15008 cubic meters, and it received a large rudder at the nose, but this was removed after test flights revealed the arrangement to be inadequate. The gondolas too were enlarged to fit a larger 110hp Daimler motor (Zeppelin 15). A small cabin was also added along the keel, which was connected to a rooftop platform for navigation.
LZ 4 first flew on the twentieth of June, during which the airship turned so poorly that it soon made its return to the hangar, after which the aforementioned fore rudder was replaced by a large, semicircular aft rudder. The succeeding trial flights on the 23 and 29th would prove well as to convince the Count to embark on his most ambitious journey yet. Zeppelin would take his new airship over the Bodensee and across the Alps to Lucerne, Switzerland on July 1st. It proved exceptionally well, making the 386 km journey in 12 hours, setting records for both distance traveled and time spent in the air. Zeppelin’s airship traversed the picturesque, but dangerously windy Alps, and was met by crowds in the Alpine city. After a set of maneuvers to impress the crowd at the lake, LZ 4 departed for home. This was made all the more impressive as the airship traveled into a headwind on its return flight to Manzell through Zurich. Only one problem arose, this being that once the fuel in the main fuel tanks for each engine ran low, the engines had to be shut off while they were refueled from cans, leaving the airship at half power for several minutes. It would, however, prove only a minor inconvenience in the greater scope of the journey. Dr. Eckener wasted no time in working the press to promote this newest achievement, ensuring generous articles in Germany’s leading, and competing, newspapers Die Woche and the BerlinerIllustrirte Zeitung. Word soon reached France, Britain, and America, though it would only be an echo of the attention Zeppelin received within Germany. A week after his return, he received over a thousand telegrams for his seventieth birthday and King Wilhelm II of Wurttemberg, his longest and steadfast supporter, awarded him the Kingdom’s gold medal for the arts and sciences (Robinson 36 Rose 102).
LZ-4 lifts off (Loc)
The Swiss voyage would prove an immense success both in proving the airship a robust means of travel over otherwise rough terrain, and as a symbol of technological accomplishment which propelled the Count and his creation onto the world stage. As one might expect, the Count was now confident enough to attempt the 24 hour endurance flight which would ensure military interest, and allow him to sell his two airships. On July 13, 1908, LZ 4 was outfitted for the long trip and departed the next day, only to have to return after a fan blade broke on the forward motor. Further delays were caused when the airship collided with the hangar, resulting in damage to its hull and hydrogen cells. The next journey to Mainz was pushed back until August 4th, where it departed with incredible fanfare.
LZ 4 left with a crew of eight, which included Dürr, its designer, the Count’s old friend Baron von Bassus, and three veteran engineers, Karl Schwarz, Wilhelm Kast, and Kamil Eduard Luburda. They departed before an immense crowd, the largest share of which came from a nearby resort. Zeppelin, rather uncharacteristically, eschewed the typical maneuvers over the lake, and instead ordered the ship to its next destination at its best speed. LZ 4 would overfly several towns to the delight of crowds who were gathered by telegraph reports and special newspaper editions. In spite of the fanfare, trouble began in the evening when the engines began to run rough around 5:24 PM. After setting down at a quiet spot near Rhine at Oppenheim, they set off again, only for a more dire failure to crop up at 1:27 the following morning. Its front engine was shot and the rear motor was sputtering and smoking, having expelled what little remaining oil was aboard. With Stuttgart tantalizingly close, Zeppelin brought the ship down outside Echterdingen, around ten and a half kilometers outside their final destination. While they waited for a team from a nearby Daimler workshop, a crowd grew.
News of the grounded airship spread fast, and soon tens of thousands had begun to move. Thousands poured through the small town on bikes, carriages, wagons, and cars with the hope of seeing the airship. In all, some fifty-five thousand would assemble to see the Count’s airship, with some even being recruited by Schwarz to set up a make-shift anchor out of a carriage to hold the airship in place. The rest of the crowd was kept to a safe distance by what policemen and soldiers could be mustered. At around noon, concerns arose as the sounds of a thunderstorm made themselves clear. These concerns were soon justified as gusts of wind soon followed and began to pull the airship away from its moorings. The gale pulled the airship around the clearing as soldiers desperately worked the mooring ropes and the Daimler mechanic became worried enough as to leap from the front engine car. Schwarz worked his way through the catwalk and began to release hydrogen to prevent the airship from being carried high and away by the storm. He succeeded, but was unable to stop the winds from carrying the airship across the field into a stand of trees. Gas cells were shredded, the framework twisted, and in an instant the ship was alight. Schwarz lept, and in a terrifying moment on the ground, found himself covered in burning net and cloth. Miraculously, the mechanic cast off the debris and crawled through the burning wreck and, in his own words, ‘ran like hell’. Apart from Schwarz, a soldier, and his fellow mechanic, Laburda had also escaped the airship. The latter was merely singed, and the former left unconscious. Fortunately, there were no fatalities and those injured received prompt medical attention (Rose 108, 109).
The aluminum from LZ-4 being carted off from the site of the accident. (Wikimedia)
The crowd was horrified and left utterly dumbstruck having witnessed the destruction, and forlornly surveyed the wreckage. Zeppelin and the rest of the crew were similarly dismayed, having returned to the site from their hotel in Echterdingen and finding the warped aluminum frame of the airship across a charred stretch of Earth. The future British PM David Lloyd George was among those gathered, and having traveled hoping to see the airship would only find its remains. He would state “Of course we were disappointed, but disappointment was a totally inadequate word for the agony of grief and dismay which swept over the massed Germans who witnessed the catastrophe. There was no loss of life to account for it. Hopes and ambitions far wider than those concerned with scientific and mechanical success appeared to have shared the wreck of the dirigible. Then the crowd swung into the chanting of Deutschland uber Alles with a fantastic fervor of patriotism.” (Rose 110,111).
Dejected, the Count and crew returned to their offices in Friedrichshafen. They could have hardly expected what was waiting for them there.
The Miracle
While the accident had largely reinforced the skeptics in official circles, the public was not willing to let Zeppelin’s work come to an end. In the aftermath of the tragedy, thousands began organizing donations. What had begun with an off the cuff speech by a Stuttgart merchant Manfred Franck, to rouse the public to help build Zeppelin’s next airship, had become a national phenomenon. Soon the press echoed his words and were raising thousands of marks a day, and they were not to be outdone by public and private associations who alike, sent hundreds of thousands of marks to Zeppelin AG. Those who hadn’t the money, sent clothes, food, and liquor of varying quality, and had done so in such amounts that the resort town’s post office was incapable of sorting it. Following Zeppelin’s return to his offices in Friedrichafen, he had received some 6,096,555 Marks from the public (~$25-30 Million USD 2020).
Perhaps even more bizarrely, came the Government’s response. Despite Zeppelin’s inability to perform the 24 hour flight, they were interested in purchasing the rebuilt LZ 3 and commissioning a new airship of the same design as LZ 4, to be accepted into service under the designation Z-2. The Emperor himself would soon visit the Reichshalle hangar to inspect LZ 3 and award Zeppelin with the Order of the Black Eagle, the highest order the Kingdom of Prussia could bestow. In a further and ironic twist, he was also invited to the Imperial War Games, or Kaisermanover, where he accompanied the Crown Prince (Robinson 41-43, Rose 113, 114).
LZ-3 was the first airship to be sold to the German Military, where it spent many years in service. (Wikimedia)
Almost impossibly, Zeppelin had been propelled far further by his greatest disaster than he had his greatest success. Zeppelin had both the love of the public and a powerful presence in the halls of Government, and with his gifted fortune, he set off to expand the horizons of what was once a personal project. On September 3, 1908 the Count founded Luftschiffbau Zeppelin Gmbh, or Zeppelin Airshipworks Inc. What was once a small, dedicated team running out of a handful of facilities along the Bodensee, was transformed almost overnight into an industrial powerhouse. In the following years and under Colman’s direction, he founded a number of new enterprises under the parent company which would include the Maybach Motor Company in 1909, Ballon-Hullen-Gesellschaft of Berlin Tempelhof in 1912, to build hydrogen cells, Zeppelin Hallenbau of Berlin in 1913, to construct hangars, and Zahnrad-Fabrik in 1915, to build gear and drive shafts (Robinson 41, 42). At the center of all of this sat Friedrichshaven, which became the hub for all of these projects, and by 1914 the small resort town would grow to become the wealthiest city in Wurttemberg. As the headquarters for the new company, it would boast new homes for the workers, along with schools, groceries, a pub, and a performance hall. On top of all of this was a generous company life insurance policy, and free room and board for the families of workers who found themselves struggling.
In the months following the new founding of Zeppelin Airship Factory in 1908, the newly christened Z I (formerly LZ 3) was delivered to the army, where it served until 1913, along with the newly built Z II, its company designation being LZ 5. Z II was completed in May 1909 and was identical to its ill fated predecessor save for the omission of the ventral fin along the gangway, the cabin, and the installation of additional fuel tanks. Before it was delivered to the army, Zeppelin wished to demonstrate its capabilities with a 36 hour flight to Berlin. The flight began in earnest after two aborts, on May 29, 1909, and the airship proceeded through a dark and squally night on the way to Ulm. From there they once again met frenzied crowds as they traveled around Augsburg, Nuremberg, and Leipzig before having to turn back as the fuel supply was inadequate, with the flight being terminated at 21 hours. It was not, however, insufficient enough to prevent them from flying around and circling Bitterfield, the headquarters of their rival firm, Parseval. Apart from the airship receiving damage from landing on the only pear tree in a field during a night landing, which punctured the forward gas cells, they returned home with little else to remark upon. Following repairs, it was ready again on June 2, though it would not attempt a second flight before the army came to accept it on July 24. In service Z II would see no true military duties, but it would be a considerable tool for generating notoriety for the service. Its high point was a demonstration at the International Aviation Exposition held in Frankfurt am Main, in September and October of that year. Generally, the army did not consider any of the airships they were provided with suitable for general service and would not procure any more until new models were built. They would largely be proven right when Z II was shredded while grounded during a storm, with Zeppelin’s outburst over the army’s carelessness bringing his relations with them to a new low (Robinson 47, 58).
Regardless, Zeppelin sought to renew military interest with LZ 6. Once again, this airship was derived from LZ 4, though the heavy lateral driveshaft gears connecting the engines and propellers were swapped with a steel band drive to save weight, it used more powerful 115 hp engines, included passenger accommodations in the cabin, and lacked vertical stabilizing fins. A short fabric ‘rain skirt’ was also installed around the hull to prevent rain water from dripping on the occupants of the gondolas, but it was removed as the crew felt it unduly lowered the airship’s top speed (Robinson 49). Its similarities to the three previous airships was likely an influencing factor in it receiving no trial flight. Instead, Zeppelin would fly the airship straight to Berlin on its first outing for the Whitsunday holidays. Unlike his attempted flight in LZ 5, he would not be able to turn back, as he was expected to arrive at Tempelhof Field where the Emperor awaited him. He was firmly reminded of this in a series of demanding telegrams from the Emperor, something the Count would have to heed now that he was in the graces of the court.
Count Zeppelin with his airship during the Berlin trip. (Bundesarchiv)
The airship departed August 24th at the command of Dürr, the Count having recently undergone surgery and unable to make the flight until after the airship stopped to refuel at Bitterfield. Trouble arose several hours after departure, as the lighter steel band drives immediately showed themselves to be less durable than the bevel gears. A former navy man, Helmsman Hacker was able to repair the drive, but several hours later a cylinder crack stopped one of the engines. The airship stopped at Nuremberg, awaiting a mechanic from Daimler, this detour leaving them unable to depart until the 28th. Similar problems persisted with the drive bands, but the airship would make it to Berlin on the 29th, though not in the best state (Robinson 50). However, the crowds assembled there took no notice and upon landing at Tempelhof, Zeppelin shook hands with the Emperor as the crowd cheered. The Count would also meet Oliver Wright, famed American aviator and co-inventor of the airplane, though the two would see very little promise in each other’s work (Rose 120,122). The Count and LZ 6 would remain on the public tour for some weeks, and it required a good deal of work to get the airship running well again. They went so far as to borrow the propellers from the army airship Z II. After giving the first aerial tours of the city to members of the Reichstag and public officials around the country, LZ-6 would return again to the hangar at Manzell before being presented at the 1909 International Aviation Exposition at Frankfurt in September. From a temporary shed built on the grounds, the airship gave passenger flights up and down the Rhine. These flights attracted little military interest but captivated the public, and to them, it seemed that the long awaited dream of air travel had been made a reality.
LZ 6 from bellow. (Wikimedia)
LZ 6’s return would see it sent to a new tent shed at Friedrichshafen, with the former floating hangars to be dismantled. With its publicity tour over, Zeppelin sought to rebuild the airship in the hopes of selling it to the military. A third engine, a Maybach 150 hp model, was added in the former passenger cabin which was geared to a pair of hull mounted propellers, allowing it to make a new top speed of 58 km/h. This was later removed for some time after it was believed to be a fire hazard, being mounted so close to the ship’s hydrogen cells. LZ-6 would also temporarily receive an experimental radio set, though the sum of these modifications would be altered again in the spring when the ship was dismantled and rebuilt. It was lengthened by eight meters, the third engine was reintroduced in the rear engine car, and the stabilizers were reworked. The biplane stabilizers at the back were combined into a single, large stabilizer, from which the elevators and rudders hung. The aft ‘barndoor’ rudder was also removed, with a fixed, vertical stabilizing fin taking its place. In all, the ship could now make 56 mk/h and was far more stable in flight. This however, was not enough to convince the army to purchase it.
With the failure to sell more airships to the military, Zeppelin was in a bind. While the extremely generous public donations could keep him afloat for the time being, he would need to find a means of consistent income for the company. Colsman, the corporation’s finance chief, had a brilliant solution. Given the public’s incredible enthusiasm for the airships, naturally they would prove the ideal customer base, and thus he proposed the Deutsche Luftschiffahrts-Aktien-Gesselschaft (DELAG), or German Airship Transport Company. In other words, the world’s first airline.
The First Airline
Zeppelin detested the idea, as he considered his airships the weapon to make the German army unparalleled in field and to boost the prestige of the country by carrying the flag, just as the expanding German navy did. While he had once considered civilian applications for the airship in the 1890’s, years in the limelight and his rehabilitation in military circles had firmly shifted his view, to him, the airship was first and foremost a weapon. However, Zeppelin Gmbh. was not the small outfit driven by one unshakable nobleman like that which preceded it. The decision went before the board of directors, who decided in favor of the airline. DELAG was founded on November 9, 1909 with the hope of beginning operations in the summer of the following year.
The shrewd and energetic Colsman proved right, and it wasn’t long until he had amassed the three million mark starting capital and the backing of the famous Hamburg-America shipping line, who would be the primary means of ticket sales and advertisement. Many larger cities soon sent requests to be included, with the mayors of Frankfurt, Cologne, Dusseldor, Baden-Baden, Munich, Leipzig, Dresden, and Hamburg soon joining the airline’s board of directors, and with several seeing to it that airship sheds were assembled in their respective cities (Robinson 52, Eckener 15). While orders for commercial airships were placed, they proceeded to organize the first operations using LZ 6 and the newly completed LZ 7 ‘Deutschland’.
Deutschland was built along the same lines as the modified LZ-6, and was the first to carry passengers for the airline. It was a stretched design some 148 meters long with a capacity for 19,340 cubic meters of hydrogen and a useful lift of 4,990 kilograms, with up to 1,496 kilograms of that being fuel. However, its real innovations were found in the once austere sightseeing cabin. The former canvas box was now a comfortable sitting and viewing room, which was of high layer plywood construction covered in mahogany sheets with mother of pearl inlays on its pillars and ceiling beams. The carpeting and comfortable wicker furniture added to the finery, and given the length of the flights, a small galley with matching aluminum cutlery was also wisely included. Lastly, it was the first to carry a lavatory, it also being aluminum to save weight. Behind all of this were a series of aluminum struts and cables which anchored it firmly to the hull (Robinson 55, Rose 134).
The Deutschland was still very much a derivative of LZ-3, which while versatile, was dated. (Wikimedia)
It was captained by former Prussian Airship Battalion Captain Kahlenhberg, as despite the several airships flown over the years, there was no sizable pool of experienced aviators to recruit from. The foremost of these were Zeppelin himself, who could not be convinced, and Dürr, who was otherwise occupied in his role as head designer for the firm. The first flight would be to Dusseldorf, the city which managed to complete their hangar first. It was scheduled for June 28 with a passenger list of 23, mostly journalists who had been invited by Colsman. The expectation was a flight of three hours, which began after a breakfast of caviar and champagne. Unfortunately, the crew had departed without a weather report. After the failure of an engine, the ship was left floundering in higher than expected winds. Deutschland struggled for hours through turbulence, violent gusts, and rain with one officer making the mistake of telling a concerned passenger ‘we do not know what will happen.’ Captain Kahlenburg was unable to prevent the underpowered, unbalanced airship from making a crash landing in the Teutoburg forest. Thus ending the short stopover flight that became a nine hour endurance test for everyone aboard. Apart from a crewmember who made a dramatic leap from the rear gondola, and fractured his leg, there were no injuries. Understandably, the journalists’ impressions were quite poor and the airship was disassembled and shipped back to Friedrichshafen where it would be rebuilt (Robinson 56 Rose 136).
Kahlenburg was laid off, and in his place Dr. Eckener became both a pilot and head of flight operations for DELAG. His first action was to familiarize himself with airship piloting on LZ 6, making some 34 flights, though this airship was soon damaged beyond repair after a fire in its hangar. With this accident, hopes were placed on the up and coming LZ 8 Deutschland II, made mostly from the reclaimed material of the previous ship. LZ 8 was identical to its ill-fated predecessor, and was likewise as ill-fated. With Eckener at the helm on its first passenger outing, he allowed himself to be pressured by the crowd to bring out the airship in a dangerous crosswind. Deutchsland II was subsequently knocked alongside the hangar and bent out of shape. Eckener claimed this cured him of all recklessness thereafter, and he subsequently went to completely reform flight operations at DELAG (Eckener 16).
The rebuilt Deutschland was met with an end that was as embarrassing as it was avoidable, but it thankfully motivated such a strict safety regimen that DELAG never suffered such an accident again. (Wikimedia)
Dr. Eckener isolated the causes of accidents that had plagued operations thus far, and focused on ensuring that DELAG airships would be crewed by veteran airmen who would have the benefit of extensive weather reports and more reliable equipment. The board was willing to give it another try, and authorized the construction of a new, modern airship. This new ship was LZ 8 Schwaben, which was shorter, more maneuverable, had a useful capacity of 6486 kilogram, and used new 145hp Maybach engines which would prove far more reliable. It made its first, and very promising, trial flight on June 26, 1911 where it made for 75 kilometers an hour (Robinson 59). Many of these advancements came as a result of Dürr accepting a variety of new concepts from junior designers, key among these was in rejecting the continuous lengthening of airships to boost their lift, and placing a greater focus on theoretical testing and problem solving, rather than building a ship and continuously modifying it as difficulties arose.
Schwaben was the first Zeppelin to have all its control surfaces at the rear, where they would remain on all future Zeppelin airships. (SFO Museum)
Along with the new airship came a series of reforms to DELAG’s flight guidelines. Crew training was standardized and captains in particular were required to have a thorough understanding of their vessels and to have participated in 150 flights before they would be allowed to command an airliner. The training program would be so successful that the military would send their crews to train with DELAG during their off season. Some would even fly passengers during the airline’s regular service (Rose 138). These procedural improvements were to extend to the ground crews, both to improve the tricky process of moving an airship in and out of its shed, and to avoid the kinds of accidents such as the one which claimed LZ-6. In that case an unmarked can of gasoline was thrown over a fire in the hopes of dousing it. Facilities were thus overhauled and staffed with thoroughly trained professionals. Perhaps most importantly of all were the stations for meteorological reporting. Unlike Kahlenberg, future DELAG captains would benefit from near nationwide weather reports from the series of meteorological stations which captains could contact at any time over the radio. Even without the radio they would have access to wind maps which charted the typical currents over Germany and allowed captains to safely determine new courses should their first choice be unavailable. Should all else have failed, emergency depots were established along common routes where airships could stop for repairs and fuel.
In order to avoid accidents while departing the hangar in a cross wind, the airships were tethered to trolleys called Laufen Katzen, or running cats after being likened to cats running across the top of a fence. (SFO Museum)
With these improvements, Schwaben was well equipped when it began passenger service in the summer of 1911. With all the methods worked out and potential dangers addressed, passenger flights went off without a hitch. A typical flight saw passengers assemble early in the morning, when winds were at their weakest, and allowed them to see the airship as it was serviced and brought out. When they departed the airship was almost impossibly smooth as it pulled away from the ground and began its journey. While the passengers traveled to a variety of locations and took in the view they were provided with a series of refreshments. The meager provisions aboard Deutschland paled in comparison to what Schwaben’s passengers enjoyed. Along with a considerable wine list that boasted a selection of Rhine, Moselle, and Bordeaux along with champagne, passengers were served a selection of cold dishes such as caviar, Strasbourg pate de foie gras, and Westphalian ham (Robinson 59). All of this was enjoyed in relative silence as the canvas skin and hydrogen cells dampened the sound from the propellers.
The main attraction beyond all of this was the view of the country from the air, as while this was a passenger service, its lack of fixed schedules could mean a wait of several days as weather cleared or repairs were made. Tickets too were steeply priced, owing to the limited number of seats aboard and high operating costs. A ticket could cost between 100 to 600 marks depending on the destination, though many passengers didn’t pay for their own seats as they were invited to garner publicity for the service. It was very common for periodicals and newspapers to send their own aboard to gather material. Along with journalists were VIPs, such as notable public figures, and foreign dignitaries the state wanted to impress. Those unable to purchase a ticket had the option of watching one of the many films made aboard the airliners or visiting one of the many DELAG airports located across Germany.
In the several weeks following its entrance to service, Schwaben was a hit. After the miserable year of 1910, it seemed as if the airline had not only been improved, but practically perfected.
The Golden Years
Viktoria Luise would introduce a number of notable improvements, chief of which was a larger passenger compartment. (Wikimedia)
As Schwaben was refitted following its stowage in the previous winter, it was joined by a slightly larger airship, LZ 11 Viktoria Luise. Named for the Emperor’s daughter, its design and performance were nearly identical to the Schwaben, save for its redesigned elevators and rudders. The year would start well, though an accident would leave Schwaben burned on June 28. It was traced to a static discharge caused by the rubberised fabric which formed its hydrogen cells. No one was aboard the grounded airship, though the public was momentarily disquieted. To allay fears, the Dusseldorf maintenance team took the blame while Colsman quietly shifted to the use of cells made of cotton and goldbeater’s skin. This material was a finely woven cotton fabric laminated with chemically treated sheets of cow intestine, which while unpleasant to produce, was lighter than the rubberized fabric while remaining just as durable, and removed any chance of static discharges (Chollet 6). Apart from the loss of Schwaben, operations continued without trouble for the remainder of the year.
Operations were expanded by a new airship, LZ 13 Hansa, named for the medieval Hanseatic league of merchants which spanned the Baltic. Identical to the Viktoria Luise, it was completed July 30 and took Schwaben’s place. For the remainder of the year Viktoria Luise and Hansa operated out of the double hangar built in Hamburg, where at the end of autumn, they were used to train the first Naval air crews. At the end of this training period, Hansa was flown over the High Seas Fleet Parade and the naval maneuvers that followed it. Ironically, Zeppelin’s civilian operation had managed to capture the military’s interest more so than any direct appeal.
Passengers sightseeing aboard Hansa. (Ryan Smith)
By the start of the 1913 season, DELAG was an international sensation, and in Germany, a technological achievement of immense pride. Shortly after Hansa and Viktoria Luise had entered service, they were joined by LZ-17 Sachsen. This ship, named for the region it would service, was slightly shorter than its contemporaries though built with a wider diameter, and held the highest lifting capabilities of the three . It was completed on May 3, 1913 and was sent to a shed at Leipzig where it operated from thereafter (Robinson 333). During the summer season all three ships were in service, and each operated out of its own region. Hansa left Hamburg for Potsdam, to service Berlin, and Viktoria Luise was sent to Frankfurt.
Hansa comes in to land. (Wikimedia)
These regional flights would ensure the airships were seen over and around most of Germany’s largest cities. What was once a curiosity that rarely strayed from the Bodensee was now a common sight for millions of Germans, one that stirred both patriotic fervor, and a curiosity and optimism for what the future held. While a relatively small proportion of Germans would ever fly aboard these airships, they drew massive crowds around the cities they visited and at the sheds where they were stored. Sadly, the entire enterprise was cut short by the beginning of the Great War, and the airships were turned over to the military during the period of general mobilization. Practically overnight, DELAG had ceased to exist, and in the end, it’s difficult to know how successfully DELAG would have been had it continued to operate its three airships. When its airships were pressed into military service, the company was still operating in the red, though its operating costs were plummeting and the proportion of paying versus invited passengers had climbed steadily. Regardless of its financial forecast, DELAG’s technical achievements would not be rivaled again for over twenty years. Its airships carried a total of 34,208 passengers over a distance of 1,172,529 kilometers, nearly five times the Earth’s circumference (Rose153).
The Zeppelin at War
Despite the Count’s enthusiasm that his airships would prove a decisive weapon in any war to come, this would not prove to be the case. In the years DELAG was operating, the German military had received a number of airships, though they never effectively developed their offensive capabilities. Both the Army and the Navy possessed a small fleet of Zeppelin airships, each with very different missions in mind, with the Army placing an emphasis on bombing, and the Navy on reconissance. In contrast with the well coordinated and professional civilian operation, both the Army and the Navy would suffer numerous accidents, the worst of which befalling the Navy’s L.2. The ship burned as a result of design choices from the Naval representative, Felix Pietsker, who was at Friedrichshafen to oversee its construction. He demanded the airship’s keel be placed within the hull to streamline it and bring the engines in closer to the hull, both choices being strongly criticized by Dürr as being unsafe. During a test flight, the inner keel collected leaking hydrogen, which otherwise would have exited through the top of the airship, and was subsequently set alight by the heat of the engines. All 28 aboard would be the first to die on a burning airship, and with the war on the horizon, they would not be the last (Rose 151).
Most surprisingly, no specialized weapons were developed for the airships, which as bombers first carried 15 and 21cm artillery shells which were ejected from the airship over the target. These were used by the Army’s Zeppelins in the opening weeks of the war, but it soon became clear that these low flying airships were too vulnerable to groundfire to be of any real use (Robinson 86). This realization would push airship design evolution faster than any previous motivator. Among the first major new additions were the cruciform tail sections added to the M-Class airships. This feature had been pioneered by the rival Schuttz-Lanz airship company, and would markedly improve the handling and aerodynamics of the airship. Previously, Zeppelin’s had blunt tail sections, which were initially believed to be aerodynamically superior, but the taper on the newer models allowed for far better stability at speed. Enclosed gondolas were also added, being more or less essential for long patrols over the sea. Perhaps the most important of all was the introduction of duralumin on LZ 26 which enabled the construction of larger and stronger airship hulls (Robinson 89). The first airships to combine all of these features were the P-Class ships, which were very capable maritime patrol aircraft and were used on the first raids on London.
L12, a P-Class airship, the class would prove to be excellent naval patrol vessels and far more comfortable for their crews over the older, open gondola ships. (IWM)
As strategic bombers, the Zeppelins were ineffective. While at first they were surprisingly resilient to bullets and artillery splinters, the introduction of better training for anti aircraft crews and special phosphorus-core bullets for aircraft would see them fight a losing battle that would only end weeks before the war itself did. Zeppelins were built to fly ever higher to try and avoid these threats, and they flew their raids at night to try and avoid detection and artillery spotters. They would fail, but they would produce much more robust and versatile airships which remained very capable maritime patrol aircraft. The prime of these being the R-Class.
These ships entered service in 1916 with a host of new improvements. The new class did away with the long, inefficient cylindrical sections in favor of a teardrop shape which both reduced drag and vastly increased internal capacity. They were also the first to carry six engines, these being Maybach HSLu motors capable of producing 240Hp which gave them a trial speed of roughly 60 kilometers an hour. The hydrogen controls too were improved, with a responsive electric control system allowing for more precise and sensitive inputs, which were necessary when the airship operated at or above its maximum loaded ceiling of 3962 meters. In all, virtually every aspect of these ships had been improved (Robinson 120. Stahl 84-89). Unbeknownst to the German Navy, who were looking for better bombers to wage their ineffectual nightly war, Zeppelin had built a truly exceptional intercontinental aircraft.
The R-Class possessed a revolutionary teardrop hull shape, which vastly improved its aerodynamic qualities over the previous cylindrical forms. (Hauptkull)
On the night of July 26, 1917, Captain Ernst Lehmann set out on the longest patrol of the war thus far. With the standard R-Class airship, LZ 120, he patrolled the Baltic Sea for 101 hours. This ‘experiment’ was conducted with a considerable load of 1202 kilograms of bombs, 16918 kilograms of fuel, with a crew of 29. With his men divided into three watches, and running only three engines at a time, LZ 120 endured poor weather and successfully enacted engine repairs, all while dodging thunderstorms. When they returned to their base at Seerappen, the airship remained in good condition with enough fuel in its tanks for 14 more hours (Robinson 251, Stahl 89). As astounding as this feat was, it would soon be outdone.
In light of Lehmann’s record setting patrol, the German army now looked to the Zeppelin to undertake a truly groundbreaking mission. It seemed to all that General Lettow-Vorbeck’s troops, alone in Africa and low on supplies, were fighting on borrowed time. It was clear that the only way to reach them, and deliver vital supplies, was by airship. Thus a specially modified R-Class airship was prepared, L-59, which was lengthened and lightened to carry out the special mission. The 750 foot airship was to fly to Lettow-Vorbeck from Jamboli, Bulgaria, to the beleaguered general some 7000 kilometers away. It carried approximately 16,238 kilograms of cargo, and would be disassembled with its aluminum and fabric repurposed into radio towers and bandages. KorvettenKapitan Ludwig Bockholt set off from Jamboli on November 21, 1917 under strict radio silence. They passed through thunderstorms over the Mediterranean before crossing into North Africa, which would prove even more treacherous due to the updrafts which threw the ship about over the deserts. The heat too caused excessive hydrogen loss which had to be offset by dumping large amounts of ballast. They would cross the desert and receive a signal from Berlin, advising them to turn back as Lettow-Vorbeck’s forces had been defeated. In reality, the guerrilla general had pressed on into Portuguese Mozambique, where he had gathered the supplies he needed. Bockholt ordered the ship back with some arguments among the crew, and was back in Jamboli on November 25. In all his ship had been airborne for 95 hours and had traveled some 6760 kilometers, and upon its return still carried enough fuel for 64 hours more (Robinson 253-255, Stahl 90-91). Theoretically, L59 could have traveled to Chicago one way from Friedrichshafen, or potentially to New York and back.
The lengthened L59. (Hauptkull)
The rapid advancements in airship design during the war were incredible, though their use against civilians would leave a black mark which they could never truly wash away. England in particular bore deep scars as a result of the ‘baby-killers’, and as if to mark the end of an era, Zeppelin had passed away in March of 1917 at the age of 78. Despite the dark turn his invention had taken, many still viewed the count favorably, and in a May 1917 edition of the New York times he was placed as an equal alongside the Wright Brothers and praised for the years of dedication and disappointment he had spent honing his creation (Rose177). In the end, the war would cripple airship production and design in Germany, as the state was subsequently banned from operating large airships, and many of its Zeppelins were turned over to the Allies or destroyed by their crews. Many airship veterans, and even historians, would continue to state decades after the war, that the raids over England held down ‘a million men’ from being deployed to the continent. In reality, by June of 1918, Britain had exactly 6,136 men devoted to home air defense, and the total wartime damages from strategic bombing amounted to 1.5 million GBP. This compares rather poorly to the equivalent of 13.25 million GBP spent on airship construction, to say nothing of the hundreds of Gotha and Zeppelin Staaken biplane bombers built (Rose 173).
The Crossroads
Without their primary customer, and more or less totally banned from building their main product, the Zeppelin company was seemingly at the end of the line. Colsman, seeking to rapidly increase revenue, attempted to pivot the enterprise away from airships towards cars and consumer goods, regardless of the anger from the true believers in the firm. However, the economic crises that emerged in Germany after the war rendered the plan hopeless; there would one day be a market for luxury Maybach cars, but it was very far off.
A brief power struggle in the company ensued with Dr. Eckener becoming its head over the firebrand Captain Lehmann, who had taken part in destroying several Navy airships which were to be turned over to the Allies. Dr. Eckener found a loophole in the treaty which threatened to destroy the company; while Germany wasn’t allowed to possess an airship, the Versailles treaty did not explicitly prevent any private enterprise from building or operating airships of their own (Rose 194). With this in mind, Eckener approached Dürr and his engineers to design a new airship, one which could in no way be used for military purposes. Thus it seemed that DELAG was poised to return almost as suddenly as it had vanished back in 1914. Initially, there were plans for a trans-atlantic airliner based on a massive wartime X-class airship, but its proximity to a military design was too problematic, not to mention expensive. They accordingly settled on a small design with regional ambitions.
A model of LZ 120 is prepared for wind tunnel tests. (Wikimedia)
The design work for LZ-120 Bodensee, named for the lake from which the first Zeppelin’s flew, was completed on March 10, 1919 and first flew that August. Its design was the most efficient of any airship built up to that point, as despite being considerably shorter than the airliners that preceded it, at around 120 meters, it possessed an incredible useful lift of 44,678 kilograms and had a trial speed of 132 km/h, thanks to its four 245hp Maybach IVa motors. Perhaps most impressively of all, it could fly in all but the worst weather (Eckener 201). When fitted out for service, it was laid out in a manner similar to a passenger train within the combined cabin and control car. It possessed five compartments seating four, and one VIP cabin in the front who paid double fare. Six more seats could be fitted if the partitions were removed. As with the previous airliners the cabin was well furnished with a fine wood paneling over the structural elements and specially made aluminum and leather chairs for the passengers. At the rear of the gondola were the washroom and buffet (Robinson 258 Rose 196).
The small but quick Bodensee. (George Grantham)
When DELAG resumed service in the fall they began operating on fixed scheduling, which was made possible owing to Bodensee’s reliability and ability to fly through rain and wind. The sightseeing flights were done away with and replaced with a regular passenger route which ran from Friedrichshafen to Berlin with a stop in Munich. Generally speaking, the lax margins for luggage that existed in the pre-war DELAG were also done away with fees being added after 13 kilograms. On one occasion, a woman wearing extravagant furs brought nearly a dozen trunks aboard and tried to protest the fees which greatly exceeded that of the original ticket. In order to make up for slack during slow periods, mail was carried in place of passengers. Overall, Bodensee proved very effective, earning 500,000 marks in its first month, placing it on the road for long term profitability (Rose 196). Typical passengers were state officials, Zeppelin company personnel, and foreign visitors who could not depend on the rail network, which had been racked by strikes, coal shortages, and damaged infrastructure during the revolutions of that year.
Likely owing to tastes tempered by wartime hardships, Bodensee’s decor was subdued and looked to serve a more professional class, rather than the pleasure seekers of the Pre-war DELAG airships. (Bundesarchiv)
Eckener saw these routes as only the beginning and traveled with the airship to Stockholm in October. There he received an enthusiastic reception where he sold tickets for flights on the yet-to-be completed LZ 121 Nordstern. This was to be just the start, for the real destination for his airline was Spain. In the long term, however, his hope was in crossing the Atlantic. The Zeppelin’s long haul capabilities were well proven and shorter flights could be serviced by more modern planes, which by the mid 20’s could be flown with some semblance of safety and comfort. With long term plans seeming coming to fruition, DELAG completed the season’s operations in December, having flown on 88 out of 98 days for 532 hours, over 51,981 kilometers, and servicing 4,050 passengers. LZ 120 was placed in maintenance to be lengthened and have its control surfaces altered to compensate for its oversensitive yaw characteristics (Eckener 200, 201 Rose 198). However, these plans were not to be, as the loophole that allowed these operations was closed.
1919 was a chaotic year for most of Europe. In Germany, mass strikes of workers, and mutineers from the Army and Navy, launched a short-lived revolution in Germany after the Emperor fled and his government collapsed. (National Archives)
The Allied commission had ruled in January of 1920 that DELAG was not authorized to fly airships under the Versailles treaty, and they were instructed to turn their two airships over to France and Italy, who were to have received Navy Zeppelins that had been destroyed by their crews. Dr. Eckener would claim this was a protectionist ruling, given that the Allied commissioner, Air Commodore Masterman, was also in charge of Britain’s own flagging airship program. In any case, LZ 121 was christened Mediterranee in French service, and subsequently dismantled in roughly a year. Bodensee however, would spend many years in Italian service as the Esperia. While it never returned to regular passenger service, it made flights from time to time at numerous civil and military events from its shed in Ciampino near Rome. Most notably it accompanied the polar exploration airship N1 as it traveled to Barcelona, Spain, flew from Rome to Tripoli and back in 24 hours, and was shown to Japanese Crown Prince Hirohito during his visit in 1921. While most reparation airships were neglected and dismantled in the years following the Great War, Esperia seems to have been well maintained until it was decommissioned on July 18, 1928 (Robinson 350).
Esperia a few weeks before its decommissioning after nearly ten years of service. (Bundesarchiv)
With Bodensee and Nordstern out of their hands, Zeppelin seemed to be running on borrowed time once again.
The Zeppelin, Banned
Zeppelin was in trouble, but there would soon be an opportunity for them to get back on their feet. While the British airship program was largely dysfunctional, it had managed to garner interest in the technology. Their own R.34, which was largely a reverse engineered R-Class Zeppelin, had managed to cross the Atlantic, though with worrying slim margins for fuel. For the time being, the British built on this achievement with the pending sale of R.38 to the US, which subsequently was renamed ZR 2. Given American interest in the technology, Dr. Eckener offered to build the United States an airship to compensate them for the one which was promised to them under the Versailles treaty, but which its crews destroyed. The US Navy jumped at the offer and offered to pay 3.56 million gold marks for the airship, though they were stopped by Air Commodore Masterman who refused to allow the construction of the airship in Germany. This block would remain until the US Navy was preparing to receive the ZR 2.
While the British were able to replicate German airship technology, they understood it exceedingly poorly. R.38/ZR-2 was based on a high altitude airship design with a hull that was designed to be maneuvered only at high altitudes, as its beams were made thin to reduce weight. While ZR-2 was proceeding with its final trial flight, its hull shattered during a low altitude turn at 99 kilometers an hour and it exploded. Of its 42 crew and passengers, only 5 survived. The US Navy was outraged. They directly accused the British of protectionism with the intent to force them to purchase their dangerous aircraft, and in the maelstrom of backlash, the German airship ban was lifted. The US Navy and Dr. Eckener soon agreed to an airship specified to be only used for civilian purposes, and that Zeppelin would shift production to consumer goods after it would be completed. All involved knew that neither clause would be observed, but Masterman was forced to accept their terms regardless (Rose 221, 222).
The US Navy soon sent representatives to Friedrichshafen to oversee the design and production of LZ 126/ZR-3. The partnership between Zeppelin and the US Navy proved amicable in 1922, and eventually it was agreed to establish a US based entity for airship production, Goodyear-Zeppelin, the following year. Work on the new airship progressed as smoothly as one could have hoped during such difficult times.
LZ-6 is brought into the Lakehurst hangar for the first time. It was soon to be rechristened as the USS Los Angeles. (Wikimedia)
ZR-3 was launched in 1924, the large airship looking akin to a much larger, and stretched LZ 120. The airship was not merely a means of keeping the company afloat but to test the new technologies that could very well make trans-Atlantic air travel safe and reliable. Eckener himself flew ZR-3 out of Friedrichshafen on October 12, 1924, and despite some concerns about the airship’s maximum range, ZR-3 made the flight from Germany to the U.S. handily, despite running into a storm and encountering a headwind which slowed the ship down to 48 kilometers an hour. The airship flew over New York for several hours before proceeding to its shed at Lakehurst, New Jersey where it was met by a tremendous crowd. The ship would soon become the USS Los Angeles, and its success did more than save the company, it proved intercontinental air travel was more than achievable, it could be done safely and comfortably (eckener 27, 28).
The USS Los Angeles on parade over New York, joined by two US navy blimps, including the aluminum clad ZMC-2. (imgur)
ZR-3 also proved to be somewhat of a political litmus test. In the early Weimar period, its politics were especially volatile and Eckener had to brave these winds in order to accomplish anything. Whereas Count Zeppelin played the Imperial Court, Eckener faced liberals, conservatives, and political extremists of almost every variety. He did exceedingly well. The Zeppelin itself, a symbol of ‘the good old days’, played well with conservatives, liberals were satisfied with his ability to reinvent and grow the company in hard times, and the company’s large industrial workforce and generous benefits saw him receive congratulations from socialists and some communists. In terms of the far-right, he ranged from disinterest to outright hostility. Among the Nazis there was little interest in airships in general. Herman Goering, one of the movement’s leaders and former ace fighter pilot, saw airships as quaint and dated, with most in the party sharing his sentiments. Some members of even more extremist organizations claimed Eckener and Zeppelin had sold Germany out by giving ZR-3 to the US. Ultranationalists would go on to accuse the company of being controlled by a Jewish cabal and Eckener himself was the target of a young man with a rifle who had sworn to kill him, who was subsequently arrested (Rose 232). Eventually, some nationalists would be satisfied by Zeppelin’s all German operation and the ZR3 “controversy” would be left in the past. Despite this, the work at Zeppelin would proceed apace, especially as the German economy stabilized in the mid 20’s and many of the most dangerous fringe political groups had burnt out or had fallen out of public view, if only for the time being.
With a more or less stable political footing, and as the US Navy began to work their new airship into service, Dr. Eckener planned the next major step for Zeppelin.
The Graf
Eckener wanted an airship to build on the promise ZR-3 showed in its cross Atlantic outing. However, a roadblock appeared between Eckener and his new airliner, he hadn’t the money. The start-up capital to build and operate a new airship amounted to some 7 million marks, and to try and reach this figure he would attempt to repeat the miracle of Echterdingen. The press campaign began in July of 1925, and through donations and the sale of memorabilia, he was only able to amass 2.5 million marks, suitable enough for only the ship’s construction and nothing more. In short, the average German was far less secure in their finances, while the affluent noble class, once patrons of the old count, were gone (Rose 249). To make matters worse, airplanes had made significant strides in both safety and passenger capacity. Gone were the temperamental and fragile canvas and wooden biplanes, now in their place were solid plywood marvels like the Fokker F.VII and the all metal Junkers F.13, which rapidly took over intercity air travel during the mid 20’s.
Graf Zeppelin undergoing skinning in the Friedrichshafen hangar. (Zeppelin GMBH)
Regardless, Eckener pressed on, and between 1925 and 26 he gave nearly a hundred lectures on a press circuit which bolstered fundraising efforts. Once it was clear appeals to the public had reached their limit, he would make a personal request to President Paul Hindenburg, which brought a state contribution of 2 million more marks. The last of the money was found in selling assets from Zeppelin’s subsidiary companies (Eckener30, Rose 287). With the funds in hand, the design work was finalized with the new airship being what was, more or less, a larger derivative of LZ 126 with some cutting edge features. However, the new LZ 127 would not be the largest and most efficient airship the company was capable of building, but rather it was a proof of concept that would show that commercial, oceanic air travel was possible. While they had the funds for a new airship, they were still restricted by the size of their hangar at Friedrichshafen, which would prevent them from building airships much larger than the wartime X-Class for years to come.
Graf Zeppelin’s lounge prepared for dining service. (Yurigagarin-flickr)
By early 1927, LZ 127’s design work had been completed, and while built along the same lines as ZR3, it was fully furnished for passenger comfort. The combined gondola would contain the control and navigation facilities, along with the passengers rooms and amenities. The fore section contained the control room, a radio room, and a navigation room for use for the crew, and behind it was the kitchen, dining room and lounge, and passenger quarters. At the rear of the gondola were the stairs which led to the main crew quarters which contained mostly the same amenities, though with none of the fineries which existed below. The style of the passenger quarters evoked that of the famous and luxurious American Pullman railcars, though with some clever features. The passenger berths served dual purposes, by day they were lounges where passengers could take meals and relax in private, and by night they could be converted to a two bunk cabin.
Each 2 person passenger berth could be converted into a lounge during the day. (Zeppelin GMBH)
While LZ-127 could mostly be described as an enlarged version of the company’s previous airship, it did feature a number of innovations. Chief among these were its new Maybach VL2 engines, which in addition to producing a respectable 530PS, were multifuel engines that could run on either gasoline or Blaugas. The former was a fuel specially designed for airship use, as it possessed a density very close to air and could be stored in its own gas cells below the hydrogen. This enabled them to cut weight and conserve ballast hydrogen over long trips, as unlike gasoline, when the Blaugas was burned it did not significantly alter the weight of the airship and did not require the venting of hydrogen to regain equilibrium. Gasoline usage was kept to a minimum and would typically be reserved for takeoffs. Despite much of the design being brought over from a previous project, the airship was far better equipped for long flights. Its 37 tons of Blaugas could provide fuel for around 100 hours of flight, with a similar weight of gasoline providing only 67 hours (Rose 289).
Graf Zeppelin was built to the widest diameter that could be accommodated by the wartime hangar at Friedrichshafen. (Zeppelin GMBH)
The airship was completed in early July 1928, it being brought into service on the 8th and named Graf Zeppelin, in honor of the late Count. Shortly after a series of shorter test flights, Eckener arranged for a thirty six hour endurance flight across Germany on September 18th. The original course took the ship over Leipzig, Dresden and Berlin, before proceeding to Hamburg to practice oceanic navigation at night over the North Sea. However, the low cloud cover would have prevented the public from seeing the airship along that route and so they diverted to Frankfurt and Mainz before heading on to Cologne and Dusseldorf before reaching the North Sea via the Rhine valley. As was the case so many years ago, they were met by massive crowds as they passed these cities before finally heading out to sea. On the next day their course home took them over Hamburg, Kiel, and Berlin before they proceeded south back to Friedrichshafen (Eckener 32). However, not all were pleased. During further flights in October, French authorities protested the flight over the politically contentious Rhine territories, and subsequently provided directions for the use of airships over their own territory, forcing LZ 127 to fly at night and away from any military installations. The airship’s flight over southern England would also prove rather unsettling to those living there as it brought up unpleasant memories, and the airship would only rarely travel to Britain thereafter (Rose 289).
Graf Zeppelin over Berlin’s city palace during its first overflight of the city. (Bundesarchive)
These early flights would prove extremely promising, the only major issues which arose were political in nature, and the airship itself proved superb. Naturally, Eckener pushed for a flight to Lakehurst, New Jersey.
To Lakehurst
Eckener was prepared to fulfill the promise long dreamed of since the invention of the balloon and kindled during DELAGs best years, he was going to prove air travel could deliver passengers anywhere across the world. 40 crewmen and 20 passengers were assembled for the flight, though few paid for their tickets as they were mostly there to drum up publicity. This included journalist Lady Drummond-Hay, who had come on behalf of the media mogul William Randolph Hearst, who had exclusive reporting rights in the US for the voyage. One of the four who did pay the small fortune of $3000 for a ticket was one Frederick Gilfillan, an American financier who had a plane crash and two shipwrecks under his belt (Rose 295). To add to the foreboding, the weather reports were bleak. Storms and strong winds pervaded most of the approach to New York and numerous older steamships were in distress, while more modern liners were reporting considerable delays to their arrival (Eckener 34).
Eckener took the airship out of Wilhelmshaven on October 11, 1928, opting for a longer, but hopefully calmer Southern approach. The other captains, Fleming and Schiller, agreed to take a course South to the Mediterranean via the Alps, then to Gibraltar, followed by the Azores, and finally proceeding across the Atlantic to the airfield at Lakehurst. This earliest section of the voyage proved the most enjoyable as passengers and crew overflew the scenic Northern Mediterranean with largely agreeable weather. This however, was not to last. As after they flew west off the Azores, they ran into a storm front, and in the midst of exchanging the deck crew for the most experienced members, the nose dipped. Pots and pans clattered to the floor, the breakfast table settings slid from the cloth, and thunder rang out. While the crew remained in control through the rough weather, the passengers were no less terrified (Eckener 39). However, more shockingly, the crew would discover a wide swath of fabric had been torn from the lower port elevator and stabilizing fin, and threatened to jam the controls. By the time this was recognized, the Graf Zeppelin was in the middle of the Atlantic and three days from US navy assistance. After Eckener reported the incident to the Navy, he dispatched a repair team, which included his own son, and informed the passengers of the situation.
The repair team luckily found the damage to be less threatening than they had worried, and that they would be able to reattach the third of fabric that had remained , while cutting away the fluttering edges. The repairmen wore safety tethers while they clung to the outside of the airship and endured the roughly 80 kilometer an hour slipstream as the ship bobbed up and down as the control crew compensated for the increase in weight brought on by the rain. The repair crew worked for around five hours until the ship could rely on the fin once more (Eckener 41).
The result of the storm damage. (Wikimedia)
While the ship was no longer in danger, the new problem became boredom and discomfort. Safety precautions prevented the kitchen from using its electric stoves, lukewarm coffee was served in glasses, as all the china cups had broken in the morning, and, perhaps most distressingly, the beer and wine had run out. The passengers, with the exception of Lady Drummond-Hay who brought plenty of warm clothes, learned just how chilly the Atlantic could get, as the airship had little insulation. Though, the passengers discomfort was eclipsed by the elation of the crowd that gathered to see the ship as it flew over Washington DC, Baltimore, and Philadelphia before it went on to New York. This would prove prudent, as it showed the public that despite the damage it had taken, it was in no danger and capable of traveling wherever its crew saw fit (Rose 299, Eckener 43).
The discomfort of many of the passengers was quickly overshadowed by the Graf Zeppelin’s arrival at Lakehurst. Some 150,000 people had traveled to Lakehurst, where they were policed only by some 76 marines, 50 sailors, and 40 state troopers. While Eckener received congratulations from President Hindenburg via telegram, he embarked on a number of press ventures and all manner of celebratory events in New York. All the while, he was kept informed of the repairs being made to the airship, which would take 12 days and delay their return to Freidrichshafen until October 28.
Graf Zeppelin often shared the Lakehurst hangar with the USS Los Angeles during its visits to New York. (Wikimedia)
In all, the trip was successful but with mixed results. On a financial basis, the trip was successful in that it was profitable going one way. The operating costs were judged at $54,000 one way, with cargo and passenger revenues bringing in roughly $70,000; beyond that were the press deals which saw Zeppelin receive some $83,000, though these were likely to be considerably reduced for a regular commercial route. Eckener would claim a profit of $100,000, which considering the one million plus price of the airship, meant long term profitability was feasible.
The performance of the airship in the press was seen as both groundbreaking, yet unimpressive. From Germany to the US, the cross Atlantic voyage took some 111 hours, which actually compared poorly to the world’s fastest ocean liner, RMS Mauretania, which managed the crossing in 107. However this would be dispelled when Graf Zeppelin made the return trip in better weather, without detours, and arrived 72 hours later (Rose 301). Passenger comforts too were an issue compared with the ocean liner, though with a larger liquor cabinet and a gramophone with an ample selection of records, things were markedly improved on subsequent voyages.
Chief of all were safety concerns, as despite the airship being capable of handling the storm and subsequent damage better than any plane, it was still extremely concerning to any serious customer base. There was however, one feat which could allay these concerns for good, a world tour. However with the winter fast approaching, such a trip would be put off until a more favorable season.
Egypt Bound
The Graf Zeppelin would fly twice across the Mediterranean, visiting many of its most ancient landmarks (bsmith2123)
While a world tour was not feasible for several more months, a trip eastward was planned to raise publicity and bring in much needed capital. To promote the airship, a number of high level government officials and members of the press were invited. The choice of location would be Eastern Mediterranean, and much like the pre-war DELAG flights, the emphasis was on sightseeing. A particularly frigid winter would delay the flight four weeks until March 21, 1929, whereafter the Graf Zeppelin flew to a more hospitable region. It made its way down the French Riviera, after which it passed over Corsica and Elba on its way to Italy.
As they over flew Rome, with its ancient and modern sights alike, they sent a telegram to the head of Italy, Benito Mussolini. “Filled with admiration as we look down on Eternal Rome with its timeless remembrance of a glorious past, and its lively activity as a flourishing modern metropolis, we respectfully send our greetings and our good wishes to the genius of this splendid city.” Eckener would derisively say that he wondered if Mussolini would believe himself to be the “genius” of the city. The response would read “Many thanks for your friendly greeting! I wish you a happy journey. Mussolini.” (Eckener 59). From Rome it was on to Napoli, then Eastward across the sea to the Isle of Crete. Their arrival in the Eastern Mediterranean came with the end of the chill that had followed them since their departure from Friedrichshaven. With the last of the coats coming off, the airship made its way to Tel Aviv, and on to Jerusalem with the ship spending the night above the Dead Sea.
Graf Zeppelin over Jerusalem. (The Atlantic)
Unfortunately, the Graf Zeppelin was denied passage over Egypt by the British Foreign Office. This was likely because they wished to be the first with their own airships, which in a few years time were to fly from England, to Egypt, and then on to India. Eckener would be forced to tell King Fuad of Egypt that the weather prevented any landing there. However in 1930, the Graf Zeppelin would repeat this flight and would carry aboard a number of distinguished Egyptian passengers who were flown over the Pyramids and north, over the coast to Palestine.
During the first flight however, the airship overflew the coasts before heading Northward to Greece. They reached Athens at 6 am, there flying over the ancient Acropolis and then on to Mount Olympus. The planned overflights of Romania and Istanbul were canceled after deep cloud cover was reported over much of the region, and thus they returned to Athens, to the enthusiasm of those who slept through the airship’s first visit. From there it was West to Corinth before making the return trip to Friedrichshaven. The route home was to be over the Dinaric Alps, on to Pressburg and Vienna, before heading west and home. Apart from some passes through narrow clearings, and a blizzard which came on as they passed over Vienna, the return trip was uneventful. In fact, Eckener himself was glad for the poor weather as he was able to impress upon his passengers the safety of the airship and its ability to handle the elements (Eckener 65).
The Egypt flight of 1929 would prove an incredible and undeniable success in comparison to the admittedly rough Atlantic voyage. In addition to the views of some of the most ancient sites across the region, there were no hiccups in regards to lapses in comfort or entertainment, as the ship passed over the less exciting spaces in the dead of night. Perhaps most importantly of all, the ship’s reliability shone through with no major mechanical issues being reported during the flight.
Around the World
A postcard illustrating the course of the world voyage. (The Atlantic)
With the sight seeing trip behind him, Eckener now had the ideal Autumn weather to prove once and for all the safety and reliability of his airships. The route was largely predetermined as the Graf Zeppelin would need to stop at suitably sized hangers to take on new supplies and undergo any serious maintenance should trouble arise. The ship could take on fuel, ballast, and hydrogen at a simple airship tether, but there it would also be at the mercy of the weather. As such, Graf Zeppelin would fly East over the Soviet Union and make a brief appearance in Moscow, then proceed to Kasumigaura Air Base near Tokyo, where a former wartime zeppelin shed had been transferred and rebuilt. From there it was across the Pacific to America, then to Lakehurst outside of New York, and home again after crossing the Atlantic. However, a wrinkle formed in this plan when William Randolph Hearst, who would pay $100,000 for exclusive media rights in the US and Britain, requested that Eckener begin the journey from Lakehurst. His deal covered a good amount of the overall operating expenses of the trip, valued at around $225,000, much of the sum being spent on shipping 25,003 cubic meters of blau gas to Tokyo. Eckener’s solution was simple: fly Graf Zeppelin to Lakehurst, announce the voyage to the English speaking press there, and then fly back to Friedrichshaven and announce it again to the German press. In doing so he placated Hearst and the more nationalist elements within his own country.
The rest of the expenses were largely paid through passenger and mail fares, though again, few bought their own tickets. The overwhelming majority of passengers were there on behalf of newspapers and a variety of media groups whose focus was on travel, though a single ticket could cost upwards of $2,500. Beyond that was a hefty $50,000 gained through German media deals, and a number of limited postage stamp sets which sold very well among collectors. Despite the record setting nature of the flight, it was to bring in some $40,000 after covering the considerable supply hurdles (Eckener 68, 69).
The Graf Zeppelin departed for Lakehurst on August 1, 1929. This was to be a fairly unremarkable flight save for its two special passengers, Sue, a baby gorilla, and Louis, a chimpanzee, who were being brought to their new home in the US. 95 hours later, they were in Lakehurst and the true voyage began (Rose 307). Graf Zeppelin would return to Friedrichshafen after an overflight of Paris. The trip so far would prove to have a markedly different atmosphere, as in addition to the card games, conversations, and the record player, which often hosted Eckener’s own collection of Beethoven and Mozart, the air was busy with the clatter of the reporter’s typewriters.
The airship would spend five days in Friedrichshafen preparing for the journey ahead, which was to cover some 20,116 kilometers. During the layover, a number of new passengers boarded including Commander Rosendahl of the US Navy, Professor Karlkin, a Soviet meteorologist, and Commander Fuiyoshi of the Imperial Japanese Navy who was accompanied by two members of the Japanese press. With a crew of 41, and 20 passengers on board, Graf Zeppelin flew east (Eckener 72, Robinson 272).
A post card depiction of Graf Zeppelin leaving Friedrichshafen after the second “start” of the voyage. (German Postal History-Stampcircuit)
Now prepared for the flight ahead, they departed and flew north east over East Prussia and the Baltics. The approach to Moscow saw the trip’s first real challenge, a low pressure area developed north of the Caspian sea and was moving north. This would create strong headwinds along the original route and could potentially strain the airship’s fuel supply, however if they chose to fly on a more northerly course they would have a favorable westerly wind. To the anger of the Soviet representative, and to the disappointment of the crowds that had gathered in Moscow, Graf Zeppelin flew north. Upon flying past the city of Perm and past the Ural mountains, it quickly became clear why they had to bypass Moscow. The immensity of the far east would have proven disastrous had they run out of fuel, it was a land which was mostly untouched and beyond human civilization. Regardless, the frustrated Soviet Press devoted a good deal of energy criticizing Eckener and leveling a number of conspiratorial allegations at his decision (Rose 309).
Beyond Central Russia was the expansive taiga which Eckener described, “Like an extraordinary, decorative carpet it blazed up at us in all its colors-green, yellow, blue, red, and orange-horribly beautiful when we thought we might have to land on this carpet and be trapped helpless and lost amid the swamps and countless criss-crossing little streams” (Eckener 75). Navigation here and across Northern Asia would prove difficult owing to the few landmarks, even the smallest villages were noted and used to chart a course, the smallest being made up of a number of tents. Among the many incredible sights on those northern latitudes were the distant villages of the Yakut people and the aurora borealis which shone over the horizon. As they neared edge of Siberia they visited the city of Yakutsk, where they dropped a wreath over the cemetery where German prisoners of the Great War were buried. From there they proceeded to the sea of Okhotsk where their trek through Siberia ended (Eckener 76-81).
Graf Zeppelin reached Hokkaido, Japan at dawn, and with good weather proceeded southward on to the Japanese mainland. The airship overflew Tokyo for some time and performed a series of maneuvers over Yokohama Harbor above the massed onlookers. When they came in to land at Kasumigaura, they were met by an immense crowd, as thousands had traveled across the country to see the airship.
A commemorative wood block print of the Zeppelin’s visit to Japan. (The Tokyo Files)
While the airship was impressive to crowds on both sides of the Atlantic, it hardly compared to the fanfare it received in Japan. While Graf Zeppelin shaved roughly two days off the next fastest way across the Atlantic, it had bridged Japan and Europe in less than four. The next fastest, and still rather exclusive method, the Trans-Siberian Railway, took two weeks. Otherwise, by fast steamer, it took nearly month. One local newspaper would claim the trip as one of mankind’s finest achievements, and the event would receive more column space than any other event in Japanese history until that point. Those aboard the airship would spend six days in Tokyo, with key members of the crew being invited to a series of events hosted by the Japanese government. Eckener and his officers would attend a lavish state banquet at Tokyo’s grandest hotel along with Japan’s highest ranking ministers and the Chief Admiral of the Navy. This however, could not compare to Eckener joining Emperor Hirohito for tea at the Imperial palace, after which he was presented with a pair of silver cups, a ceremonial sword and dagger, silk embroideries, and porcelain vases. The stay in Japan culminated in the entire crew having afternoon tea at the German embassy, with nearly every German in Japan being in attendance (Eckener 83, Robinson 273, Rose 309).
Graf Zeppelin over Yokohama Harbor. (Old Tokyo)
With their stay over, the crew prepared for the flight across the Pacific, though an accident in removing the airship from its hangar resulted in a delay until the following morning on August 23, 1929. The airship would depart minus its Soviet representative, and its Japanese contingent would be rotated out for Naval representatives Lt. Commander Ryunoske Kusaka, Major Shibata, and a reporter. The journey across the Pacific was fairly unremarkable apart from the distance traveled, and the views were often obscured by clouds and fog. Graf Zeppelin reached San Francisco on the early morning of August 25 where it was greeted by a number of airplanes and ships which had come out of the harbor to meet it. They then proceeded South to Los Angeles where it would land at Mines Field, the airship arrived late at night and went largely unseen, save for those who traveled to see it the following morning. Interestingly, the landing was made difficult due to a low altitude temperature inversion which required they valve off hydrogen as the denser layer of air otherwise prevented the ship from descending (Robinson 273). This effect is partially responsible for the region’s agreeable climate, and its smog.
The airship was greeted by half a dozen or so aviators as it reached San Francisco. (SADSM)
Unlike Tokyo, the stay would not be a long one, and after an evening with Mr. Hearst, whose massive mansion was in Los Angeles, the airship was preparing to leave again. However, upon trying to leave they were short on hydrogen and were forced to proceed at very low altitude with very little ballast, southward around the Rocky Mountains. Initially, it flew so low that it nearly struck power lines as it departed the airfield. From San Diego they traveled through New Mexico and, like the crew of the L 59 almost ten years earlier, experienced extreme updrafts which could drag the ship over a 300 meters upward. Eckener considered this the most difficult point in the journey, and he believed the region made traversing America by airship a serious gamble should one wish to travel from coast to coast. Apart from the Texas homesteader who took potshots at the airship, the flight proceeded smoothly after they reached El Paso, after which they swung north on a course that would take them over Kansas before reaching Chicago. While the airship was greeted by crowds wherever it went, Chicago’s excitement rivaled San Francisco’s as a handful of planes joined it in the air and massive crowds cluttered the roads and gathered in parks to see the airship overfly their city. On its departure, it visited the Goodyear-Zeppelin headquarters at Akron Ohio before making its way to New York to complete the journey (Eckener 90).
Chicago matched San Francisco’s excitement as Graf Zeppelin was greeted by planes, crowds, and caused massive traffic jams. (RareHistoricalPhotos)
The world flight was completed when Graf Zeppelin returned to the hangar at Lakehurst on August 27, 1929. While the airship had visited the city several times before, its reception on that date surpassed all the rest. On that day New Yorkers shredded more phone books for confetti than ever before, and after a massive reception at city hall, Eckener was invited to a meeting with President Hoover. There Hoover would tell him “I thought that the day of the great adventurers, like Columbus, Vasco de Gama, and Magellan, was in the past. Now such an adventurer is in my presence. I am happy, Dr. Eckener, that the American people have greeted you so warmly, and today would like to extend my personal good wishes for your enterprise.” (Eckener 93, 94)
Graf Zeppelin had made the 11,104 kilometers from Friedrichshafen to Tokyo in 102 hours, had crossed the 8851 of the Pacific in 79, and crossed the 5,632 of America in 52 (Rose 314). All of these were new records, and the lack of any major mishap would prove beyond a shadow of a doubt the safety and reliability of Eckener’s airship. With it completed it seemed it would be simple enough to begin a regular passenger service, though this was not to be. A massive stock market crash in the US in just a month’s time would spill over and leave the entire world economy in shambles, aviation in particular would be hit hard. All but the largest aircraft manufacturers were out of business, and what few fledging airlines existed were hit equally as hard.
The Desert and the Future
With the world in the grips of an economic catastrophe, Eckener had to redress his plans. Further airship construction would need to be put on hold and new streams of capital would need to be established. The admittedly lackluster successor to Graf Zeppelin, LZ 128, was canceled. With its cancellation also went the hope of a triangle airline scheme by which DELAG was to sell tickets which granted passengers access to North and South America and Germany. However, Graf Zeppelin completed a trial run with a complement of paying passengers and freight in 1930, flying from Friedrichshafen to Recife Brazil, and then to Lakehurst. It proved impractical, as the volatile and unpredictable North Atlantic weather made comfortable passenger travel impossible without a specially designed airship. While no additional triangle flights were conducted with Graf Zeppelin for some time, it made a profit of over $100,000. Owing to having only 11 passengers aboard, air mail and stamp sets made up most of the earnings (Rose 350).
Graf Zeppelin at Cardington field with the British airship R-100. (Fineart America)
In 1930 Graf Zeppelin made a number of publicity flights across the UK where tickets were offered for short sightseeing flights. By this point the British aversion to the Zeppelin had clearly run its course, perhaps this can be seen no clearer than when the Graf Zeppelin overflew Wembley Stadium during the FA Cup. Beyond this the Egyptian tour was revisited again, and with the tragic demise of the British Imperial Airship scheme after the crash of R-101, Zeppelins were allowed full reign over the region.
Graf Zeppelin would finally dispel Britain’s phobias during its English visit, here overflying Wembley Stadium during the FA cup. (Wolves)
In the meantime, Graf Zeppelin was hired out to complete a scientific survey of the North Pole in 1931. Without passenger fare, reporting rights and stamp sets would bring in most of the profits. Incredible concerns were raised over the Arctic weather and icing, which could disturb the airship’s equilibrium. Despite being seriously damaged by a hail storm, Graf Zeppelin completed the survey along with the Soviet icebreaker, Malygin.
Zeppelin survived these financially tumultuous years by very narrow margins, and oddly enough, was kept afloat by stamp collectors who drove up the price of the limited edition sets the company commissioned. However, in 1931, there were bright spots on the horizon for DELAG. Graf Zeppelin was to begin a regular international service to South America, and a new airship was being developed for cross Atlantic service.
Regular Service to South America
The airship landing field at Recife, Brazil. (picryl)
While regular triangle passenger flights between the three continents were well beyond the capabilities for Graf Zeppelin, it could chart a service to South America with ease. While the North Atlantic was frigid and temperamental, and had previously proven extremely uncomfortable for passengers, the tropical and relatively warm waters of the South were ideal. After the Arctic flight, three passenger flights to South America were conducted in the late summer and autumn of 1931. These early flights were fairly limited, after leaving Friedrichshafen they proceeded over Southern France, Spain, the South Atlantic, and arrived in Recife, Brazil where an airship mast allowed them to service their vessel. This sole mast and its fairly remote location required DELAG to partner with the German Condor Airline to service other major cities across South America (Robinson 279). In spite of this, these initial flights would prove so successful, that all publicity flights were terminated so that all efforts could be taken to focus on the South American line.
Graf Zeppelin’s groundbreaking South American trips were the first of their kind, and were refined over the coming years into a regularly scheduled route. (Hapag Lloyd)
The following year would see nine passenger flights, the last three of which saw the airship fly down to Rio de Janeiro in order to draw interest to build a hangar there. Beyond this the flights were improved in the choice of view. When the airship departed or returned to Europe, it often did so through the French Rhone Valley and over the Bay of Biscay, or it proceeded south over Spain and then to the Cape Verde Islands off of Africa. Occasionally, there were also scheduled stopovers in Barcelona and Seville, where the excellent weather often permitted the airship to remain outdoors for sometime (Robinson 280). While the 1931 flights were more or less experimental, those of the following year were routine, all of which sold out, and beyond ticket sales the revenue from freight and mail was not inconsiderable (Ecekener 115).
As successful as these flights were, they were overshadowed by events in Germany. The Nazis were gaining greater prominence, with the regime exerting an ever more dominating force over the country, though Zeppelin and DELAG remained independent for the moment. In the backdrop of such developments, Eckener was able to see that the Rio hangar was built. The year would see another nine trips, the last being a triangle flight that would take the airship to the 1933 Chicago World’s Fair.
By the summer of 1933, the aviation authorities in Germany required all registered aircraft to display the Nazi swastika. The Graf had swastikas painted on the port side of its vertical stabilizers, the other emblazoned with the older Imperial style flag. Displeased with having to carry the symbol, Eckener flew the airship around Chicago on a clockwise course which hid the swastikas from crowds. He was, however, unable to prevent it being photographed by circling planes, with the subsequent images being printed in newspapers images world wide. This would not be the first time he attempted to act against the new regime. Prior to this, he forbade the Nazis from holding events at the new massive hangar at Freidrichshafen (Rose 357, 364). These marked the first in a number of protests Eckener had against Nazi propaganda minister Josef Goebbels, who wished to use the Zeppelins to carry the flag of the new regime. Beyond this, Goebbels often took to chartering the airship for political events and publicity flights, much to the annoyance and displeasure of Eckener and many airship crewmen who hated the politics of the new regime and saw these “circus flights” as a waste of time.
In spite of the ongoing feud, DELAG continued to improve its services to South America. Graf Zeppelin flew twelve round trips to South America in 1934, the third flying as far as Buenos Aires where Eckener unsuccessfully tried to convince the Argentinian government to build an airship hangar. Buenos Aires was to be a major hub for DELAG, as it was hoped that they would be able to make sales amongst the sizable German enclave there. However this was not to be, and instead they bolstered their partnership with the Condor Airline which could fly the airship’s passengers from Rio de Janeiro by seaplane.
Graf Zeppelin’s overflight of Buenos Aires wasn’t enough to convince the Argentinian government to help finance an airship hangar there. (Wikimedia)
The political environment became more contentious during this time, as Goebbels’ propaganda ministry and Goering’s Air ministry began to feud over the airships. Both offices devoted large sums to the production of LZ 129 and chartered increasing usage of Graf Zeppelin. Despite his long standing personal disinterest in the airship, Herman Goering recognized it as an important and internationally recognized symbol of German aviation. A symbol which he knew improved the standing of his new office, in contrast with Goebbels ideological zeal. In any case, both men knew they could force Eckener’s cooperation through the resources they devoted to his company, despite what trouble he would occasionally cause them.
The year 1935 would continue to see a business boom for the Brazil route, and saw 16 round trip flights across the Atlantic. There was also considerable growth in passenger travel which peaked in that year at 720 with an additional 14,061 kilograms of freight carried, including some 900,000 letters (Eckener 116). In short, DELAG had pioneered the international airline just as it had in 1919 when it achieved regular air service with Bodensee. However, just as it had been in 1919, DELAG would be dissolved again.
Political Troubles and the End
LZ-129 Hindenburg comes in to land at the airship hangar outside of Rio De Janeiro, here the two airships alternated on the South American route until the loss of Hindenburg at Lakehurst. (Wikimedia)
Just as DELAG was honing its international air service, it was dissolved. Air Minister Goering would reorganize most German airlines, and he would visit this on DELAG on March 25, 1935. The new Deutsche Zeppelin Reederei (DZR), or German Zeppelin Shipping Company, would take its place, this new entity being state owned. In doing so, Goering would have final say on airship use, largely putting an end to the quiet feud with Goebbels.
With this change came a transfer of command, Eckener was replaced with Lehmann, of Great War fame. Lehmann was an able commander and fiercely nationalistic, which made him a far more palatable choice over the decidedly liberal and world trotting Eckener. The former became chairman of the Board of Directors and still held some influence, but his control over the airline and the Zeppelin company, which he still presided over, slackened. Eckener continued to work for the airline in order to ensure safe operations, and to do his best to keep the Nazis from becoming too intertwined with the business. Initially, he was successful, as LZ 129 entered service to become the second airship on the South American route, after he had first flown it to the United States. Its name too, Hindenburg, was chosen for its lack of ties to the new regime.
This state of affairs was not to last as the political tides grew more volatile. As a result of Ecekener’s open and continued complaints about Goebbels’ use of the airships, the Reichsminister would issue an order to remove all mention of Eckener in any future news publications. This would backfire spectacularly when President FDR assumed and looked forward to Eckener being the captain of the Hindenburg on its first Atlantic voyage to the United States. Rather than admit a blunder on the world stage, the publication moratorium was lifted temporarily, with Goering subsequently intervening between the two and meeting with Hitler to have the moratorium lifted entirely (Rose 393, 395). In any case, and in spite of his own convictions, Eckener’s work would continue to benefit the Nazis and he would continue to stay, and work in Germany.
The final straw came a year later in 1937, when Hindenburg caught fire over Lakehurst in the most infamous airship disaster. While accidents were common in air travel at this point, never had one so spectacular been caught on film and so publicized. In spite of DELAG never having lost a passenger in its decades of operation, passenger airship travel would end there. As a result of a flashy landing stunt to bring the airship in quickly, Captain Lehman overstressed one of the rear structural rings and snapped a bracing wire. The wire tore a hydrogen cell, and a static discharge ignited the air mixture near an aft ventilation shaft (Rose 440, Eckener 173). Following the accident, what interest the state and public had in the airships quickly dissipated, and Graf Zeppelin, after nearly ten years in the air, was decommissioned and later dismantled. Eckener himself would largely go into retirement, though on paper he remained a key figure at Zeppelin and some of its subsidiaries.
Conclusion
The Graf Zeppelin coming in to land at an airport in Basel, Switzerland. (TagesWoche)
The airships built by Count Zeppelin and the airlines which operated them can be said to be among the most groundbreaking endeavors in the history of aviation. In terms of long range aviation, many of their efforts would outpace their competitors for upwards of a decade. In regards to air travel, nearly every major milestone was achieved first using their airships. DELAG would be the first to pioneer passenger air travel, establish regular, scheduled transportation flights, and build the first transcontinental airline. While the passenger airship was dealt a fatal blow with the destruction of the Hindenburg under the DZR, ironically, few endeavors can claim to have done so much with so few injuries as the DELAG airline.
Advanced Technical Descriptions
LZ 1-1900
LZ 1 prepares to depart. (Zeppelin The Story of a Great Achievement)
LZ 1 had a symmetrical, cylindrical hull formed from 16 transverse, wire braced, rings composed of 24 polygons that were connected by 24 longitudinal beams. The rings were spaced 7.98 m apart, save for those around the two control gondolas, which were 4 meters apart. The hull was made from unalloyed aluminum, and thus was very soft and contributed to the airship’s structural issues. The beams, which comprised the hull were practically openwork I-beams and offered little resistance to compression or bending loads, resulting in the center hull bending downwards during its test flights. The hull measured in at a length of 128 m with a diameter of 11.74 m. (robinson 23)
There were 17 cylindrical hydrogen cells made from rubberized cotton. This material was composed of thin laminated sheets of lightweight cotton and rubber. Each cell was fitted with a relief valve, with 5 being fitted with control valves which allowed the crew to adjust for lift. The airship was covered in cotton treated with pegamoid to reduce drag and friction within the hull. Pegamoid was also used as a basic waterproofing material, its use was continued on Zeppelin’s until more suitable doping materials were employed during WWI.
The airship lacked large control surfaces, there being only a small pair of rudders above and below the nose, and a rear set which were connected to the sides of the hull. Pitch was changed by means of a 100 kg lead weight that was moved along the rail between the gondolas. This proved to be a very cumbersome and unreliable system, with the weight jamming on at least one occasion.
The diminutive Daimler engine and its bevel gear arrangement. (Wikimedia)
LZ 1 was controlled from two cars along the underside of the airship. These were both made of aluminum and designed to float in case of emergency. These were connected via metal piping which served to act as a walkway. Each carried a Daimler 4 cylinder engine which produced 14.2 horsepower at 680 rpm, with a weight of 385 kilograms. These each drove a pair of propellers on the upper hull above the cars, which they were connected to via bevel gears and shafts. These turned at a maximum RPM of 1200, considerably faster than the engine, in order to follow one of the Count’s theories. He would later find large diameter propellers operated at lower RPMs to be more efficient. The propellers themselves were made of simple flat sheets of aluminum and had four blades with a diameter of 1.22 meters(Robinson 24, Eckener 191).
Golden Years Airliners 1911-1914
LZ 10 Schwaben-1911
Crews gather to maneuver Schwaben after it lands (Stampcity)
LZ 10 Schwaben was the first specially designed airliner and almost fully divorced from the LZ 3 derivative airships. It was shorter and carried less hydrogen than the initial, and very unsuccessful Deutschland, but was far more efficient. The framework was made of a strengthened aluminum alloy, and used the tried and tested triangular girders that Dürr developed for airship use. The hull was 140.2 long and 14 m in diameter, containing 17 rubberized cotton hydrogen cells. This would be the last Zeppelin airship to use them, as they constituted a fire hazard and were responsible for the loss of this airship.
The Maybach C-X was the major success of the firm, which would go on to produce a number of specially designed aircraft engines. (Smithsonian)
Schwaben was powered exclusively by three 6 cylinder inline Maybach C-X engines, these being developed specifically for airship use. Each engine provided up to 145 horsepower and weighed 652kg. These water cooled motors had a displacement of 20.5L, and had a bore and stroke of 160 mm x 170 mm. Overall, they measured 129.5 x 182.9 x 86.4cm (Smithsonian). The forward engine was coupled to a pair of two bladed hard aluminum propellers, with the rear two being coupled to a pair of four bladed propellers. The rear propellers were a pair of two bladed propellers affixed to one another on the same drive shaft. They could propel the airship to a trial speed of 76.6 km/h.
The airship was controlled from the forward car which contained one of the three engines. Controls were improved as all the control surfaces had been moved aft, with the rudders and elevators being installed in a box like configuration at the rear of the airship. Ballast bags were installed fore and aft.
As with all DELAG airships, it did not lack for amenities and comforts. The passengers were seated in a gallery amidships. This compartment was composed of an outer frame sheet aluminum with inner wood supports and decorative framing. The inner compartment was covered in wood paneling that consisted of high layer plywood covered in mahogany sheeting. Pillars and decorative elements were decorated with mother of pearl inlays and the floors were carpeted. Ahead of the gallery was a small space for the attendant and an ice box with an accompanying liquor cabinet. To the rear of the gallery was a lavatory with a latrine made from aluminum fittings to save weight. The entire compartment was affixed to the hull with reinforced aluminum girders and cables.
LZ 11 Viktoria Luise & LZ 13 Hansa- 1911&1912
Viktoria Luise drops a line to its ground crew (this day in aviation).
These two airships were built roughly to the same specifications though Hansa was the heavier of the two owing to some minor difference in construction. These were very similar to the Schwaben in their overall layout, though they differed markedly in that they used goldbeater skins in place of rubberized cotton for their hydrogen cells. This material was a finely woven cotton fabric laminated with chemically treated sheets of cow intestine. It proved to be both lighter and could not accumulate a dangerous static charge and was used on all subsequent airships (Chollet 6).
The two also featured a crude cruciform tail section, from which the elevators and rudders hung. These were smaller than those mounted on Schwaben, but were no less effective. These evidently reduced drag considerably, as despite being 7.90 meters longer than Schwaben, both airships made for a trial speed of approximately 80 kilometers an hour. This added length allowed for an expansion of the passenger compartment (Stahl 66).
LZ 17 Sachsen-1913
Sachsen amidst a crowd of onlookers (Zeppelin GMBH)
This airship was built much to the same standards as the previous two but it was built to a shorter length and wider diameter. When designing previous airships, or in enlarging existing models, the common technique was simply to add a lengthening section. It was initially believed that nearly all drag was created by the frontal cross section, with very little being induced by the surface area of the rest of the vessel. The aim with Sachsen was to increase the volume of its gas cells, and thus its cargo capacity, while also keeping drag to a minimum. It was quite successful, but it entered service only a year before DELAG was dissolved at the start of the Great War, and thus had the shortest passenger service of these early airliners.
LZ 120 Bodensee-1919
Swedish soldiers help secure the landed airship. (Picryl)
Bodensee was built with a number of new design features which had become commonplace during the war. Chief of these were its teardrop shape, which cut down on drag while retaining a large hydrogen capacity; and its cruciform tail section, which improved stability and maneuverability. Despite having roughly the same hydrogen capacity as the Sachsen, built years earlier, Bodensee boasted a much higher top speed and lifting capacity, all while being considerably shorter.
The hull of the Bodensee was constructed of 17 sided rings of various dimensions, the largest being 18.6 meters in diameter. The hull was made of a more modern duralumin which made it far more resilient, and likely contributed to the long service life of the airship. Along the underside of the hull was a catwalk which gave the crew access to the engines and command gondola. Above the catwalk were the ship’s 11 hydrogen cells. The entire airship, including the gondola, was skinned in a doped cotton fabric which gave excellent weatherproofing.
The gondola itself was divided into a forward command section and a rear passenger section. The command section featured modern controls which had been commonplace for some years, most notably an electric control panel for hydrogen release. Its passenger space could be divided into five compartments seating four, with one VIP cabin in the front who paid double fare. Six more seats could be, and often were, fitted if the partitions were removed and the space was consolidated. As with the previous airliners, the cabin was well furnished with a fine wood paneling over the structural elements and specially made aluminum and leather chairs for the passengers. The decor was fairly subdued compared to the more lavish furnishings of past DELAG airships. Aft of the passenger compartment was a buffet staffed with an attendant who prepared meals with an electric hotplate. The last gondola compartment contained the restroom. (Robinson 258 Rose 196). Flights typically lasted seven or eight hours on its typical Friedrichshafen-Berlin Route. Owing to the short nature of the flights, the airship was crewed by only a dozen or so men.
The Maybach Mb IVa was the engine that powered the R-Class and all succeeding models of German military airships during the Great War. Surplus motors were used aboard the Bodensee and Nordstern. (Smithsonian)
The airship was propelled by four Maybach Mb IVa engines which were high altitude motors and were mass produced during the Great War for the R-Class, and later “height climber” Zeppelins. Owing to the lack of superchargers, they instead used incredibly high compression ratios, which meant they could not be run at high throttle below 6000ft. Some examples approached 300hp at high altitudes, but in the case of the low altitude Bodensee, they could be expected to top out at 245 hp under normal conditions. These were water cooled 23.1L inline 6’s with a bore and stroke of 165 mm and 180 mm, and a weight of 417.8 kg (Smithsonian, Robinson 258). Two motors were mounted in their own individual cars on each side of the hull, with a rear, centerline car containing two motors, side by side, and were geared to the same propeller. These were geared to a wooden 5.2 meter propeller with a reverse gear that could be used slow and maneuver the airship as it came in to land. Each engine car had a skeletal aluminum frame that was fabric skinned. The engineers worked in the cars to adjust their output, with commands being telegraphed from the control room, and to maintain them throughout long flights. In most cases this amounted to supplying them with more oil. The engines could propel Bodensee up to 132km/h, making it the fastest airship thus built. They also made it considerably overpowered and the crew had to be wary of oversteering when the engines were running near their highest output. The ship was later lengthened to extend its range and help compensate for this issue.
LZ 127 Graf Zeppelin 1928
An internal schematic of Graf Zeppelin. (Zepplinweltfahrten)
Graf Zeppelin was the largest and most advanced airship to serve with DELAG, with most of its features being tested and tried aboard the ZR 3. Graf Zeppelin’s hull was built to the restrictions of its hangar in Friedrichshafen with the 236.6m long and 30.5m airship having the familiar teardrop shape of its predecessors. Its structure was conventional, though made use of improved duraluminium and had built up sections around the gondola and the struts supporting the engine cars. The hull included two catwalks, one along the bottom, to give access to the engines, crew quarters, and gondola; and a center catwalk which gave access to the gas cells and the exterior of the airship should repairs need to be made. There were 17 hydrogen cells with a volume of about 85,000 cubic meters set above the fuel gas cells, which contained some 26,000 cubic meters of blau gas. Depending on the configuration of the airship, the combined gas capacity of hydrogen and fuel was normally 105,000 cubic meters (Robinson , Eckener 207). The use of blau gas meant a lower lifting gas capacity, but it freed up several tons of weight by eliminating the use of gasoline, and meant the airship needed less water ballast to offset the burning of a denser fuel source. The lower ballast requirements also made the airship easier to fly over long distances, as it meant the crew needed to make only minor adjustments to the airship’s trim and ballast. A small amount of liquid fuel was carried to bring the airship out of its airport, as burning it lightened the ship and aided in climbing without sacrificing any ballast water. The entire airship was skinned in treated fabric, its waterproofing treatment now containing aluminum, which gave the airship its iconic metallic sheen.
Graf Zeppelin’s Gondola (Zeppelinweltfahrten)
The lower hull contained the amenities for the crew, including the bunks, which were spaced out along the lower corridor, their restrooms, and a small lounge space where they rested and took their meals. The gondola itself was divided among the forward control rooms, and rear passenger quarters. The forwardmost was the control room, followed by a navigation room, the radio room, and kitchen. Control of the airship was managed through similar, but improved means compared to the LZ 120. The elevator controls in particular were improved by the use of a boost motor to make the difficult and physically straining job of the elevator man easier. A fully automatic gyro for rudder control was also installed, but often went unused as it was felt its impulses were too heavy and clumsy, in comparison to hand control from an experienced helmsman. Landing was done without the use of either system but was aided by the use of bubble pointers geared to both controls which accurately displayed the inclination of the airship relative to the inputs of its controllers ( ONI Lt. Cmdr. Kenworthy 3). In practice, both systems were typically only used when controllers were changing course against the wind. Navigation aboard the ship was often done through dead reckoning and star sighting, though it was also capable of radio direction-finding as well. A powerful 3 million candlepower searchlight was mounted aft of the passenger section which enabled altitude checks and drift readings in the dead of night (ONI Fulton 3,4). These systems were powered by a pair of auxiliary power units which took their fuel from the Blaugas reserves.
Heinrich Kubis, worked at some of the most fashionable hotels in Europe before becoming the world’s first flight attendant on the Schwaben. Pictured here setting a table in the Graf Zeppelin during its later years. (Wikimedia)
The kitchen was well stocked and the cook and his assistant prepared meals through the use of electrical stoves. Food was served on the airline’s own signature dishes and cutlery. There were ten two-passenger cabins, a pair of washrooms, and a lounge area that could be rearranged for dining or leisure. The original decor evoked the luxury of Pullman railcars, though the traditional, and fairly dated, wallpaper was later replaced with a coat of white paint to give the airship a more nautical feel. Passengers were less than thrilled over the fairly confined nature of their quarters and the lounge, though the annoyance of not being able to smoke was the chief complaint. After the first several voyages, the airship began to stock a larger liquor cabinet, impromptu tours of the airship were given, and a gramophone, which often played Eckener’s own extensive collection of Beethoven and Mozart, was brought aboard. Smoking however, was never allowed and the lack of insulation required passengers wear coats in cold weather.
The heavy duty, dual fuel Maybach VL-2 (Smithsonian)
Graf Zeppelin was propelled by five Maybach VL-2 motors, these being multifuel 33.3L V-12s which could run off gasoline or Blau Gas. The VL-2 was a specialized engine designed to run for long periods and to be easy to repair in flight by airship engineers. Each engine produced up to 570 hp at 1,600 RPM and weighed 1,148 kg. They had a bore and stroke of 140 mm and 180 mm. These were water cooled engines, with their radiators being at the front of the engine car where a pair of shutters controlled air flow. They were all geared to propellers via planetary 2:1 reduction gears, and like Bodensee, were reversible. They were initially all geared to two bladed wooden propellers, though all but the lower gondola would be fitted with larger four bladed 3.4 meter propellers. The lower car retained the shorter propeller as it would have otherwise run into ground clearance issues. The engines also had the benefit of a silica absorber which reduced moisture exposure and allowed them to reclaim fresh water, which proved very useful as the airship frequently crossed oceans (LT. Cmdr. TGW 3). These engines overall proved very reliable for their day, though on occasion they would encounter minor breakdowns which required a brief stoppage of all engines to fix it. They could propel the airship as fast as 128km/h, though the airship typically traveled at 112km/h which was ideal for fuel economy.
A sketch by artist Theo Matejko of one of Graf Zeppelin’s crew berths, these were spaced out along the lower catwalk. The crew lounge was above and behind the gondola. (Wikimedia)
For any considerably long voyage, a crew numbering at least thirty was required, and for regular passenger service, some 40 crewmen were aboard. On a flight from Germany to Pernambuco, Brazil on October 9, 1932, Graf Zeppelin was commanded and flown by the following: 1 commanding officer, 3 watch officers, 3 junior officers, 1 chief engineer, 1 assistant engineer officer, 1 leading engine man, 15 engine men, 2 electricians, 3 riggers, 3 radio men, 3 rudder men, 3 elevator men, and 3 stewards, these being a flight attendant and the two cooks. The longest watches belonged to the watch officers, the radiomen and riggers, and the leading engineering officers who all had a watch of four hours. Every crewman had their own bunk by the time of the regular South America flights (ONI Lt. Cmdr. T.G.W 1,2)
Graf Zeppelin’s control room, prior to the installation of instruments. (Zeppelin GMBH)
Specification:
Illustrations:
LZ-1 was the first airship built by Zeppelin and the only one that wasn’t designed by Durr. It flew quite well during its test flights but failed to attract buyers, it did however bring Eckener aboard the airship project.LZ 13 Hansa was named for the medieval Hanseatic league of Baltic merchants and entered service with DELAG in 1912. The airship would later be based in Potsdam.Bodensee was the first airliner to run on a strictly maintained schedule, as apart from the pre-war service, its aim was purely transportation and not sight seeing. Its time serving with DELAG was short, though it spent many years in Italian service under the name Esperia.
Where Bodensee set the standard for reliable service, the Graf Zeppelin set every major milestone in international air travel. Often flown under the captaincy of Dr. Eckener himself, the airship flew to many far off destinations from Tokyo to Rio De Janeiro.
Gallery
Personalities
Count Ferdinand Von Zeppelin was the foremost innovator of airship design for nearly 15 years. Stubborn, but generous, the Count remained unperturbed by setbacks that could have otherwise ended everything, and persevered to lead the world in airship piloting and development. He remained in nominal control of the company until around the start of the Great War, when his old-fashioned ways of managing the business caused friction within the new modern corporate structure of the company, with the Count subsequently entering semi-retirement. Pictured here wearing the Imperial Yacht club cap he took to wearing during flights. (Zeppelin GMBH)Dr. Ludwig Dürr was the engineering genius behind nearly every airship the company built. Involved in redesigning the LZ 1, Dürr headed nearly every design team up to the Hindenburg and the second Graf Zeppelin. While many initially found the humorless engineer odd to work alongside, Dürr was accommodating to the newcomers to the company, who brought with them new techniques and theories in aeronautics. A homebody and an eccentric, Dürr rarely left Southern Germany, but his work circled the globe. (Zeppelin GMBH)Entering the Zeppelin enterprise as a publicist, Dr. Hugo Eckener would become a pilot during DELAG’s first years, and would lead the firm following the end of the Great War. Politically savvy and ambitious, he led the firm through its darkest days and made DELAG a world renowned name once more. While Eckener never built his fleet of ocean striding airships, he would continuously break records and set nearly every major milestone when it came to modern passenger air travel. (Zeppelin GMBH)
Early Airships
Zeppelin and the Crown Prince, a patron of the Count. (Wikimedia)Schwaben comes into land, making so little noise that the sheep used to keep the grass short are undisturbed. (SFO Museum)
A DELAG advertisement. (Smithsonian)Viktoria Luise drawing a crowd. (Wikimedia)Zeppelin’s airships had cemented themselves as a cultural fixture in Germany, here Schwaben is depicted in a game where players race to visit all of Europe’s largest cities. (Stadtmuseum Berlin)
Hansa’s passenger compartment without passengers or tables. (Wikimedia)Prior to the Great War, DELAGs airships became a regular sight over many German cities.(Wikimedia)Schwaben inside its hangar. SFO museumBodensee is managed by ground teams. (Pinterest)Bodensee cruises over an airfield with a Zeppelin-Staaken bomber, built by a Zeppelin company subsidiary, and later used for advertising the Fletcher’s World magazine. (John Parker)Bodensee’s hangar. (Wikimedia)Bodensee comes in to land during its Swedish trip. (Wikimedia)
Graf Zeppelin
A ventral view of Graf Zeppelin. (Wikimedia)Graf Zeppelin landed at the airship station at Mines Field, California. (SDASM)The crew had access to much of the exterior of the airship via the ventilation shafts. On several occasions they enacted repairs on the protective fabric after harsh storms. (Life Magazine)Graf Zeppelin is joined by a Junkers F.13 as it cruises over Berlin. (Bundesarchiv)
Despite its increased size, Graf Zeppelin could easily handle ground landings, just as all previous Zeppelin airliners made. (The Atlantic)
Graf Zeppelin over Berlin’s Tempelhof field. (Bundesarchiv)While on the ground, LZ 127 was maneuvered about by ground teams. (Bundesarchiv)The Chef and his assistant at work in Graf Zeppelin’s kitchen. (Bundesarchiv)
The dining service during one of the airship’s earlier voyages, the Pullman carriage inspired decor was later replaced with a nautical theme. (Atlas obscura)The rudder control position aboard Graf Zeppelin. (Getty)LZ 127 over the Sumida river. (Old tokyo)Graf Zeppelin flies over Seville, Spain. It stopped several times at the city on its South American route. (SevillaInsolita)One of Graf Zeppelin’s engine cars. This gives a good view of the canvas frame of the unit. (Zeppelin GMbH)Graf Zeppelin cruises past Rio de Janeiro on one of its earlier South American excursions. (Wikimedia)A view of the hydrogen cell free hull of Graf Zeppelin. A ballast bag hangs at the right. (Zeppelin GMbH)
Eckener, Hugo. My Zeppelins. Putnam & Co. Ltd, 1958.
Von Zeppelin, Ferdinand. Die Luftschiffahrt Und Die Modernen Luftfahrzeuge. Berlin: Springer-Verlag, 1909.
Capt. Chollet, L. Balloon Fabrics made of Goldbeater’s Skin. NACA, 1922.
Curtis, Thomas E. The Zeppelin Airship. Smithsonian Report for 1900. 1901.
Dr. Dürr, Ludwig. The American Airship ZR-3. Zeitschrift des Vereines Deutscher Ingenieure. May 31, 1924, Vol. 68, No. 22. 1924.
Fulton, G., J. L. Kenworthy, James L. Fisher, and Edwin F. Cochrane. “LZ 127 Graf Zeppelin: Flight Reports by US Navy Officers,” October 1933, November 1934.
Mills, George H, Meister Von F.W. LZ 127 Graf Zeppelin correspondence relating to George H. Mill’s flights. 1934.
Ebner, Hans. The Present Status of Airship Construction, Especially of Airship Framing Construction. Zeitschrift fur Flugtechnik und Motorluftschifftfahrt Vol. 24, Nos. 11 and 12, June 6 and June 28, 1933 Verlag von R. Oldenbourg, Munchen und Berlin. 1933.
Romanian operated He 112s. (http://www.luftwaffephotos.com)
During the 1930’s the Aeronautica Regală Română ARR (Romanian Royal Aeronautics or Airforce) was in great need of more modern aircraft design. Their fighter force was poorly equipped with obsolete aircraft such as the PZL P.11 and P.24, being of dated Polish origin. Thus the Romanians were in desperate need of better designs. Luckily for them, the Heinkel factory was more than willing to supply them with one of their failed competitors for the new German fighter, the He 112. The Romanians were impressed and placed an order for 30 such aircraft which would remain in use up to 1946.
A brief He 112 history
Prior to the Second World War, the Luftwaffe was in need of a new and modern fighter that was to replace the older biplane fighters that were in service, such as the Arado Ar 68 and Heinkel He 51. For this reason, in May 1934 the RLM issued a competition for a new and modern fighter plane. While four companies responded to this request, only the designs from Heinkel and Messerschmitt were deemed sufficient. The Heinkel He 112 was a good design that offered generally acceptable flight characteristics and possessed a good basis for further improvements. The Bf 109 on the other hand had slightly better overall flight performance and was much simpler and cheaper to build. Given the fact that the Germans were attempting to accelerate the production of the new fighter, this was seen as a huge advantage over the He 112. Ultimately it would not be accepted for service, and only 100 or so aircraft would be built. These would be mainly sold abroad, with those remaining in Germany used for various testing and evaluation purposes.
He 112 the unsuccessful competitor of the Bf 109. Source: (luftwaffephotos.com)
While the He 112 project was canceled by the RLM, to compensate for the huge investment in resources and time to it, Heinkel was permitted to export this aircraft. A number of countries such as Austria, Japan, Romania, and Finland showed interest, but only a few actually managed to procure this aircraft, and even then, only in limited numbers.
Technical Characteristics
The He 112 was an all-metal single-engine fighter. The monocoque fuselage consisted of a metal base covered by riveted stress metal sheets. The wing was slightly gulled, with the wingtips bending upward, and had the same construction as the fuselage with a combination of metal construction covered in stressed metal sheets.
During its development life, a great number of different types of engines were tested on the He 112. For the main production version, He 112 B-2, the 700 hp Jumo 210G liquid-cooled engine was used, and some were equipped with the 680 hp Jumo 210E engine. The He 112 had a fuel capacity of 101 liters in two wing-mounted tanks, with a third 115-liter tank placed under the pilot’s seat.
The landing gear was more or less standard in design. They consisted of two larger landing wheels that retracted into the wings and one semi-retractable tail wheel. The He 112 landing gear was wide enough to provide good ground handling and stability during take-off or landing.
The cockpit received a number of modifications. Initially, it was open with a simple windshield placed in front of the pilot. Later models had a sliding canopy that was either partially or fully glazed.
While the armament was changed during the He 112’s production, the last series was equipped with two 7.92 mm MG 17 machine guns and two 2 cm Oerlikon MG FF cannons. The ammunition load for each machine gun was 500 rounds, with 60 rounds each for the cannons. If needed, two bomb racks could be placed under the wings.
In Romanian Hands
While Heinkel was desperately trying to sell more of the He 112 fighters, a potential new customer arose in the Balkans. This was Romania, which during the 1930s was severely lacking in aircraft, and the strength of its Air Force was worryingly low in comparison to most European countries. Its main fighter at this time was the obsolete P.Z.L P.11 and P.24 fighters which were acquired from Poland. A smaller number of these were purchased, with the majority being built under license. In an attempt to find the solution to this urgent problem, Romanian King Carol II himself went to visit several potential aircraft manufacturers in Europe. The Germans in particular were quite keen to have a good relationship with Romania, mostly due to its rich oil fields. The Romanians were very interested in acquiring the new Bf 109 fighter, but as it was slowly entering production in Germany, it was not yet audible in sufficient numbers for export. As a temporary solution, the He 112E, an export model based on the B version, was proposed instead. One He 112 was acquired in 1938 and was extensively tested by both the Romanian Air Force pilots and by the engineers at Industria Aeronautică Română I.A.R. (Romanian Aeronautic Industry). While some issues, such as rather poor rudder response and handling during flight, were noted, due to the urgent need for a modern fighter and a lack of alternatives, the initial order for 24 was increased to 30 aircraft. These were the He 112V-1 and B-2 versions equipped with the Jumo 210E and G engines.
The B-series was in many aspects a complete redesign of the previous series. Including the introduction of a new tail unit, and modification of the fuselage, to name a few. (luftwaffephotos.com)
Prior to shipment, a group of Romanian pilots arrived in Germany to be sufficiently trained to operate this fighter. This transition to a new, low-wing aircraft, with a fully enclosed crew cockpit and retractable landing gear, was not easy for the Romanian pilots who needed time to adapt to the new design. Once the whole training process was completed the 30 aircraft were sent to Romania. They arrived during a period of late August to early October 1939. During their flight from Germany to Romania, one He 112 was lost in an accident, while a second was damaged but later repaired at I.A.R. The Romanians tested the newly arrived He 112 against the domestically developed I.A.R.80 fighter. The Romanian aircraft proved to be a better design overall, but the He 112, thanks to its good overall handling and firepower, were also deemed satisfactory.
The newly acquired He 112 prior to the flight to Romania in 1939. (D. Bernard )
The 5th Fighter Group
The Romans used the 29 He 112 to equip the Grupul 5 Vânătoare (5th Fighter group). This unit consisted of the Escadrila 10 and 11 (10th and 11th Squadrons), later in October 1939 renamed to Scadrila 51 and 52. The main purpose of this unit was to protect the capital from any potential aerial threat. In April 1940, Germany sent one replacement aircraft for the one lost in transit the previous year, so technically Romanian operated 31 He 112’s in total. In May 1940, the He 112 was first presented to the Romanian public during a military parade.
The Romanian-Hungarian War
In Summer the rising tension between Romania and Hungary over Transylvania reached a critical point. Transylvania was part of Hungary but was lost after the First World War when it was given to Romania. In 1940, the Hungarian Army began preparing for a possible war with Romania. As neither side was willing to enter a hastily prepared war, negotiations began to find a possible solution. But despite this, there were some minor skirmishes. Hungarian aircraft made several reconnaissance flights over Romania. The Romanians responded by repositioning 12 He 112’s to the border but these failed to achieve any success against the enemy reconnaissance operation. On the 27th of August, an He 112 managed to intercept a Hungarian Ca 135 severely damaging it and forcing it to land. Ultimately, at the end of August, Romania asked Germany to arbitrate the issue regarding the disputed territory. Hungary managed to get to the northern part of Transylvania. On the 12th September 1940, one He 112 was lost when during a training flight, the aircraft caught fire from the engine compartment, and the pilot lost control and crashed ground, losing his life in this accident.
In Combat
Following the start of the Second World War with the Soviets, on the 22nd of June 1941, the 24 available (the remaining aircraft were under repairs) He 112’s were repositioned to the Focșani-North airfield in mid-June 1941. Their main task was to attack a Soviet Airfield and other ground targets. While not particularly designed for this role, thanks to its strong armament and even a small bomb load, it had enough firepower to deal serious damage. But the pilots were not trained in this manner nor the aircraft was sufficiently protected, lacking armor to protect the pilot and self-sealing fuel tanks. Occasionally they provided support cover to Romanian bombers. The Romanian main fighter in service at that time was the I.A.R. 80, so the He 112 was to fulfill secondary combat roles.
The He 112 began their first combat actions of the war against the Soviets by flying in an escort mission for the Romanian Potez 63 bombers on the 22nd of June 1941. These were heading toward the Soviet airfields at Bolgrad and Bulgarica. The attack on Bolgrad was successful despite strong Soviet anti-aircraft fire. As the Romanian air group was approaching the Bulgarica airfield they were met with resistance of some 30 Soviet I-16 fighters. One He 112 piloted by Teodor Moscu attacked two I-16 that were in the process of taking off from the airfield. Moscu managed to shoot down one I-16 on his first run. While he was pulling off from his attack another I-16 attacked his He 112. Moscu managed to shoot down this aircraft too, but his He 112 was badly damaged and losing fuel. He managed to reach a Romanian airfield and land the damaged fighter. Teodor Moscu was officially credited with achieving the first air victory for the Romanians during the War with the Soviets.
The He 112 on their first combat mission protecting the Potez 63 bombers on the 22nd of June 1941. (D. Bernard)
On the 23rd, the He 112’s mostly performed ground attack operations against Soviet targets. The same day, some 12 He 112 attacked the Bolgrad airfield. The Soviets responded by sending 7 I-153 fighters. After a brief clash, the Soviet fighters managed to shoot down one He 112. On the 24th, two He 112 were damaged in an accident. On the 28th of June, an He 112 was lost when it was shot down by Soviet anti-aircraft fire. The same day another He 112 was lost when the pilot made a mistake during landing, ultimately leading to an explosion with the aircraft and the pilot being lost. One more was badly damaged when it caught fire after battling a Soviet fighter.
On the 2nd of July, two more fighters were lost again due to Sovie ground anti-air efforts. Three days later the He 112s once again attacked the Bulgarica airfield, attacking the Soviet aircraft with bombs, cannons, and machine gun fire. One I-153 that attempted to take off, but was intercepted and shot down. One He 112 was damaged in the process. Later that day, the He 112’s provided a bomber escort mission where they engaged a group of 12 Soviet fighters. In this engagement, the Romanian pilots managed to bring down 4 enemy fighters but lost one He 112 in the process.
On the 7th of July, two He 112’s attacked a column of Soviet cars near Comrat. The He 112s managed to destroy several of these cars. An interesting event occurred on the 12th of July. On that day, a He 112 was operated by Ioan Lascu while searching for targets in the area of Valea Hârtoapelor. The pilot quickly spotted an enemy armored column and proceed to attack it with bombs. After that, he went for another run and attacked them using the He 112 two cannons. This time the Soviets returned fire and the He 112 was hit by tank gunfire. The He 112 burst into flames and hit the ground, killing the pilot in the process.
In mid-july, the Soviets launched an attack in an attempt to destroy the Romanian Țiganca-Porumbiște bridgehead. Both the Romanians and the Soviets sent substantial air forces to this battle. Thanks to some 150 aircraft, the Romanians managed to repel the Soviet attack. The He 112 saw extensive action during this battle, losing one He 112 and another aircraft being damaged.
By the end of July, only 14 He 112 were reported operational while 8 were under repairs. With the arrival of the domestically built IAR 80 fighters, the He 112 was relocated to Romania in August 1941. These were temporarily allocated for defending the Romanian skies. With the great losses suffered by the 5th Fighter group, its 52nd Squadron was disbanded and its surviving aircraft relocated to the 51st. Out of necessity, the He 112 were in October, once again brought back to the front in the Odessa region, which finally fell to the Axis by mid-October. The He 112 equipped units were placed in this area carrying out either patrolling or reconnaissance missions above the Black Sea. Enemy aircraft were rarely encountered. Only one aircraft, an I-153, was shot down in the spring of 1942 in this area. This was actually the last kill achieved by the He 112 during war. Due to its inexperienced pilot, one He 112 was lost in this area.
In Late October the Romanians issued a war report where the He 112 performance was described. While the diving speed was excellent, the low horizontal and climbing speed was deemed quite poor. The fuel tanks and the pilot seat were not armored which led to unnecessary losses in men and material. The possibility to carry six 12 kg bombs was deemed satisfactory. The quality of ammunition used was poor as too often targets that were hit, did not receive any major damage.
Many He 112s were shot down due to their unprotected fuel tanks and unarmored pilot seat. (albumwar2)
Retirement from the frontline service
Combat around Odessa would be the last major engagement of the Romanian He 112. At the start of July 1942, the 5th Fighter Group was to be equipped with the I.A.R.80 fighters. By this time the remaining He 112 were mostly stored awaiting repairs. On the 19th of July during a Soviet night bombing raid over Bucharest, one He 112 took to the sky attempting to intercept the Soviet Bombers. This was the Romanian Air Force’s first use of fighters in a night raid attack. Even in this role the He 112 would be quickly replaced with the Me 110 twin-engine fighter.
In 1943 the surviving He 112 were placed under the Corpul 3 Aerian (3rd Corps) and acted as training aircraft on several different air bases. When the Romanin switched sides in August 1944, some 9 of the 19 available He 112 were still used as trainers where they awaited the end of the war. The last two surviving Romanian He 112 aircraft were finally scrapped in 1946.
After its retirement from front-line service the surviving He 112 were used as advanced training aircraft. (worldwarphotos)
This He 112 from the 52nd Squadron survived the war, but it and all remaining aircraft would be scrapped as they were at that point obviously obsolete and beyond repair. (worldwar2.ro)
In Soviet Aircraft Role
An interesting story related to He 112 in Romanian service was that they achieved some success in cinematography. Namly for the filming of the Italian-Romanian film ‘White Squadron’, where the He 112 were reused as Soviet fighters in September 1942. These were painted in simple gray color and received a large black star. It is unusual to use a black instead of a red star, but given that this was a black-and-white movie this was not a major issue.
A set of He 112s ready for a film appearance. (T.L. Morosanu and D. A. Melinte)
Conclusion
The He 112 provided the Romanian Air Force with a capable fighter until a proper replacement could be found. With its armament, it performed generally well in ground attack operations. Due to its inadequate protection, many were brought down quite easily by enemy return fire. Due to attrition, their service life would be severely limited to only a few months of the war before being brought back to Romania to perform a secondary but vital training role. .
He 112B-2 Specifications
Wingspans
29 ft 10 in / 9.1 m
Length
30 ft 2 in / 9.22 m
Height
12 ft 7 in / 3.82 m
Wing Area
180 ft² / 17 m²
Engine
One 700 hp Jumo 210G liquid-cooled engine
Empty Weight
3,570 lbs / 1,620 kg
Maximum Take-off Weight
4,960 lbs / 2,250 kg
Climb Rate to 6 km
In 10 minutes
Maximum Speed
317 mph / 510 km/h
Cruising speed
300 mph / 484 km/h
Range
715 miles / 1,150 km
Maximum Service Ceiling
31,170 ft / 9,500 m
Crew
1 pilot
Armament
Two 20 mm (1.8 in) cannons and two machine guns 7.92 mm (0.31 in) machine guns and 60 kg bombs
Credits
Article written by Marko P.
Edited by Henry H. and Pavel. A
Ported by Henry H.
Illustration by Godzilla
Source:
Duško N. (2008) Naoružanje Drugog Svetsko Rata-Nemаčaka. Beograd
J. R. Smith and A. L. Kay (1990) German Aircraft of the Second World War, Putnam
D. Monday (2006) The Hamlyn Concise Guide To Axis Aircraft OF World War II, Bounty Books
T.L. Morosanu and D. A. Melinte Romanian (2010) Fighter Colours 1941-1945 MMP Books
D. Bernard (1996) Heinkel He 112 in Action, Signal Publication
R.S. Hirsch, U, Feist and H. J. Nowarra (1967) Heinkel 100, 112, Aero Publisher
C. Chants (2007) Aircraft of World War II, Grange Books.
190 total airframes built: 85 converted to SH-2F w/ 48 new airframes.
A SeaSprite takes on fuel aboard the Destroyer USS Briscoe. (National Archives)
Introduction
Kaman’s SH-2 proved an exceptional asset for the US Navy through the mid to late Cold War, serving a variety of roles across nearly the entirety of the surface fleet. Beginning its service as a multipurpose naval helicopter designed to ferry equipment and rescue downed fliers, the light helicopter soon played an even greater role as an anti-submarine aircraft. Replacing the outdated and clumsy DASH drone, the Seasprite incorporated cutting edge sensors to become a sub chaser that could fit on even the lightest modern frigates in the US Navy. Spanning the early sixties to the new millenium, the Seasprite served as an able light transport, search and rescue, and anti-submarine helicopter before finally being phased out by the UH-60 Seahawk.
Whirlybirds
Of all the world’s navies, that of the United States was the first to employ helicopters enmasse. While helicopters had undergone considerable development since the first usable designs had been conceived in the 1920s, they remained a clumsy novelty into the 1940s. This was until the Sikorski R-4 was developed. Igor Sikorski, born in the Kiev Governorate in the reign of Alexander II, was already an aviation legend before the Russian Civil War saw him emigrate to the United States in 1919. Having previously designed four engine biplane airliners in the Russian Empire, and several of the flying boats that saw Pan Am span half the globe, Sikorski was a name known for breaking new ground. His R-4 helicopter would build this reputation further. The greatest advantage the R-4 had over its foreign contemporaries, most notably the Focke-Anchleis 223, was its simplicity and ruggedness. The use of a main lifting rotor and anti-torque tail rotor would prove a far lighter, and more robust method of control than the transverse and intermeshing rotors that drove a number of contemporary types.
Igor Sikorskiy (right) aboard a test flight of his R-4 helicopter (wikimedia).
The R-4 reached the notice of the US armed forces through Commander William J. Kossler of the Coast Guard, after the officer had seen the XR-4 undergo a test flight in April 1942. Impressed, he invited fellow officer CDR W.A. Burton to see the helicopter. The report on the aircraft took note of its ability to conduct patrols at low speeds, and unlike US Navy airships, did not require a large hangar for storage. Initially skeptical, the Navy was later convinced of the aircraft’s anti-submarine and convoy surveillance properties. Limited production began in 1942 and testing was conducted through 1943 and ‘44, though its sub chasing capabilities were not pursued. Instead, the helicopter proved itself as an air rescue vehicle. Its first trial came on January 3, 1944, when it delivered vital blood plasma from New York City to Sandy Hook, New Jersey, through a violent storm, in order to treat sailors after a fire had sunk the destroyer USS Turner. In all, several dozen R-4s would be delivered to the Coast Guard and Navy, where they took part in a number of rescue missions across North America and the Pacific.
While the R-4 was still limited in its carrying capacity and presented pilots with challenging flight characteristics, it demonstrated the utility of helicopters to every branch of the US armed forces. Sikorski would capitalize on this over the coming decade with their heavy H-19 and H-34 helicopters. Entering service in the early fifties, these helicopters were all metal and equipped with heavy radial engines. In civilian and military service, they would prove exceptional, capable of airlifting cargo to otherwise unreachable areas. However, a new, revolutionary advancement would soon render them obsolete. In 1955, the French Allouette II became the first production helicopter to feature a geared gas turbine. The turbine provided a far better power to weight ratio than the radial engines, and it was compact, allowing it to be placed at the center of the helicopter and thus avoided the forward engine placement that made some earlier helicopters nose heavy. This engine also allowed the nimble Alloutte to possess a speed and range far beyond comparable piston engined models. From then on, it was clear that turbine power would be the future of helicopter design.
A Sikorsky ‘Choctaw’ helicopter hovers to recover astronaut Alan Shephard and a Mercury reentry capsule after the first manned US space flight. The addition of a powerful radial engine made these among the first successful heavy lift helicopters. (wikimedia)
In the US, the first experiments for this type of helicopter propulsion were pioneered by Charles Kaman’s aircraft company. The first successful experiment was achieved through combining the Boeing 502 turbine with his company’s K-225. Kaman, a former employee of Sikorsky, would develop this new helicopter along with his head designer, Anton Flettner, a German engineer who pioneered the use of intermeshing rotors. The experimental K-225 proved promising enough to warrant further development, and soon, the Kaman Aircraft company would produce a new utility helicopter along its lines. The firm’s HH-43 Huskie fire fighting and rescue helicopter fit the bill, and its later models were equipped with turboshaft engines in the late 50s.
However, the firm’s greatest success was soon to arrive, when the navy sent out a request for a new carrier-borne, lightweight helicopter.
Seasprite
The US Navy’s request for a light multipurpose and rescue helicopter was soon met with Kaman’s newest design, the Kaman Seasprite. The helicopter would settle the requirements, being capable of carrying up to 12 people, remaining compact and fuel efficient, and taking up little space aboard aircraft carriers. In the 1956 competition, Kaman’s design won handily and the next year saw a contract issued for procurement. The helicopter was the first Kaman design to feature a single main rotor, and in conjunction with the servo-flap rotor system, it was cutting edge, reliable, and possessed smooth flight characteristics.
The design, then named HU2K, first flew on July 2, 1959, and was introduced fully in December 1962. It proved to be robust with good handling, however, the single General Electric T58GE turbine left it fairly underpowered. This prevented it from taking on any new missions, but it was sufficient for the basic role it was designed for. These helicopters, later designated UH-2A and UH–2B, though largely identical, were produced until 1965, with a total of 142 airframes built.
A Kaman UH-2A/B flies alongside the USS Enterprise as a plane guard as it launches a Grumman E-2a Hawkeye. (wikimedia)
The Seasprites, supplied to utility helicopter squadrons, were distributed amongst US aircraft carriers and saw widespread use during the Vietnam War. There, they served largely as plane guards, where they took up a position alongside aircraft carriers when large scale air operations were underway. In case of an accident during take off or landing, the Seasprites would move in quickly to recover downed pilots. Search and rescue also fell under their purview, and alongside a number of other models, they pulled hundreds of airmen from the sea. As a fleet utility helicopter, they also flew ashore and between various vessels in order to transfer personnel and equipment. Medical evacuations were also among tasks these helicopters performed, moving injured personnel to ships with more substantial medical facilities. The small size and smooth controls of the Seasprite made landing on the basic helicopter facilities of most ships an easier affair compared to the bulkier Sikorsky Sea King. Its only drawback was the relatively little power offered by its small turbine engine. It could make for tricky takeoffs as the small helicopter was slow to climb.
In spite of it being underpowered, it proved to be a valuable asset to the fleet and was respected by its pilots. Naturally, the Navy wished for improved models. Kaman’s first move was to add a second turbine engine to the helicopter, the improved model being the UH-2C. As the production run had already been completed, the Navy sent Kaman the older A and B models back to the company in order to receive the upgrade. The C model was introduced in 1966, though now with its much higher speed and carrying capacity, it was soon deemed that the Seasprite was to take on a much wider scope of duties.
Sub Chaser
During the late sixties, the increased threat posed by ever more advanced models of submarines was of great concern to the US surface fleet. Even more concerning was a lack of long range anti-submarine weapons. While many ASW vessels did carry the ASROC missile, tipped with either a nuclear depth charge or a Mk 46 torpedo, there was some concern of submarines attacking from beyond the 6 to 8 mile range of this weapon. The existing long range anti-submarine weapon was the Gyrodyne DASH drone, a small drone helicopter capable of carrying depth charges and torpedoes. While it was compact, it was inflexible, and with no means of collecting additional data in the area of the suspected submarine, accuracy was very poor.
The UH-2D was an interim ASW model to test the helicopters ability to carry the equipment needed for the role. These are differentiated from the later 2F’s by their tail wheel being further out. This aircraft lacks the sonobuoy rack. (wikimedia)
This left most of the US Navy’s light surface forces, which often operated too far from the carrier to be covered by its airborne ASW umbrella, under threat from more modern submarines. The solution was found in the re-engined Seasprite. The new SH-2D represented the greatest change thus far, with the new aircraft sporting a chin mounted surface search radar, a rack to carry a Mk 46 lightweight torpedo, and a 15 chute sonobuoy rack. The small size of the helicopter would allow it to operate aboard some of the lightest frigates in the fleet, these being the Garcia-class.
The performance of the helicopter, and its ability to operate on nearly every major surface combatant, would see this mission expanded even further. Thus came the Light Airborne Multi-Purpose System, a fleet-wide program to equip most warships with helicopters in order to boost their anti-submarine and anti-surface capabilities. LAMPS I would place a now standardized SH-2F aboard nearly every frigate, destroyer, and cruiser in the fleet. In addition to the long standing utility missions, the helicopters were datalinked to their host ship to allow them to prosecute possible submarine contacts, provide long range surface surveillance, and allow for more effective over the horizon targeting of enemy surface threats.
The new SH-2F was largely the same as the proceeding UH-2D model, though it standardized the use of composite rotor blades which existed on some previous models, and its tail wheel was moved forward to enable it to better operate off of smaller ships. Some 85 Seasprites were converted to this type, and a further 48 were produced in the early 80s in order to cover a shortfall before the introduction of the SH-60B Seahawk. The new, standard LAMPS helicopter entered service in 1973.
LAMPS I
The LAMPS I program vastly increased the offensive and surveillance capabilities of participating vessels. This encompassed some half dozen ship classes ranging from the workhorse frigates of the fleet, such as the Knox and Oliver Hazard Perry, to the nuclear guided missile cruiser, Truxton. In the ASW mission, on detecting a suspected submarine, whether attacking or transiting, the ship would launch its SH-2F. Capable of using sensor data from the ship, the helicopter would move in and begin to deploy its sonobuoys, being either passive AN/SSQ-41’s or active AN/SSQ-47’s. The helicopter then relayed the sonobuoy data back to the ship for processing, and if the contact was found and classified, the helicopter would move in to attack with its Mk 46 torpedo. The onboard magnetic anomaly detector could also mark the position of a submarine if over flown by the helicopter. A ship equipped with ASROC could also join the helicopter in the attack, provided the target was in range. In the ASW role, the helicopter was a largely reactive measure, as it was unable to process its own sonobuoy data and lacked a dipping sonar, and thus required other platforms to detect the submarine first. This is not to say it lacked considerable offensive potential, as the powerful hull mounted sonar arrays aboard the Knox class frigates and Spruance class destroyers, and the OHP’s short range but highly sensitive sonar, were among the most advanced systems of their kind and could give early warning to submerged threats. The presence of the helicopter thus allowed ships to prosecute, classify, and engage submerged contacts that would otherwise be beyond the effective range of their sensors and weapons.
The Spruance class Destroyers were among the most capable anti-submarine warships used during the Cold War. With their advanced sonar systems and two helicopters, they could pose a serious threat to even the most modern nuclear submarines. (National Archives)
The Spruance class in particular could prove very dangerous to submarines at range thanks to its convergence zone sonar. The AN/SQS-53 could make use of the aforementioned phenomenon, and under ideal conditions, detect submarines at extreme ranges. These zones are where sounds are bounced off the seafloor or thermal layers into a concentrated area and are thus made dramatically louder. Convergence zones are exploited by all ASW vessels, though the specialized sonar aboard these ships allowed them to exploit sound propagated at distances far in excess of the norm. A Spruance class ship making use of a convergence zone could dispatch helicopters against submarines potentially dozens of miles away, making them among the most capable ASW vessels of the Cold War. In the absence of a convergence zone, it switched to a short to medium range mode. It shared this system with the Ticonderoga class guided missile cruiser, and the Kidd class destroyer, both of which used the same hull, however their role was air defense. These ships all transitioned to LAMPS III once it became available in the mid 1980s.
The LAMPS system featured most prominently in escort and screening vessels, namely the Knox and Oliver Hazard Perry (OHP) class frigates. The Knox class was an anti-submarine frigate with limited anti-surface capability that entered service in 1969, with 46 vessels being commissioned in all. These ships carried a single Seasprite and were armed with an ASROC launcher, which later received the capability to launch Harpoon anti-surface missiles. The OHP class carried no ASROC launcher, though they instead carried two helicopters. The last 26 of the class were LAMPS III ships and carried the heavier and more capable Sikorski Seahawk. In place of the ASROC launcher was a Mk 13 mod 4 launcher for Standard missiles and Harpoons. Both frigates carried hull sonar and towed arrays, the Knox possessing a larger hull array, and the OHP carrying a short range, high resolution hull sonar system, with a towed array being used for longer range surveillance. The difference in systems was due to the OHP being designed as a fast escort, and needed the capability to conduct passive sonar searches at speeds faster than a typical surface group. The resulting hull sonar system was thus highly sensitive, but had a decreased maximum effective range.
The Knox class was initially classified as a destroyer escort and later designated as a frigate. For mid to late Cold War vessels, they were very capable anti-submarine patrol vessels for their size with good anti-surface capabilities, featuring both a dual purpose ASROC-Harpoon launcher and a LAMPS I helicopter. (wikimedia)
In addition to the added anti-submarine mission, the Seasprite performed anti-surface support and anti-ship missile defense roles. In performing these missions, the Seasprite used its search radar to track and identify potentially hostile surface vessels. This allowed the host vessel to build a picture of enemy forces while putting itself in comparatively little direct danger. With this information, any LAMPS I vessel had early warning against potentially hostile surface vessels, and could also use the relayed information to more accurately fire Harpoon and Standard missiles over the horizon, without using its own radar and revealing itself. The extended surveillance range of a LAMPS vessel was pushed beyond 170 miles with the use of the Seasprite.
LAMPS I thoroughly improved the anti-submarine and anti-surface capabilities of much of the US fleet, with the Seasprite itself being an almost perfect off the shelf solution. While there were limitations, like the inability to perform an independent ASW search, the overall benefit of the ship not needing to prosecute sub surface contacts alone or having to reveal itself to perform a radar search in its patrol area was well worth the resources devoted to the Seasprite.
Late Career
Beyond ASW duties, Seasprites also allowed their host vessels to conduct surface surveillance over a much wider area. Here, an SH-2F identifies a natural gas carrier during Operation Desert Shield. (National archives)
By the end of the Cold War, the Seasprite had incorporated a number of improvements. These comprised a number of on board and weapon systems, perhaps most notably the introduction of the Mk 46 Mod 5, or NEARTIP, lightweight torpedo. The new model was designed to counter the latest advancements in Soviet nuclear submarine design, with the torpedo possessing an improved engine to make for a higher speed, an improved sonar transducer to increase the effective detection range of the weapon and add better countermeasure resistance, and had a new guidance and control group. The new weapon entered service in 1979, with kits being produced to convert old stocks to the new standard.
An improved model of the helicopter equipped with T700-GE-401 engines was also developed in 1985, though few were procured, as the Navy sought to increase supplies of the SH-60 Sea Hawk. Some of the improvements from the scaled back Super Seasprite did however make their way into the SH-2F. A number of LAMPS I helicopters during the mid 80s were equipped with FLIR pods for IR searches, IR jammers, chaff and flare dispensers, and an infrared sea mine detection system. Their service during the Gulf War saw them mostly perform ship to ship material and personnel transfers, mine detection, and medical evacuation roles, as Iraq possessed no submarines. Their primary mission in the theater was mine hunting duties, for which they used IR sensors in their search. They were only carried aboard lighter surface combatants during Operation Desert Storm, and weren’t present among the air wings of any of the aircraft carriers during the conflict.
After almost thirty years of service, the SH-2F was withdrawn along with most of the vessels that carried them. Its end was hastened by the withdrawal of the Knox class frigates from service and the sale of most of the short hull OHP frigates to foreign navies. The Navy would fully transition over to the Sikorsky Seahawk, a much larger and more powerful helicopter which carried two torpedoes, a dipping sonar, and incorporated sonobuoy processing capabilities.
Construction and Flight Characteristics
The Kaman SH-2F Seasprite was compact, and while conventional for a modern helicopter, was very advanced for its day. Its fuselage was watertight, possessed forward retractable landing gear, and was equipped with a variety of onboard sensors. While it could not perform waterlandings, its sealed canopy allowed it to float until the helicopter’s crew could be recovered. The pilot sat on the port side of the cockpit and the copilot/tactical coordinator, who operated the weapon systems, was seated starboard. The systems operator sat behind the pilot and operated the sonobuoy dispenser, the magnetic anomaly detector, and radar system. The systems operator lacked the equipment to process the sonobuoy data, which was instead processed aboard the LAMPS I host vessel and sent back via a data link.
An SH-2F instrument panel (wikimedia).
At the nose of the helicopter was the LN-66 surface search radar, designed for detecting both surface vessels and submarine snorkels. On the starboard pylon was the MAD streamer which worked in conjunction with an extendable antenna on the underside of the helicopter. This system worked by measuring the local strength of Earth’s magnetic field, and would spike if it encountered a large magnetic object, or in other words, a submerged submarine. Triggering a readable detection required the aircraft to over fly the contact and was thus typically used to pin the exact position of the submarine while preparing to attack after closing in during the sonobuoy search. The Seasprite carried a mix of AN/SSQ-41A passive and AN/SSQ-47B active sonar sonobuoys. The AN/SSQ-41A omni-directional passive sonobuoys operate at a depth of 60 ft for shallow searches and 300 ft for deep, and have a frequency range of 10 Hz to 20 kHz. Depending on their settings, they lasted between one to eight hours. The SSQ-47B active sonobuoy provided ranging information and operated at either 60 or 800 ft and possessed a maximum endurance of thirty minutes. Sonobuoy data was processed aboard the supporting ship and was used to localize submarine contacts that were otherwise too distant or quiet to be effectively tracked by the ship’s sensors alone. The information provided from the data link allowed the helicopter to detect, classify, and engage subsurface contacts in cooperation with the host vessel.
Re-detecting a submarine at longer ranges from the ship was difficult, as passive sonobuoys laid out in a large search pattern gave little chance of success. The best chances of re-detection on a lost contact was when it was near the surface, transiting, or maneuvering to avoid attacks from other vessels and aircraft. The standard procedure for sub chasing was to head down the azimuth of the ship’s sonar contact and to begin to lay a sonobuoy field to uncover its exact location.
The Systems operator station. To the left is the MAD readout, in the center is a scope for the surface search radar, and on the right is the (shuttered) sonobuoy display. (National archives)
The Seasprite was initially powered by a single General electric T58-GE-8F turboshaft before a second was installed on the UH-2C. These each produced up to 1,350 shp and allowed the SH-2F to travel at a top speed of 152 mph at sea level and allowed the small helicopter to carry up to 2000 lbs worth of equipment in the vertical replenishment role, with a maximum cargo hook capacity of 4000 lbs. To save fuel during emergencies, the helicopter could run on one engine on the way back to the ship. These engines were well regarded and considered very reliable.
The helicopter’s lift was provided by a 44 ft main rotor which used composite blades which were directed with servo operated flaps. These flaps are easily visible on the rotors, each having a wider chord than the rest of the blade. The flap is used to change the angle of attack of the rotor in flight and allows for smooth altitude adjustment. The anti-torque rotor at the rear of the helicopter had its blades increased from three to four going from the C to D model. The Seasprite handled well and was easy to perform a hover in, an important capability when it comes to search and rescue, and transfers to vessels without any landing areas. This was particularly important when landing on Knox class frigates, which both had significant air disturbance aft of the ship, and a very claustrophobic landing area.
In the air rescue role, the copilot would coordinate with divers and rescue crew. The cargo space of the helicopter could fit two stretchers or three seats. For water recovery of personnel, divers were carried aboard and recovered downed airmen through the use of a rescue hoist mounted on the starboard side of the helicopter. Mechanically driven, it had a capacity of 600 lbs.
Throughout the 1980’s, Seasprites were often equipped with a variety of new devices. This aircraft features two ALQ 144 IR jammers for missile defense, chaff and flare dispensers, and a FLIR imager. Crews also often removed the doors from these helicopters for faster entry and exit. (National Archives)
The Seasprite could carry a variety of unguided weapons, but rarely carried anything other than the Mk 46 torpedo, being either the Mod 0, or Mod 5 NEARTIP during the 1980s. On paper, the Seasprite could carry two torpedoes, but in practice, the second equipment position was taken up by an external fuel tank on ASW patrols. Both torpedo types measured 8.5 ft long with a diameter of 12.75 inches. The Mod 0 weighed 568 lbs, and both carried a 95 lb warhead. The Mod 0 possessed a maximum speed of 45 kts, with the NEARTIP being considerably faster. The NEARTIP provided better tracking of faster targets and better countermeasure rejection, having incorporated a new sonar transducer, control and guidance group, and a new engine which switched from solid propellant to liquid monopropellant. Prior to the introduction of the Mod 5, there was little hope for successful attacks against the fastest nuclear submarines of the 1970s. However, in confirming the location of a submarine, its position also became revealed to long range ASW aircraft which could make follow up attacks.
Other weapons included unguided 2.75 inch unguided rockets, and some rare, late examples possessed FLIR optics and could carry AGM-65 Maverick missiles. These weapons, however, were rarely ever carried. Later Seasprites carried a variety of countermeasures including an ALQ-144 tail mounted IR jammer and an ALE-39 flare and chaff dispenser. A considerable number of these helicopters were equipped with infrared jammers and flares during the 1980s.
Conclusion
An SH-2F is being used to evacuate a sailor who received severe burns, necessitating treatment off-vessel. (National Archive)
The Kaman Seasprite can be said to be among the most versatile aircraft ever operated by the US Navy. Entering service as a plane guard, the number of roles it served grew considerably over the years to encompass everything from medical evacuation, to anti-submarine duties. As the core of the LAMPS program for nearly 10 years, it gave US warships a boost in their offensive and defensive qualities against both surface and subsurface opponents.
Specification
SH-2F Seasprite
Specification
Engine
2x General Electric T58-GE-8F
Output (maximum)
2300 SHP (2700 SHP)
Maximum Weight
12800 lbs
Empty Weight
8652 lbs
Range for Utility
234 N.MI
Radius of Action for Utility
111 N.MI
Endurance for Utility (ASW) [Ferry]
2 hours (1.9 hours) [2.8 hours]
Standard Armament
1 Mk 46 Mod 0/5 Lightweight torpedo
Crew
Pilot, copilot/tactical coordinator, systems operator
Length of fuselage
40.5 ft
Width of fuselage
10 ft
Designation
Sub type
HU2K/UH-2A
Basic single engine utility helicopter
UH-2B
Minor differences in avionics, later made identical to A model
UH-2C
First two engine model
H-2
Army project, single engine
HH-2C
Combat rescue model, 7.62 side door gun emplacements, M134 rotary gun turret. Two engines.
HH-2D
Same as HH-2C but without armament. Used to test ASW equipment and loading. Two engines.
NUH-2C/D
Test helicopter, two engines.
YSH-2E
Testing helicopter for radar and ASW gear for canceled LAMPS II program
SH-2D
Early ASW model
SH-2F
Standard LAMPS I helicopter
SH-2G
SH-2F with T700 turboshaft engines, improved avionics. Small production run.
Avionics
Type
Surface Search Radar
LN-66HP
IFF
AN/APX-72
Transponder Computer
KIT-1A/TSEC
UHF Radio Set
AN/ARC-159
Secure Speech
KY-28
ICS
AN/AIC-14
TACAN
AN/ARN-52
Doppler Radar
AN/APN-182
Attitude Heading
AN/ASN-50
NAV Computer
AN/AYK-2
Plotting Board
PT-492
UHF Direction Finder
AN/ARA-25
OTPI
R1047A/A
Radar Altimeter
AN/AP-171
RAWS
AN/APQ-107
Sonobuoy receiver
AN/ARR-52
Acoustic Data Processor
AN/ASA-26B
Data Link
AN/ASK-22
Magnetic Anomaly Detector
AN/ASQ-81
Radar Warning Receiver
AN/ALR-54
Profile:
The SH-2F Seasprite was a simple, but excellent conversion of a proven airframe. Installed aboard much of the US surface fleet, it was a potent force multiplier.During the mid 80’s, the Seasprite fleet received a number of improvements. These included the ALE-39 countermeasure dispenser, the AN/ALQ-144 IR jammer for use against heat seeking missiles, and later FLIR optics.
Gallery:
The Knox class’s helicopter facilities were quite claustrophobic, and precluded the use of a larger helicopter. (National Archive)A forward view of a Seasprite aboard a Spruance class Destroyer. (National Archives)Despite its small size, the Seasprite could carry a considerable sling load between vessels. (wikimedia). A Knox class frigate during a visit to La Roche, France with its LAMPS helicopter on deck. Curiously, this ship’s Sea Sparrow launcher has been removed. (Wikimedia)The colorful MAD streamer. (Wikimedia)A Seasprite responds to a medical emergency aboard a freighter near a naval exercise. (National Archives) A Seasprite flies as a plane guard alongside the USS America. An Essex class refit carrier sails in the background. (National Archives)An SH-2F undergoes checks aboard the USS Iowa during the Northern Wedding naval exercise, 1986. (National Archives) A small number of combat rescue helicopters were converted to recover airmen from potentially dangerous coastal areas. In practice, the nose mounted gun was typically not retained. (wikimedia)With its rotors folded, the crew of the USS John Hancock prepare to stow their Seasprite. (National Archives)A snapshot taken by a Seasprite: Soviet Submarine K-324 and frigate USS McCloy (Knox class) were engaged in mutual surveillance when the submarine’s screw became entangled in the frigate’s towed sonar array. The emergency was responded to by the Soviet oceanic survey ship SSW 506 and the American destroyer USS Peterson. The K-324 was a Victor III class nuclear submarine, this type being the most numerous modern Soviet nuclear submarine of the late Cold War.
Credits:
Article written by Henry H.
Edited by Stan L. and Henry H.
Ported by Henry H.
Illustrations by Godzilla
Sources
Primary:
Standard Aircraft Characteristics Navy Model SH-2F aircraft. NAVAIR 00-110AH2-8. Commander of the Naval Air systems Command. July 1974.
Andrews, Harold. Sea Sprite. Naval Aviation New 1983 (Feb).
Naval Aviation News 1985 (May-June)
Naval Aviation News 1983 (Jan-Feb & May-Aug)
Department of Defense authorization for appropriations for fiscal year 1982 : hearings before the Committee on Armed Services, United States Senate, Ninety-seventh Congress, first session, on S. 815.
Department of Defense appropriations for 1984 hearings before a subcommittee of the Committee on Appropriations, House of Representatives, Ninety-eighth Congress, first session / Subcommittee on the Department of Defense.
Department of Defense authorization for appropriations for fiscal year 1986 : hearings before the Committee on Armed Services, United States Senate, Ninety-ninth Congress, first session, on S. 674.
Department of Defense authorization for appropriations for fiscal year 1979 : hearings before the Committee on Armed Services, United States Senate, Ninety-fifth Congress, second session, on S. 2571
Department of Defense authorization for appropriations for fiscal year 1980 : hearings before the Committee on Armed Services, United States Senate, Ninety-sixth Congress, first session, on S. 428.
Defense Department authorization and oversight hearings on H.R. 5167, Department of Defense authorization of appropriations for fiscal year 1985, and oversight of previously authorized programs before the Committee on Armed Services, House of Representatives, Ninety-eighth Congress, second session.
Secondary:
Polmar, Norman. Ships and Aircraft of the U.S. Fleet. Fifteenth Edition. US Naval Institute Press. 1993.
Sikorsky HNS-1 “Hoverfly”. United States Coast Guard.
Stuyvenberg, Luke. Helicopter Turboshafts. University of Colorado at Boulder, Department of Aerospace Engineering. 2015.
Number built: 1 prototype plus 12 production aircraft
The most modern Yugoslavian domestically developed fighter IK-3. (http://www.airwar.ru/image/idop/fww2/ik3/)
The Kingdom of Yugoslavia, despite its rather undeveloped industry and infrastructure, still possessed several aircraft manufacturing companies. During the 1930s, these produced a series of aircraft that would be adopted for military use. These were mostly training aircraft but there were also several fighter designs that would see service with the Kingdom of Yugoslavian Royal Air Force (RYAF). Among them was the IK-3 fighter, created by the well-known Yugoslavian aircraft engineers Ljubomir Ilić, Kosta Sivčev, and Slobodan Zrnić.
History
During the 1930s, the RYAF was mainly equipped with old and obsolete biplane fighters. While this would be eventually solved by the introduction of more modern, foreign designs like the Bf 109 and the Hawker Hurricane, some Yugoslavian aircraft engineers wanted to develop domestic fighter designs. This motivated two aircraft engineers from Ikarus, Ljubomir Ilić and Kosta Sivčev, to start working on such a design. They were already involved in designing a new high-wing fighter named IK-2. This aircraft proved to be superior to older biplane fighters that were in RYAF service. But after a small production series of 12 aircraft, it became obvious that this aircraft would quickly become obsolete, in contrast to other nations’ low-wing fighters.
The IK-2 fighter aircraft. (http://www.vazduhoplovnetradicijesrbije.rs/index.php/istorija/565-ikarus-ik-2)
For this reason in 1933, Ljubomir Ilić and Kosta Sivčev began working on improved fighters on their own initiative. While initially, they tested various ideas, eventually both agreed that a low-wing design was the best option. While having experience in fighter design, these two quickly realized that this project would require more work than the two engineers could achieve on their own. So they asked another engineer Slobodan Zrnić to assist in their work. All three of them worked on this project under the veil of secrecy. Finally, in 1936 they had a finalized project which was presented to the RYAF officials. After some time spent considering this new proposal, the RYAF gave the green light for it at the end of March 1937. A deal was made for the construction of a single prototype for testing and evaluation. While the IK-2 was built by Ikarus, the construction of the new aircraft was given to Rogožarski instead. Given the experience this company had working with wooden airframes, the new fighter was to have a primarily wooden construction to reduce costs and speed up development time.
Name
This project would receive the IK-3 designation. At that time it was common practice that any newly developed aircraft was to be named based on the designer’s initials. In this case, I stood for Ilić and K for Koča, which was Kosta Sivčev’s nickname. The number 3 represents the third fighter project of these two engineers.
Construction of the Prototype
After one year of work, the first prototype was completed. In appearance and design, this was quite a modern aircraft. It was built using a mixed construction and was powered by a 925 hp V-12 Hispano-Suiza 12Y29 engine. It was flight tested for the first time on the 14th of April, 1938. An initial series of test flights were carried out near the capital of Belgrade at Zemun. The test pilot at this early stage was Captain Milan Bjelanović. These flight tests lasted up to the late summer of 1938. During this time, there were no major problems reported with its design, and the aircraft was given to the RYAF for future testing.
The IK-3 first prototype was tested in 1938. (http://www.airwar.ru/image/idop/fww2/ik3/)
A commission of several RYAF officials was elected for the planned army testing and it was agreed that the whole process should last 100 flight hours. For this, the aircraft was to be fully armed which included a centerline mounted 20mm cannon which fired through the propeller hub, and two 7.92 mm machine guns placed in the upper engine cowling.
Following the conclusion of the testing by the RYAF, a report was issued in which its performance was deemed sufficient. The armament was installed and functioned without any major issues, however, it was desirable to add two more machine guns in the wings. The aircraft offered good overall flying performance though its controls were noted to be somewhat problematic and some changes were requested. To resolve this it was asked to improve the design of the flaps, by increasing their deployed angle and size. The canopy was of rather poor quality and was reflective, forcing some test pilots to fly the aircraft with open canopies. The engine had overheating problems which required extensive work before finally being solved by adding an improved cooling system. During these trials, the maximum speed achieved was slightly over 520 km/h. While not bad, the RYAF commission wanted it to be increased to at least 540 km/h, which was not achieved on this aircraft. Overall, this aircraft was deemed worth developing further by the RYAF commission, which gave a recommendation for a small series of 12 aircraft to be produced.
The production of the IK-3
Following the production orders for the IK-3, an accident happened that threatened the realization of the project. On the 19th of January 1939, an accident occurred during a test flight, and test pilot Captain Milan Pokorni was killed, and the plane was lost. A commission was formed to examine what went wrong. After analyzing the wreckage it was determined that the IK-3 prototype’s structural design was not at fault, nor did the pilot make any mistakes. Prior to this accident another pilot Dragutin Rubčić, had a harsh landing, damaging the aircraft in the process. Why this was not properly examined before another take-off by Captain Milan Pokorni is unclear. In another account, during a dive, the canopy broke free which probably made the pilot enter a climb. This seemingly caused enough force to be put on the already damaged aircraft, resulting in structural failure.
While this accident did not lead to the cancellation of the whole project, it did cause huge delays in the delivery of new aircraft. The RYAF officials wanted the aircraft to be thoroughly examined and tested before any further production order was given. Finally, in November 1939, the project received a green light again.
The second prototype, which was also the first aircraft of the first production series, was completed in December 1939. This aircraft was examined in detail over the next few months. As no major issues with the prototype were found, the production of additional 5 aircraft was completed by the 17th of April 1940. The other six aircraft could not be completed as the IK-3’s propellers had to be imported. As there were delivery problems with the last six aircraft, instead of the hydraulically controlled Hispano-type propeller, they were equipped instead with Chauviere-type propellers. It used pneumatic commands which necessitated changes to the engine and its compartment. These were finally completed in July 1940. Once all were available these were allocated to the 51st Fighter Group in July 1940. These were divided into two six-aircraft strong squadrons (the 161st and 162nd) stationed at Zemun airfield near the capital Belgrade.
Members of the 51st Fighter Group in front of their IK_3 during the summer of 1940. (https://nasaborba.com/rogozarski-ik-3-ponos-srpskog-ratnog-vazduhoplovstva/)
Second series proposal
In march 1940, the Rogožarski company proposed to the RYAF another production run of 25 to 50 new IK-3 aircraft. It was to incorporate a number of improvements like self-sealing fuel tanks, a redesigned radiator, adding radio equipment, armor for the pilot seat, an aerodynamically improved engine cowling, and a new gunsight. The company proposed that these could be completed in a period of 9 months. To speed up the developing process, one IK-3 (serial number 7) was selected to be converted as the prototype of this new series. This aircraft was completed by the end of March 1941. It was flown in early April, managing to reach a speed some 15 to 20 km faster than the standard IK-3. Its further development was stopped due to the outbreak of the war.
The second IK-3 prototype was also the first aircraft of the small production series. (http://www.airwar.ru/image/idop/fww2/ik3/)
Further IK-3 modification proposals
Some accounts claim that the aircraft was tested with a DB 601 from one of the RYAF’s imported German fighters. According to eyewitness accounts, this model was fully completed and tested. If this was true, it was not confirmed by any historical documentation or photographic evidence. At the same time a Hurricane aircraft was tested with this engine (known as LVT-1). It is possible that an eyewitness simply confused these two.
Another proposed project was the IK-3/2 two-seater trainer. It was planned to add another position to the rear of the pilot, reduce the armament to two machine guns, and move the cooling radiator some 50 cm to the rear. As a number of modern Bf 108 aircraft were acquired, this project was dropped with no prototype ever constructed.
In service, prior to the war
The newly produced IK-3 entered service at the end of 1940 and was used primarily in training flights. They were especially used to test their performance against the Bf 109, which was also in service with the RYAF. The Bf 109 offered better horizontal and climbing speed. In comparison, the IK-3 possessed better horizontal maneuverability, possessing a smaller turning radius of 260 m, the Bf 109 on the other hand had a turning radius of 320 m. The IK-3 also had a somewhat more stable armament installation, providing better accuracy during firing. As the pilots who flew on the IK-3 were not entirely accustomed to flying on modern airplanes, harsh landings were quite common. This necessitated that many IK-3 were often in workshops awaiting repairs of their landing gear units.
The IK-3’s Achilles Heel was its landing gear unit which was of poor quality. This led to a quite common breakdown of the landing gear during landings. This aircraft was damaged in this way a day before the outbreak of the war. The Germans would capture it and later, in 1942, send it to be scrapped. (http://www.airwar.ru/image/idop/fww2/ik3/)
The sixth produced IK-3 would be lost in an accident that happened on the 3rd of September 1940. During a mock dogfight with a Potez 25, pilot Anton Ercigoj lost control of the fighter and fell into the Danube river. The pilot was killed on the spot and the aircraft could not be salvaged. While it was not clear how the accident happened, it was speculated that it did occur due to the pilot being too tired from previous flights.
In War
Just prior to the outbreak of the so-called April war, from the 6th to 17th April 1941, between the Kingdom of Yugoslavia and the Axis forces, only 6 IK-3 were combat-ready. The remaining 5 aircraft were awaiting repairs. Three were located at the Rogožanski workshop in Bežanijska Kosa, and two more at the Zemun Airfield. The war began with massive Luftwaffe bombing raids on vital military, communication, infrastructure, and civilian targets. The capital, Belgrade, was a primary target of strategic bombing and was majorly hit. The whole 6th Fighter Regiment, to which the 51st Fighter Group belonged, was tasked to defend Northern Serbia and parts of Croatia and Bosnia from any potential enemy attacks. The 51st Fighter Group reinforced the 102nd Fighter Squadron equipped with Bf 109 and was tasked with defending the Northern sector. Its primary defense point was the capital Belgrade.
The 51st Fighter Group was informed of a possible enemy attack almost an hour before it occurred. At 0645, the unit was informed of two approaching enemy aircraft formations. Five minutes later, all available IK-3s took to the sky to defend the capital. One aircraft, due to engine problems, had to abort the flight and went back to the base.
During the first engagement, some 5 to 6 enemy aircraft (at least one Ju 87) were shot down. One IK-3 was shot down and three more were damaged. Two of these were badly damaged and they were not used in combat after this point. The defenders were then left with only three operational IK-3 aircraft. Late that morning, another bombing raid was launched by the enemy. While only three IK-3 were available at this point, their attack was supported by the Bf 109s from the 51st Group. While the Yugoslavian fighters reported no losses, they managed to take down one Bf 109 and damaged two Ju 87. During the first day of combat, the Germans used nearly 500 bombers which dropped some 360 tonnes of bombs on Belgrade.
The following day, enemy activity came in the form of smaller formations that attacked specific targets. The Ik-3s once again saw action, managing to shoot down more enemy aircraft. While they received no losses, many aircraft were badly damaged by enemy return fire. For example, the IK-3 fighter piloted by Milisav Semiz received 56 hits. The engine itself received some 20 direct hits. While fully covered in engine oil the pilot managed to land safely at the Zamun airfield, the aircraft had to be written off. This unit was reinforced with one IK-3 of the second series. Due to heavy enemy activity, the unit was repositioned some 50 km away from Belgrade at Ruma. For the next few days due to bad weather, the IK-3 was not used. On the 11th of April, the Yugoslavian positions were discovered by a Me 110, which proceeded to attack the airfield. It failed to do any damage, but one IK-3 began a pursuit of it. Eventually, it managed to close in on it and shoot it down. Later that day, two IK-3s took to the sky and managed to shoot down two Ju 87s.
At 1700 hours, due to an enemy ground advance, it was decided to move the available units to Bosnia. The retreat was to commence on the 12th of April, but due to sudden enemy advances and poor weather, the evacuation could not be achieved. The unit commander and pilots agreed to burn down any surviving aircraft to prevent them from falling into enemy hands. This action basically marked the end of the IK-3 service with the RYAF.
Remains of the burn-down IK-3 at Ruma airbase. (N. Miklušev Maketar Plus)
In total both the 161st and 162nd squadrons reported some 15 air victories. These included two Ju 88, one Do 17, two Ju 87, two Bf 109, three Me 110, and one He 111. The remaining claims remain a mystery.
In German hands
The victorious Germans managed to capture a number of operational and damaged IK-3s fighters. Most were captured at Rogoarski repair workshops, with a few more at the Zemun airfield, all being abandoned. This included the IK-3 with serial numbers 2151 (which was actually the second prototype) 2152, 2153, 2157, 2158, 2160, and 2161. Most of these would be left exposed to the elements, near the capital Belgrade, until 1942 when they and many other captured aircraft were scrapped. At least one IK-3 was transported back to Germany. It is unlikely that it was used for testing, and some sources suggested but instead placed in the Berlin Aviation Museum. Its fate is unknown but likely lost when the museum was bombed by the Allies in 1944.
A captured IK-3 near the Capital of Belgrade after the April war. (http://www.airwar.ru/image/idop/fww2/ik3/)Many captured Yugoslavian aircraft were gathered at the Zemun airfield. There at least three IK-3s could be seen together with some Hurricanes and Caproni aircraft. Most if not all of these would be left exposed to the elements and finally scrapped in 1942. (N. Miklušev Maketar Plus)
Technical characteristics
The IK-3 was a low-wing, mixed-construction single-seat fighter. Its fuselage consisted of welded chrome-molybdenum tubes supported with wooden stringers, and covered in duralumin skin. The rear part of the fuselage was covered in plywood and canvas. The wings were mostly made of wood with some metal links added for better structural stability. The IK-3 wings were covered with birch plywood which was in turn covered in bakelite. The ailerons were made of metal, but covered with canvas. While the trailing edge flaps were made of duralumin, assembly was made using the same materials as the wings.
The IK-3 was powered by a 925 hp, V-12 Hispano-Suiza 12Y29 liquid-cooled engine. It used a Hamilton-type constant-speed propeller. The cooling airflow was adjustable by changing the angle of the grills located on the radiator intakes.
The canopy initially was made by using concave-convex side panels. These proved to be problematic as they distorted the pilot’s vision and were replaced with simpler flat sides. The instrument controls panel and command were directly copied from French designs. The first prototype and the later first-moved aircraft of the second series were only equipped with radios.
The IK-3 was designed as a low-wing mix construction single-seat fighter. (http://www.airwar.ru/image/idop/fww2/ik3/)
The landing gear was of a conventional design consisting of two front legs which retracted outwards, with the tail wheel being fully retractable. To provide better landing, the front landing gear units had shock absorbers. The IK-3 landing gear was of rather poor quality and it often broke down during landing, and led to many aircraft being constantly under repair.
Initially, the armament consisted of one 2 cm HS 404 cannon placed behind the engine, and two 7.7 mm M.31 Darne machine guns, positioned above the engine. This was used on the prototype for firing testing. Later production models were rearmed with one 2 cm Oerlikon M.39 cannon supplied with 60 rounds of ammunition. The 7.7 mm machine guns were replaced with two 7.92 mm Browning machine guns. The ammunition load for each machine gun consisted of 500 rounds.
The IK_3 was fairly strongly armed with one 2 cm cannon and two machine guns. The cannon is actually firing through the propeller center, which is visible in this photograph. (https://nasaborba.com/rogozarski-ik-3-ponos-srpskog-ratnog-vazduhoplovstva/ )
Production
Despite its advanced design, only one prototype and 12 aircraft would be built. This took an extended period of time to be completed from December 1939 to July 1940. While proving to be one of the better domestically developed aircraft, the RYAF was reluctant to order more IK-3 fighters as it was heavily dependent on imported parts.
Production Versions
IK-3 Prototypes – Two prototypes were completed
IK-3 – Production version
IK-3 II Series – One aircraft converted to this version
IK-3 powered by a DB 601 engine – Allegedly one aircraft was modified this way, but the evidence is lacking
IK-3/2 Series – Proposal for a two-seater trainer, none ever completed
Conclusion
Despite being a very capable design, the IK-3 saw only limited production. This was mainly the case due to many of its parts having to be imported, something that could not be easily done in war-torn Europe. When used in combat, despite the limited number of operational aircraft, they performed well, with claims for 10 enemy aircraft at the loss of only one IK-3. Ultimately they could do little to turn the tide of the war, and most were either captured or destroyed by their own crews to avoid being captured.
IK-3 Specifications
Wingspans
10.3 m / 33 ft 4 in
Length
8 m / 26 ft 3 in
Height
3.5 m / 10 ft 9 in
Wing Area
16.5 m² / 178 ft²
Engine
925 hp V-12 Hispano-Suiza 12Y29 liquid-cooled engine
Empty Weight
2.070 kg / 4.560 lbs
Maximum Takeoff Weight
2.630 kg / 5.800 lbs
Maximum Speed
520 km/h / 325 mph
Cruising speed
400 km/h / 250 mph
Range
600 km / 370 miles
Maximum Service Ceiling
9,400 m
Fuel
330 Liters
Crew
1 pilot
Armament
One 2 cm cannon and two 7.92 mm machine guns
Gallery
IK-3 Prototype – 1940IK-3 51.Grupa, 6.Lovacki Puk No.2158 Br.9 April 1941IK-3 161.Eskadrilla, 51.Grupa No.218 April 1941IK-3 161.Eskadrilla, 51.Grupa No.2159 Br.10 – April 1941Possible markings for captured IK-3 being tested by a German research unit
A diagram of the improved rocket interceptor. (Nevingtonwarmuseum)
When the Me 163B entered service, it was a unique aircraft by virtue of its rocket engine. It was used as a short range interceptor for German air defense, and while it could achieve extremely high speeds, its overall design left much to be desired. These faults included a highly restrictive view from the cockpit, a lack of retractable landing gear, and limited operational endurance. In order to address some of these issues, Messerschmitt engineers developed the Me 163C.
History
While the Me 163B Komet proved to be a remarkable design, it was quite dangerous to fly and there was plenty of room for improvement. In order to make the whole aircraft as cheap as possible, some limitations had been introduced. To save weight, the aircraft had rather small dimensions which, in turn, limited the fuel load that could be stored inside. This led to a limited powered flight time of fewer than 8 minutes. In combat operations, this proved to be insufficient, but there was little that the German engineers could do to improve this. Adding internal or external auxiliary fuel tanks was not possible given the design restrictions.
Me 163B rocket interceptor, accepted into limited service. (militaryimages.net)
The position and layout of the cockpit also offered a number of issues. Most importantly, it provided the pilot with a limited field of view behind his aircraft. Another issue was the lack of retractable landing gear. The Me 163 was instead forced to use a two-wheeled detachable dolly. This was intentionally done in order to reduce weight.
Once the aircraft was in the air, the dolly was jettisoned. There were accidents regarding this system when, for example, the dolly refused to be detached from the aircraft, or even worse, when it bounced off the ground and hit the aircraft from below. On landing, the Me 163 was to use a simple retractable landing skid, placed beneath the fuselage. After landing, the aircraft was immobile and became an easy target for enemy fighters. For this reason, a normal retracting landing gear unit was desirable, but once again for the same reason as the fuel load, this could not be implemented.
To redress the previously mentioned issues, engineers at Messerschmitt began working on an improved version, the Me 163C. It incorporated a longer fuselage, an improved cockpit, and had an engine with two combustion chambers. The development of this version likely started in late 1944 or early 1945.
Production and service
The precise development history, and how many aircraft of this version were built, are the subject of considerable speculation. The fact that there are no photographs of it complicates the matter further. Most sources mentioned that only a few incomplete airframes were built by the Germans. In some sources, for example B. Rose’s Secret Projects Flying Wings and Tailless Aircraft, it is mentioned that three prototypes were completed and flight-tested in early 1945. Source E. T. Maloney and U. Feist on the other hand, mentions that only a few pre-prototype airframes were built by the time the war ended in Europe. So there are two completely different accounts in the sources.
Technical characteristics
The Me 163C, like its predecessor, was designed as a high-speed, rocket-powered, swept-wing, tailless aircraft. Given its experimental nature and its late development into the war, not much is known about its precise technical characteristics. Its overall construction would probably be similar to the previous version, with its fuselage being built of metal, and possessing wooden wings. The semi-monocoque fuselage was longer and was now 7 m compared to the original 5.84 m length.
The Me 163C was to be powered by an improved Walter 109-509C or an HWK 109-509A-2 rocket engine. In the case of the first engine, it could generate a thrust of some 1.500 kg. An auxiliary HWK 509 rocket engine would be used to provide additional endurance once the aircraft reached its cruising altitude. The maximum speed of the Me 163C was estimated at 915 km/h while the operational range was 125 km.
While the introduction of retractable landing gear was desirable, the Me 163C was not to be equipped with one, but it still received some modifications in this regard. It was to have a fully retractable tail wheel located at the bottom of the tail assembly.
The cockpit was completely redesigned. It received a fully glazed bubble-type canopy. This offered the pilot a much improved all-around view. In addition, there were provisions for pressurization equipment.
The armament used on this aircraft is not quite clear in the sources. It would have consisted of either two 2 cm MG 151 with 100 rounds of ammunition for each cannon, two 30 mm MK108 cannons with 60 rounds, or less realistically, four 30 mm MK108 cannons with 40 rounds of ammunition.
Note the redesigned canopy, auxiliary engine, and extended fuselage. (www.walterwerke.co.uk)
Cancelation of the project
While the precise development of this aircraft is unclear, most sources agree on the reasons why it was not adopted, beyond the obvious end of the war. Basically, there were two main reasons for this. First, was the lack of landing gear. The Me 163C still had to take off and land using the take-off dolly and the landing skid. This was far from perfect as the dolly, as mentioned, could potentially damage the aircraft itself after release, and the use of a sliding skid made the aircraft immobile after landing. Lastly, the auxiliary engine only extended the operational flight by an additional 1-minute, which was deemed insufficient. It was for these reasons that the Me 163C would not be adopted, and instead the development of the much improved Me 163D was prioritized.
Conclusion
Given its experimental nature, it’s late introduction, and the disagreement between sources, it is quite difficult to make the final decision on the general properties of this aircraft. Given that the project was canceled by the Germans, it is likely that besides a few experimental prototypes, no actual production aircraft were be assembled. Regardless it served as a stepping stone for the next version, the Me 163D, which was built, but it too would not be adopted for service due to the end of the war.
Me 163C Specifications
Wingspans
32 ft 2 in / 9.8 m
Length
23 ft 1 in / 7 m
Height
3 m / ft in
Wing Area
220 ft² / 20.41 m²
Engine
Walther HWL 509C-1 liquid fuel rocket engine with a max thrust of 1.500 kg
Empty Weight
4,850 lbs / 2,200 kg
Maximum Takeoff Weight
11,680 lbs / 5.300 kg
Maximum Speed
570 mph / 915 km/h
Operational range
78 mil / 125 km
Engine endurance
12 minutes
Maximum Service Ceiling
40,000 ft / 12,200 m
Crew
One pilot
Armament
Two 20 cm MG 151 (100) / Two 30 mm MK108 cannons 60
Me 163C
Credits
Article written by Marko P.
Edited by Henry H. and Medicman11
Ported by Marko P.
Illustrations by Carpaticus
Source:
D. Nešić (2008) Naoružanje Drugog Svetsko Rata-Nemcaka. Beograd.
E. T. Maloney and U. Feist (1968) Messerschmitt Me 163, Fallbrook
M. Emmerling and J. Dressel (1992) Messerschmitt Me 163 “Komet” Vol.II, Schiffer Military History
J.R. Smith and A. L. Kay (1990) German AIrcraft of the Second World War, Putnam
W. Spate and R. P. Bateson (1971) Messerschmitt Me 163 Komet, Profile Publications
M. Ziegler (1990) Messerschmitt Me 163 Komet, Schiffer Publishing
D. SHarp (2015) Luftwaffe secret jets of the Third Reich, Mortons Media Group
M. Griehl (1998) Jet Planes of the Third Reich, Monogram Aviation Publication
B. Rose (2010) Secret Projects Flying Wings and Tailless Aircraft, Midland
The enigmatic and misunderstood ‘Messerspit’ test aircraft lies at the center of a number of theories, its original purpose largely forgotten. (google.uk)
Introduction
Few aspects of the Second World War have been so misunderstood, misrepresented, and pushed into near mythology as the Luftwaffe’s test programs. Their discussion in less academic circles is dominated by rampant speculation from those who indulge in sensationalist historical stories. With respect to that, one might be surprised to find the bizarre photographs of a Spitfire Mk. VB with a Daimler Benz engine to be one of the few remaining genuine artifacts from an obscure Luftwaffe test program. With so little information publicly available, naturally, the odd plane’s origins, purpose, and performance have been drowned in a sea of speculation. However, while it is often erroneously claimed that the so-called ‘Messerspit’ was some bizarre attempt to combine the best aspects of the two planes, in reality, the aircraft was converted to settle a technical argument which had been raging in Luftwaffe research and development circles since 1942.
Engine Trouble
The history of fighter engine development is one of ceaseless improvement in power and weight which are largely achieved through improving methods of design, production, and the use of better materials. In the case of the Luftwaffe, it was not long until the chase for power was subsumed by the need to develop engines which could more reliably run on inferior materials. Following the end of the battle of Britain in the autumn of 1940, the Luftwaffe soon found itself short of several key materials necessary in building heat and corrosion resistant alloys, most notably nickel, tin, and, later, chromium and cobalt. Nearly all of these materials were available only in limited quantities across Europe, with tin, used in heavy duty piston bearings, being almost totally unavailable. This was further exacerbated by the transition to synthetic gasoline and lubricants, whose properties differed enough from their petroleum counterparts to cause trouble.
In order to cope with the restricted access to these materials, Sparrmetall economy alloys were introduced to ensure the aviation industry would have access to enough materials, albeit ones which would cause a slate of problems. The Bf 109E had nearly finished its production run before the transition to the new materials began and was soon being phased out by the new F model in late 1940, and there the trouble began. The new production DB 601N engines in these would make use of high octane C3 synthetic fuel. However, the engine was neither designed nor properly tested around this, and had instead been developed around the petroleum based C2. Beyond this, its nickel-poor, and thus corrosion prone exhaust valves, coupled with its more fragile piston and crank bearings, would soon create a web of issues that would take weeks to sort out.
A cut away of the troublesome DB 601N engine. (Flight Magazine)
The C3 fuel reacted chemically with the 109F’s rubber bag tank, and, if stored in the tank long enough, would ruin the anti-knock qualities of this fuel. When run on this degraded fuel, these engines soon suffered absolutely horrible mechanical problems, chief of which were violent vibrations which could thoroughly wreck them. The C3 fuel could also cling to the chamber walls after failing to thoroughly disperse through the fuel injectors, and then escape into the oil system. In most other aircraft, the fuel would simply boil away, but the Daimler Benz engine ran cooler than most, and thus the fuel would eventually dilute the oil until it failed to act effectively as a lubricant, resulting in increased wear or catastrophic engine failure in the worst cases.
Expecting the issue to be one of a mechanical nature, the fuel and bag were not seen as the obvious culprit. Rather, the engine mount, the air intake position, and the cooling system were suspect. This guess would be partially correct in the case of the intake. Eventually, they tracked the fuel degradation to the tank and adjusted the fuel injectors. The unreliable engine was then phased out for the DB 601E, which ran on the more common B4 fuel and was installed in the subsequent Bf 109F-3 and 4 models. Almost all Bf 109’s built after this point were run on this more common, lower performance fuel. Prior to this, the F series were restricted from running at emergency power and were at a considerable handicap in combat for much of 1941 and 42. Regardless of this impediment, many Luftwaffe fighter squadrons often found these their most successful years.
The Bf 109G initially provided no real advantage over its predecessor, and its unreliable engine would prove a particular liability in less than ideal settings, like this G-2 in Finland. (asisbiz)
Problems would resurface again when it came time to re-engine the 109 with the new DB 605A. Developed from the DB 601E, the new engine was to be a marked improvement, with its larger displacement, improved supercharger, and higher compression ratios promising a considerable increase in power. However, new material restrictions would sharply curtail the use of molybdenum, tungsten, and especially cobalt. Supplies of which practically dried up when Germany’s largest source in French North Africa had been lost after Operation Torch. Problems new and old emerged, the most egregious of which were exhaust valve failures, which were due to the low nickel content of the components, resulting in rapid corrosion and cracking. There were also lubrication failures, which were made worse after the switch was made from ball to sleeve bearings. The first Gustavs would enter service in early 1942, though they soon had their performance limited, off and on, to prevent engine failure rates from reaching unmanageable levels. As a result of these limitations, the Gustav was initially slower than the plane it was supposed to replace.
Problems were made even worse when the materials in the engines at Daimler Benz’s testing and development facilities did not match those on the production line, leading to considerable delays in destructive testing. It would eventually receive the improvements to allow it to use its emergency power setting, as exhaust valves were chrome plated and the oil scavenge system was improved, but it was clear that any major future increase in engine performance was only possible after a costly and extended development cycle. The DB 605A would finally be released from all restrictions in August of 1943, almost two years after the first Gustav left the factory.
The Blame Game
The DB 605’s flaws would be magnified in the light of a cascade of engine failures. The most publicized incident involved the loss of ace pilot Hans Marseille, who was lost in action after his engine caught fire and he died trying to escape his aircraft. (asisbiz)
Continued development of the Bf 109 was in a very precarious place, as performance improvements were expected without any major increases in engine power. These goals were largely unachievable for the time being, and thus most of those involved would try placing the fault with some other party when the unrealistic plans fell through. Willy Messerschmitt would place the blame with Daimler Benz, whose engines, he claimed, had cooling requirements that were too high, and thus required the use of larger, drag inducing radiators. In part, he was correct in that Daimler Benz’ engines ran cooler, though in doing so, he seems to have neglected issues with the plane’s radiators, which were supplied by other firms. The Bf 109 was fitted with radiators that operated under considerably lower pressures and temperatures than those used on Allied fighters, and were thus very robust, but less efficient. To his frustration, Messerschmitt was unable to increase the efficacy of the system without more efficient, high pressure radiators, which his suppliers were unable to provide.
In 1942, Messerschmitt began an increasingly adversarial correspondence with Fritz Nalinger of Daimler Benz on the state of his engines, and would request that he permit the engine to run at higher temperatures. In a letter sent in December of that year, he would draw a comparison between the ailing DB 605A and the powerful Merlin 61, then in service with the RAF. He placed particular emphasis on the higher operating temperatures and its use of radiators that were 55% smaller than those in service on the Bf 109. He would leave out that British aircraft designers were working with high pressure radiators which were far more efficient than those on his own aircraft.
At a conference with Göring at Carinhall in March of 1943, Messerschmitt would openly lay blame on Daimler Benz and Nalinger, largely reiterating the points from his correspondence. Nalinger would defend the firm by stating they had put their primary focus in designing the engine in reducing the frontal area and maintaining a high power to weight ratio, but he largely side stepped Messerschmitt’s Merlin 61 comparison by extolling the promise of the still in development DB 628. At the end of the meeting, it had become clear that both men would need to work against one another to defend their own reputations. By then, the Bf 109G had been flying for well over a year under strict engine power restrictions.
The Hybrid
To try and prove Messerschmitt wrong, Daimler Benz planned a simple and clear demonstration. They would install one of the firm’s engines in a Spitfire to show that the DB 605A did not require a large radiator to run. The Spitfire in question was EN830, a Mark Vb which had crash landed in the German occupied Jersey Islands in November of 1942. Its pilot, Lieutenant Bernard Scheidhauer, crash landed his plane after being struck by ground fire during a rhubarb raid over Northern France and a fuel leak prevented him from returning to Britain. After ditching his plane, Lieutenant Scheidhauer attempted to destroy the aircraft when it became clear that he was not on a British held channel island, however, there was insufficient fuel to burn the Spitfire. Scheidhauer was subsequently sent to Stalag Luft III, in Poland. He was among those murdered by the Gestapo after the legendary mass escape.
A standard Spitfire Mk Vb. (wikimedia)
The plane was subsequently taken in hand by the Luftwaffe, repaired, and used for trials at the Rechlin test center. It was later pulled from storage for Nallinger’s tests sometime in late 1943. The plane was re-engined with a DB 605A, though much of the rest of the aircraft was left as it was, save for the radio and armament, which were stripped out. All of the work was done at the Daimler Benz Untertürkheim factory in Stuttgart, after which it was delivered to the Luftwaffe for testing at the nearby airfield at Echterdingen. It was no simple effort to re-engine an aircraft, but it seemed to have been managed well. Testing began in the spring of 1944, with the report on the aircraft being finished May 10th.
The modified aircraft retained much of the same equipment, save for the weapons, which were removed. The avionics were likely all replaced with German alternatives. (Valengo)
The plane flew quite well and proved Nallinger right in that the DB 605A could work using a significantly smaller radiator area. It also made for an interesting comparison with the Bf 109’s radiators, as it was found that the high pressure model fitted to the Spitfire Mk V was 50% smaller but provided only 4% less cooling capacity. The tests also showed that the ‘Messerspit’ was about 25 km/h faster at lower altitudes than the original Spitfire Mk Vb thanks to its fluid coupling supercharger, which proved more efficient at low altitude. Between 4 and 6 km in altitude, the standard Mk V proved faster, before its single stage supercharger again proved less capable than the fluid coupling type on the DB 605A. The hybrid aircraft proved to be between 10 to 20 km/h slower than a Bf 109G-6 at all altitudes save for above 10.5 km, where the ‘Messerspit’ held a slightly higher speed and service ceiling. The experimental aircraft also out climbed the Bf 109 at all altitudes, however, this data is not particularly useful as the plane was unarmed and no ballast to account for its absence was installed.
Overall, the experiment produced mixed results, but proved Messerschmitt right. On one hand, the DB 605 ran effectively throughout the tests using radiators significantly smaller than were found on the Bf 109G. On the other, the type of high pressure radiator used on the Spitfire was not something that could be replicated, owing to numerous material and industrial limitations. In the end, it was Daimler Benz’s requirements that the DB 605 run cooler, and the inability of German radiator manufacturers to produce high temperature, high pressure models, that kept the Bf 109 from achieving greater performance. Following the end of the tests, the aircraft was placed in storage and was likely written off after an 8th Airforce bombing raid on the airfield at Etcherdingen on August 14, 1944.
The Ultimate Fighter?
Unfortunately, due to this unique aircraft’s strange appearance and obscurity, it has been at the center of a number of bizarre theories. Perhaps the most popular of these theories is that the Germans were trying to build a plane that blended the strengths of both the Spitfire and the Bf 109. Some go as far as to claim that the Germans had managed to build something superior to both. This first theory can immediately be written off. By early 1944, neither the Bf 109 nor the Spitfire were considered state of the art, or at the forefront of design in either country. They simply would not be considered an acceptable starting point for any new aircraft design.
However, beyond that, the ‘Messerspit’s’ performance was not particularly impressive for its day. In the official tests, it was compared to both an early Spitfire Mk Vb, which was thoroughly obsolete by the end of 1943, and a Bf 109G-6, which was mediocre by the standards of early 1944. Even then, it compared rather poorly with the G-6, possessing only a higher service ceiling while being considerably slower at almost all but the most extreme altitudes, where it held a slim advantage. To add to this, this low altitude performance gap with the Mk Vb only exists when its Merlin 45 engine is limited to +9 lbs of manifold pressure. When that engine was cleared to run at +16 lbs in November 1942, the Mk V exceeded the DB 605A powered ‘Messerspit’ at altitudes below 5.5 km in linear speed by a margin similar to the Bf 109G-6.
Spitfire Mk IX, Fw 190A-8, Bf 109G-6, P-51B (world war two photos, asisbiz, National Archives)
Aircraft (Manifold pressure)
Top Speed at Sea level (km/h)
Low blower/Speed (km/h)
high blower/Speed (km/h)
Maximum Output (hp)
Spitfire LF Mk IX Spring 1944 (18 lbs)
540
617 at 3.2km
655 at 6.7km
1720
Spitfire Mk VB Mid 1942 (9lbs)
460
N/A (single stage, single speed)
605 at 6.1km
1415
‘Messerspit’ Late Spring 1944 (1.42 ata)
488
N/A (variable speed SC)
610 at 6.5km
1454
Bf 109G-6 Mid 1943 (1.42 ata)
510
N/A (variable speed SC)
620 at 6.5km
1454
Bf 109G-6AS Early 1944 (1.42 ata)
506
N/A (variable speed SC)
653 at 8.3km
1415
Fw 190A-8 Early 1944 (1.42 ata)
558
578 at 1.5km
644 at 6.3km
1726
P-51B-15 w/ wing racks Early 1944 (67” Hg)
586
656 at 3.1km
685 at 7.2km
1720
*Values for the Spitfire Mk IX and Mustang indicate use with 100 Octane fuel and not high performance 150 octane, which became fairly common after mid-summer 1944 amongst the strategic fighter forces based in England. Likewise, Bf 109G-6 and Fw 190 performance does not reflect the use of MW50 or higher power clearances, respectively, as they were not in widespread use at the time of the tests. Unrelated, the P-51B-15 made for 627 km/h at 6.5 km with wing racks.
Compared to other contemporary frontline fighters of its day, its performance was far less impressive. The contemporary Spitfire Mk IX, with its Merlin 66 running at 18 lbs manifold pressure, outstripped the hybrid aircraft at all altitudes by a much wider margin than the Bf 109G-6. A further comparison with the Fw 190A-8 and P-51B-15 also demonstrates the continued extreme disparity in linear speed against more modern fighters. While the aircraft did demonstrate a very high climb rate, approximately 21 m/s at sea level (a Spitfire Mk IX made for 23 m/s), this can be explained by the lack of any weapons aboard. The Mk Vb was initially equipped with 2 Hispano 20 mm cannons and four .303 caliber Browning machine guns. The absence of these, and other pieces of equipment, reduced its weight by over 300 kg compared to the Mk Vb used in RAF and Luftwaffe performance trials. This resulting lightening of the aircraft, and the subsequent loss of drag with the removal of the protruding wing cannons, more than explains its high climb rate. The plane’s performance overall was very modest, and frankly did not compare well to any of its contemporaries. In the end, despite being a fusion of the Bf 109 and Spitfire, it compared rather poorly to either one.
Another theory presupposes that the plane was part of an effort to actually produce Spitfires for the Luftwaffe. The foundations for nearly all of these claims rest with an often misunderstood quote from the battle of Britain. When Reichsmarschall Herman Göring asked fighter group commander Adolf Galland if there was anything he needed, Galland responded “I should like an outfit of Spitfires for my squadron”. Galland would later clarify in his memoirs that he meant this rhetorically. In truth, he wanted a plane which could serve better as a bomber escort, something he felt the RAF’s Spitfires were better suited to, with their better visibility and low speed handling, than his own Bf 109’s, which he felt were more capable on offensive patrols. Beyond that, reverse engineering and then manufacturing an aircraft which was designed around the industrial standards and practices of another country was totally unfeasible. It also seems rather implausible that anyone would go to the trouble of building an airplane on the basis of an off hand remark made three years earlier.
Construction
A fore view of the experimental plane. (frankenplane)
The ‘Messerspit’ was built using the airframe of a later production Spitfire Mk Vb. The Mk V differed from earlier models in that it used a heavier engine mount to keep up with increases in output from new engines. It was otherwise much the same as the Mk I’s and II’s which preceded it. These planes were fairly innovative during the interwar period, being all-metal and using a semi-monocoque structure, though these features were soon made commonplace in the earliest days of the Second World War.
The fuselage contained the engine, behind which sat the fuel tank, the firewall, and then the cockpit. The tail boom was of a semi monocoque construction and contained the oxygen bottles, and radio. Aboard the ‘Messerspit’, the engine mount had to be reworked to accommodate a DB 605A, the fuel tank was likely changed to fit the new volume, and the instruments and most of the electronics were swapped for German versions. The radio appears to have been removed entirely. In all likelihood, Lt. Scheidhauer most likely smashed the instrument panel when he knew his plane was in enemy territory. Beyond that, they would have needed to convert the voltage to the German standard, and simply replacing all the equipment would have proven easier than modifying all of the existing components. There were also some instruments, like the DB 605’s RPM governor readout, that would not have had a British analogue.
The wings were elliptical with a large surface area, which granted the aircraft an excellent rate of climb and low wing loading. On the ‘Messerspit’, the inboard pair of 20 mm cannons and the outboard four .303 caliber Browning machine guns were removed and the ports were faired over. Most importantly, the radiator under the starboard wing was connected to the DB 605A engine’s oil and coolant lines. The wings were otherwise unchanged. Generally speaking, the better wheel brakes, greater visibility out the bubble canopy, and its wider wheel base would have likely made this a far more pleasant plane to fly than a Bf 109G.
A DB 605A mounted in a preserved Bf 109G-6 (wikimedia)
The engine was a Daimler Benz DB 605A, an inverted, 35.7 liter, V-12. The reason for it being inverted was to ensure the propeller shaft was as low as possible. This would enable a low mounted, centerline cannon to fire through its center without its recoil seriously jeopardizing the aircraft’s stability. They were able to achieve this using direct fuel injection, which was fairly common practice in German aviation by the start of the war, though rare elsewhere. The engine also possessed a high level of automation, which let the pilot manage the engine and most of its associated systems just through the throttle lever. These were essentially a series of linkages between components that adjusted one another as the pilot increased or decreased engine power. As such, it did not possess a true engine control unit, as was used in the BMW 801. Perhaps most impressively, the engine used a single stage, centrifugal supercharger which used a hydraulic coupling for variable transmission. The fluid coupling supercharger automatically adjusted itself barometrically, and was easily the most impressive feature of the engine, allowing it to smoothly adjust for boost as the plane climbed or descended. This allowed the aircraft to avoid the engine performance gaps between certain altitudes that were otherwise encountered with engine superchargers with multiple stages and fixed speed settings. These gaps were the result of running the supercharger at fixed, unnecessarily high speeds for a given altitude.
The engine used B4 87 octane aviation gasoline, as most of the C3 high performance stock was dedicated to squadrons flying Fw 190s. In comparison to the Merlin 45, which was originally in the Spitfire Mk.Vb, it produced 150 bhp more at sea level thanks to the fluid coupling supercharger, which saw lower pumping losses compared to the Merlin 45. The Merlin 45’s supercharger was geared to medium altitude use, and allowed the engine to outperform the DB 605A between approximately 4 and 6 km.
A DB605A mounted in a Bf 109G, cowling removed. (Norwegian air museum)
In spite of these innovative features, the engine’s output was fairly modest for its day. It produced up to 1475 PS, though this was only possible after several major modifications, such as replacing the exhaust valves for chrome plated sets and modifying the oil scavenge system by adding additional pumps and a centrifuge to improve flow and reduce foaming, respectively. Between 1942 and late 1943, the high power settings on almost all of these engines were disabled in order to keep failure rates manageable. The supercharger too would eventually lag behind its contemporaries, as despite its smoothness, its volume became a bottleneck. This was most apparent in comparison to the two-stage, intercooled models of the Rolls Royce Merlin engine. Some later models would mount an enlarged supercharger, taken from the larger DB 603, though the upgrade was not universal. Nearly all would be equipped with an anti-knock boost system in the form of MW50 in the weeks after the ‘Messerspit’s’ tests, which would boost output up to 1800 PS, though the corrosive mixture of methanol and water decreased the engine’s lifespan. Engines with the larger supercharger were designated DB 605AS, those with the boost system being DB 605M, and those with both were 605ASMs. These upgrades gave late war Bf 109’s a good degree of performance after nearly three years of mediocrity. Neither of these upgrades were present on the ‘Messerspit’.
The engine measured 101.1 × 71.9 × 174 cm, had a bore and stroke of 154 mm (6.1 in.) x 160 mm (6.3 in.), and weighed 745 kg (1,642 lb). The aircraft was equipped with the prop spinner from a Bf 109G, used the same supercharger scoop, and was likewise fitted with a two meter VDM propeller. The engine cowling of this aircraft seems to have been built for requirement.
Spitfire Mk V with DB 605A
Specification
Engine
DB 605A
Engine Output
1475PS
Gross Weight
2740kg
Maximum speed at Sea Level
488 km/h
Maximum speed at Critical Altitude
610 km/h
Max climb rate at sea level
21 m/s
Max climb rate at FTH at ~6.5km
11 m/s
Crew
Pilot
Wingspan
11.23 m
Wing Area
22.5 m^2
Conclusion
Another view of the experiment (Aviationhumor)
In the end, the ‘Messerspit’ was built to serve a single, fairly mundane purpose. It was never meant to set records, achieve any kind of technical breakthrough, or somehow be an unbeatable synthesis of two planes that had already seen their day in the sun. Above all, it was never meant to see combat nor produce a plane that would. Its only battlefield would be a corporate one.
Illustration
The Spitfire Mk V mit DB 605A, better known as the “Messerspit”.
Sources:
Primary:
Bf 109G-2 Flugzeug Handbuch (Stand Juni 1942).Der Reichsminister der Luftfahrt und Oberbefehlshaber der Luftwaffe, Berlin. November 1942.
Bf 109G-4 Flugzeug Handbuch (Stand August 1943). Der Reichsminister der Luftfahrt und Oberbefehlshaber der Luftwaffe, Berlin. September 1943.
Bf 109G-2 Flugzeug Handbuch (Stand August 1943). Der Reichsminister der Luftfahrt und Oberbefehlshaber der Luftwaffe, Berlin. October 1943.
Daimler-Benz DB 605 Inverted V-12 Engine. National Air and Space Museum Collection. Inventory number: A19670086000.
Flugzeug Flugleistungen Me 109G-Baureihen. Messerschmitt AG Augsburg. August 1943.
Horizontalgeschwindigkeit über der Flughöhe: Normaljäger Fw 190A-8. Focke-Wulf Flugzeugbau G.m.b.H. November 1943.
Leistungen Me 109G mit DB 605 AS. Messerschmitt AG. Augsburg. 22, January 1944.
P-51B-15-NA 43-24777 (Packard Merlin V-1650-7) Performance Tests on P-38J, P-47D and P-51B Airplanes Tested with 44-1 Fuel. (GRADE 104/150). 15 May, 1944.
Spitfire V Steigleitungen. Daimler Benz. Versuch Nr. 1018105428. Baumuster DB.605A. May 1944.
Spitfire Mk. VB W.3134 (Merlin 45) Brief Performance Trials. Aeroplane and Armament Experimental Establishment Boscombe Down. June 1941.
Spitfire Mk. VC AA.878 (Merlin 45) Climb, speed, and cooling tests at combat rating. Aeroplane and Armament Experimental Establishment Boscombe Down. 25 November, 1942.
Spitfire L.F. IX. RAF Aircraft Data Card, 2nd Issue. 28, October 1943. The performance of Spitfire IX aircraft fitted with high and low altitude versions of the intercooled Merlin engine. Aeroplane and Armament Experimental Establishment Boscombe Down. March 1943.
USAAF 8th Airforce Bombing Raid Records.
Secondary:
Scheidhauer, Bernard W.M. Traces of War.
Douglas, Calum E. Secret Horsepower Race: Second World War Fighter Aircraft Engine Development on the Western Front. TEMPEST, 2020.
C. Douglass, personal communication, November 25, 2022.
Price, Alfred. The Spitfire Story. Silverdale Books. 2nd Edition, 2002.
Radinger, W. & Otto W. Messerschmitt Bf 109F-K Development Testing Production. Schiffer Publishing. 1999.
Spitfire EN 830. Lostaircraft.com
Galland, Adolf. The First and the Last. Bantam. 1979.
Empire of Japan (1943) Experimental Glider Tank – One Mock-up Model
While tanks can provide excellent offensive firepower, they can’t always be easily transported to where they are needed. In the case of Japan during WW2, this was usually achieved by using ships and rail lines to transport them to where they were needed. Facing difficult terrain and disrupted shipping routes, the concept of a flying tank became a promising concept to the Japanese military hierarchy. By transporting tanks via the air, they could potentially offer benefits to the airborne troops, who were often left without proper heavy support. An exploration of this concept would lead to the creation of the Maeda Ku-6 tank glider.
The Concept of Airborne Operations
The American M22 Locust light airborne tank. (Source: Wikimedia)
The practice of dropping airborne troops behind enemy lines offers many tactical advantages, as they can attack weak points and enemy supply lines. This in turn would force the opposing side to redistribute its own forces away from the front to deal with this problem. On the other hand, airborne forces often lack proper artillery or armor support, making them vulnerable to well-equipped and directed enemies. Some nation armies responded to this by employing glider transportable light field artillery and even recoilless, high caliber guns. Transporting armored vehicles proved a more daring task to implement. Most tanks could not be easily carried inside a transport plane or even parachuted due to their weight and size. The American and British responded by developing lightly armored and armed tanks, such as the M22 Locust or the Light Tank Mk VII Tetrarch. The Soviet Union, on the other hand, designed an auxiliary glider contraption that would be used to transport a heavier tank, the Antonov A-40. This principle would also be tested by the Japanese Army during the war, which led to the creation of the Maeda Ku-6 project.
Antonov’s flying tank was unsuccessfully tested by the Soviets. (Source: Wikimedia)
Airborne Japan
The Japanese began the development of cargo glider designs for military use in 1937. Following the successful use of gliders by the Germans during their conquest of the West in May 1940, the Imperial Japanese Army began developing new gliders in June 1940. In response to this, the Imperial Japanese Navy began its own project soon after. In Japanese terminology, these were designated Kakku (English: to glide).
Both the IJA and IJN had and used parachute infantry units. It is important to note that these were relatively small units that were rarely employed in their intended role. For these reasons, their equipment was more or less the same as that of ordinary infantry formations. They saw the most active service during the fight for the Dutch East Indies in 1942. These were mainly used to capture various vital strategic points, such as airfields or weakly defended positions deep in the enemy’s rear line. Following the end of this campaign, the Japanese did not use paratrooper units in their primary role.
Japanese paratrooper IJN units had two notable deployments: in the successful Battle of Manado from 11th to the the12th January 1942, on Celebes Island, also known as Sulawesi, and in the Battle of Timor from19th February 1942-10th February 1943, where IJN paratroopers suffered heavy casualties. Their IJA counterparts were used more as a commando unit and were only ever airdropped during the invasion of Sumatra in February 1942.
Map of Japanese expansion by 1942. Some of these offensive operations also included the use of parachute units, albeit to a limited extent. (Source: https://www.pinterest.com/pin/389350330265435193/)
In 1943, attempts were made to increase their firepower, though, it is unclear how much impact the experiences from the airborne operations of February 1942 had. It was proposed to use specially designed glider tanks that could be flown to their designated target and thus provide necessary firepower to otherwise weakly armed paratrooper formations. In addition, this vehicle could be airlifted to any other theater of war without a need for them to be transported by ships, which were by this time, seriously endangered by the US Navy.
The Maeda Ku-6
The project was initiated by the Army Head Aviation Office in collaboration with the Fourth Army Research Center. The first drawings of this new design were soon ready and were allocated to the Maeda research center for the construction of a working prototype. In the early stage of development, the new tank was to be transported by a specially designed glider. But as Maeda was unable to create a glider that could transport a light tank, and so another solution was needed. Maeda engineers suggested another approach to this problem. As no glider could be developed to carry a tank, maybe the tank itself could be modified to use a glider.
While Maeda was responsible for the glider development, the design of the tank was given to Mitsubishi Heavy Industries. It is unclear if it was a completely new tank design or if Mitsubishi reused some of the existing vehicles that were in service. According to the Japanese Army and Navy Aircraft Complete Guide, the Type 98 light tank was used for the project. This tank was intended as a replacement for the Type 95 Ha-Go, but this was never achieved as it was built too late and in very small numbers.
The Type 98 light tank on which the Ku-6 was allegedly based. (Source: Wikimedia)
Name of the Project
According to E. M. Dyer, the new light tank was designated as So-Ra (Sora-Sha), which could be translated as the “sky” or “air” tank. The whole project would be designated Kuro-Sha, with the Ku and Ro, meaning the number ‘6’, taken from the Ku-6 glider designation. Lastly, the Sha stands for “tank”. An older source, J. E. Mrazek, mentions that the tank design originated in late 1939. According to Mrazek, the tank was initially designated ‘special Tank project 3’. It received the Sora-Sha designation before being changed to Kuro-Sha (English: Black Vehicle).
Technical Specification
The Ku-6 was designed as a tank transport glider. While not specified, it is likely that the Ku-6 would have been made out of wood. Due to the losses of the original documents, not much is known about its overall design. Over the years, historians based on available information devised two different designs of how this contraption may have looked.
The tank itself, due to its nature of use, had to be as light as possible. This means it would have been lightly armored and armed. The So-Ra’s total weight was slightly above 3 tonnes and would have been operated by two crew members. The driver was positioned in the front of the vehicle. He was also responsible for piloting the whole glider. Behind him, in the turret, was the commander, who was responsible for operating the main armament. This small crew would have greatly affected the tank’s overall performance. Given the limitation in size and weight, adding more crew members was not possible. In normal circumstances, the driver’s vision ports would have been small and protected. In this case, he would need to have a good and unobscured overall view of his surroundings. For this reason, he was to be provided with three large viewports. The armor was to be less than 12 mm thick. While its armament consisted of one 37 mm gun, along with a machine gun, a possible installation of a flame thrower was also considered.
The wooden mock-up of the Japanese airborne tank project. (Source: https://www.armedconflicts.com/Maeda-Ku-6-t41347)
As the tracks would cause massive drag during take-off, specially designed sleds would be attached to them to facilitate an easier take-off. According to the first proposals, the tank itself was designed to act as an improvised glider fuselage and the wings and the tail assembly would be attached to it. The tank crews would be provided with wired controls installed inside the vehicle in order to pilot it. In front of the tank, a towing cable would be added to connect it to the glider tug.
In the first version, the wings were to be attached to the So-Ra sides with the tail assembly to the rear. (Source: https://www.armedconflicts.com/Maeda-Ku-6-t41347 https://imgur.com/a/xaLcNcO)
The second version is completely different. Above the tank, a larger wing with a twin tail boom was added. These two components would be connected by struts. In both cases, once the tank hit the ground, the wing assemblies could be easily removed, which meant that the tank could immediately go into action with relative ease.
The second version was completely different in appearance. (Source: https://www.armedconflicts.com/Maeda-Ku-6-t41347)
It is unspecified which material would be used during the whole wing assembly. Given its rather late introduction and Japanese limited resources at this point, wood would likely be used. With the whole wing assembly, the Ku-6 had a length of between 12.8 to 15 m (depending on the source) with a width of 22 m and a height of 3 m. The wing area was around 60 m².
The maximum towing speed at heights of 4 km was 250 km/h. The maximum speed that could be achieved during the gliding flight itself was 174 km/h. The decent speed at 4 km altitude was 2.8 sec/m while at lower heights closer to the ground it was 2.6 sec/m. It is important to note that these are projected figures.
Testing and Project’s Fate
Due to the slow pace of work, the first operational glider prototype was completed in 1945. The tank itself was not ready by this time. As a temporary solution, a wooden mock-up of it with ballast was intended to be used instead. The prototype was taken to the sky by a Mitsubishi Ki-21 medium bomber. Almost from the start, the Ku-6 (according to E. M. Dyer the second variant was used) proved to have poor overall flight characteristics, and the pilot had a poor view. Lastly, as it was specially designed to carry the So-Ra, its transport capacity for other vehicles was very limited. The IJA officials quickly became disinterested in the Ku-6, focusing instead on the Ku-7 general purpose glider which looked more promising. Another aspect that we must take into account was the poor state of the Japanese Army in 1945. By this point, it was so battered and depleted, that undertaking an airborne operation was an impossible task. In the end, the Ku-6 would be terminated and the fate of the single prototype is unknown, but it was either scrapped or lost during Allied bombing raids.
The prototype was taken to the sky using a Mitsubishi Ki-21 aircraft. (Source: Wikimedia)The Ku-7 was a more orthodox glider design. While they were built in small numbers, they would be mainly used for testing and were not used operationally by the Japanese Army. (Source: https://listverse.com/2015/09/29/10-goofy-warplanes-of-world-war-ii/)
Conclusion
The Ku-6 seems like an interesting concept that could have offered a number of benefits to the Japanese in the early years of the Pacific theater. By 1943, when the project was initiated, the war situation for Japan had rapidly deteriorated, with the Allies pressing on all sides. In reality, the Ku-6 proved to be too flawed in design. It was difficult to control and the pilot had poor visibility. Given that it was a glider, it would make an easy target for Allied fighters which, by its construction time, had almost complete air supremacy.
Specification Maeda Ku-6
Wingspan
22 m / 72 ft 1 in
Length
15 m / 42 ft
Height
3 m / 9 ft 8 in
Wing Area
60 m² / 645 ft²
Maximum Takeoff Weight
4.200 kg / 9.260 lbs
Maximum Gliding Speed
174 km/h / 108 mph
Maximum Towing Speed
250 km/h
Crew
Two pilot/driver and the commander /gunner
Maeda Ku-6 hypothetical side wing configurationProposed version with the top wing construction.
Credits
Written by Marko P.
Edited by Henry H. & Medicman11.
Illustrated by Godzilla
Sources
D. Nešić (2008), Naoružanje Drugog Svetsko Rata-Japan, Beograd
E. M. Dyer (2009) Japanese Secret Projects Experimental Aircraft of the IJA and IJN 1939-1945, Midland
J. E. Mrazek (1977) Fighting Gliders of World War II, ST Martin Press
S. J. Zaloga (2007) Japanese tanks 1939-45, New Vanguard
Tomio Hara’s Japanese Tanks 1978
Japanese Army and Navy Aircraft Complete Guide
L. Ness (2015) Rikugun Guide To Japanese Ground Forces 1937-1945, Helion and Company
During the early 1930’s, the Royal Yugoslav Army Air Force (RYAF) was mainly equipped with old and obsolete biplane fighters. The introduction of a new fighter was desirable, but its development was hampered by the resistance of leading military officials, and pilots who still believed in the superiority of the biplane. Once Ikarus commenced production of the new high-wing IK-2, it readily demonstrated its superiority over the biplanes of the prior generation.
History of Ikarus
Ikarus was one of the first Yugoslavian domestic aircraft manufacturers. It was formed in October 1923 by a group of businessmen from the city of Novi Sad. The aircraft development department was led by Josip Mikl and Dimitrije Konjević. Josip Mikl had previously been involved in the development of hydroplanes for the Austro-Hungarian Empire during World War I, while Dimitrije Konjević was a former high-ranking officer in the Yugoslav Naval Air Force. The company saw success during the twenties and received a series of new orders for the production of aircraft, mostly for training. In 1927 thanks to increasing revenues, Ikarus opened a new production plant located in Zemun near the capital of Belgrade. It was heralded as a great success when it received a large production order for some 200 license-built Potez 25 aircraft in 1932.
Ikarus crest. Source: Wiki
The IK-2 Development
In early 1930, the main fighter of the RYAF was the aging Avia BH-33 biplane fighter. In the hopes of replacing it with a new domestically-developed fighter, two aircraft engineers from Ikarus, Ljubomir Ilić, and Kosta Sivčev began working on a new design. Interestingly this was a private venture and not ordered by the state, which was unusual.
While initially intended to be a low-wing fighter with retracting landing gear, due to fierce opposition from many Air Force officers and pilots who favored the old biplane design, this new concept had to be abandoned at an early stage of development. The two engineers then decided to proceed with a high-wing fighter design that was to be powered by a strong engine. A wooden mock-up was completed in 1933 which would be tested using a wind tunnel in Paris. After the first drawings and testing of the mock-up were completed, the result of this work was given to the RYAF officials in September 1933. After an analysis of all available data, a green light was given for the project, and Ikarus was instructed to build the first prototype.
At this early stage, the new fighter received the IK-L1 designation. As was common in Yugoslavia at the time, new aircraft designs usually received a designation based on the designer’s initials. In this case, I stand for Ilić and K stands for Koča which was Kosta Sivčev nickname. The L1 represents L for Fighter (Lovac in Yugoslavian) and the number 1 indicates the first prototype. The first fully functional prototype was completed by September 1934.
While the IK-L1 prototype was scheduled to be flight tested shortly after the first prototype was fully completed in September 1934, due to numerous delays it wasn’t conducted until April 1935. Unfortunately for the Ikarus and its design team, the first prototype had a very short and abrupt service life. As it was being prepared for the first series of test flights, an upswell of opposition, mainly from Captain Leonid Bajdak and other pilots, vehemently objected to the introduction of such a radical new design, arguing that the biplanes were superior. Regardless, Bajdak was chosen to fly test the IK-L1 prototype.
The maiden flight was made on the 22nd of April, 1935 at an airfield near Belgrade in Zemun. The first day of flying was rather successful, with the prototype exhibiting generally good performance. The test the following day produced largely similar results, but upon landing, some of the wing’s fabric skin was noted as slightly loose. Regardless, it was agreed that the testing should carry on. On the 24th of April, while flying the prototype, Captain Bajdak performed a series of unplanned aerobatics. At a height of 1,000 meters, he made a sharp dive, followed by an abrupt climb. This of course caused massive stress on the wing, which led to part of it breaking off the aircraft. Bajdak lost control and had to bail out. While he survived without injury, the IK-L1 prototype crashed and was completely destroyed.
According to Captain Bajdak in his report, he wrote that the IK-L1 had good controls and was pleasant to fly. The most obvious issues were the lack of visibility, due to the high-wing design. Another of his objections was the long take-off of some 300 meters. This was a surprisingly fair report from a pilot who professed such serious misgivings about this new design.
Work on a New Prototype
After an analysis of the IK-L1 wreckage, it was discovered that the accident was primarily due to poor build quality. As Captain Bajdak’s report was insufficient to make a final conclusion, Ikarus officials decided to produce another prototype. This time great care was taken to ensure the overall quality of its construction. Another change made was that the aircraft was built using mostly metal construction, with the exception of the aft fuselage and tail. The second prototype was designated IK-02 and took about ten months to be built, completed in June 1936. A new test pilot was chosen, Flight Lieutenant Janko Dobnikar. The series of flight tests were carried out at the newly opened test center stationed at the Zemun airfield. Early flight tests were quite satisfactory, with the IK-02 reaching a top speed of 435 km/h.
In 1937 the IK-02 prototype was tested in a mock dogfight against the Hawker Fury, the RYAF’s then-current biplane fighter. After a series of 16 such exercises, the IK-02 easily beat the Hawker Fury in almost every category of flight performance, speed, climb rate, and turning ability, among others. Frustrated by the success of the new fighter, Captain Bajdak and Lieutenant Dobnikar frequently got into fierce quarrels. It ended with Lieutenant Dobnikar challenging Captain Bajdak to a flight contest. The conditions of the contest were as follows: both pilots had to reach a height of 4 km over Zemun, after which they were to race a distance of 140 km from Belgrade to Novi Sad and back. The competition was meant to end in a mock dogfight between the two. Lieutenant Dobnikar IK-02 easily won the first two rounds of the race. The mock dogfight was fierce but Captain Bajdak’s Fury was constantly overtaken by the superior IK-02. In the end, he had to admit defeat and thus concede that the IK-02 had bested the biplane. Unfortunately, the IK-02 would be lost when it was hit by lightning during a flight. As the aircraft began to catch fire, the pilot bailed out. While he survived, the aircraft crashed and burned, completely destroying it.
Limited Production
Despite both prototypes being lost to separate accidents, their overall performance was deemed acceptable and a small production order was given. In November 1937 Ikarus was instructed to produce 12 IK-2 aircraft. The first six were delivered in December 1938, with the remaining aircraft arriving by February the following year. After a brief period of adjustment and training, the IK-2 was allocated to the 6th Fighter regiment stationed in Zemun. In October 1939, the IK-2 was redeployed to Zagreb and given to the 4th Fighter Regiment. Just prior to the Yugoslavian entry into World War II, the 4th Fighter Regiment would be repositioned to Bosanski Aleksandrovac close to Banja Luka. It was part of the 107th Squadron with the task of protecting the 8th Bomber Regiment, consisting of some 23 Bristol Blenheim bombers.
Despite being superior to other fighter designs that were in service with the RYAF, it too would be replaced by the later developed IK-3 fighter. Source: www.destinationsjourney.com
Technical Characteristics
The IK-2 was a high-wing, single-engine, almost all-metal fighter aircraft. Its fuselage was constructed of a chrome-molybdenum steel tube frame which was then covered with duralumin skin. The rear section of the fuselage close to the tail unit was covered with fabric.
The semi-cantilever wings were built using the same principle as the fuselage. The difference was that the first prototype used a fabric skin. The second prototype and the production aircraft used a duralumin skin. Two larger struts were placed beneath each wing. The tail unit was of a standard design, with one horizontal and two vertical stabilizers.
Close-up view of the IK-2 wing struts construction. Source: N. Miklušev Maketar Plus
The fixed landing gear consisted of two larger wheels and a smaller tailwheel. To help during landing the front landing gear was equipped with pneumatic shock absorbers. These were also fitted with brakes. The tailwheel was steerable. Initially, the front landing wheels were covered in a protective cover, also known as ‘spats,’ which were later removed.
The cockpit was fully enclosed. Interestingly its sliding canopy actually slid down into the fuselage sides. Quite similar to those used on ordinary cars. Due to the high wing design, the pilot’s visibility was severely limited. To somewhat remedy this issue two small glass windows were placed on the cockpit fuselage sides to help during landing.
The IK-2 cockpit was fully enclosed, but its sliding canopy slides down into the fuselage sides. Source: N. Miklušev Maketar PlusTo help the pilot cope with the cockpit’s fairly limited visibility, two smaller glass windows were placed on the cockpit fuselage sides. Source: N. Miklušev Maketar Plus
The two IK-2 prototypes were powered by an 860 hp Hispano-Suiza V-12 engine. It was equipped with an adjustable pitch three-blade propeller. The fuel tanks were located just aft of the engine in front of the cockpit. The production aircraft was powered by an 860 hp Avia HS engine. This engine was built under license in Yugoslavia. Overall performance of the aircraft did not change much, as the engine swap was mainly done to facilitate ease of maintenance.
The IK-2’s armament consisted of two 7.7 cm Darne Mle 1930 machine guns, and one 20 mm Hispano HS-9 cannon. The machine gun’s ammunition load consisted of 250 rounds each, and 60 rounds for the cannon. The cannon fired through the center of the propeller shaft, while the two machine guns were placed on each side of the front of the fuselage. Some IK-2’s had their cannon replaced with a 7.92 Browning machine gun. But by the time of the war, all available aircraft were equipped with the 20 mm cannon.
According to D. Babac, the two Darne Mle 1930 machine guns were at some point replaced with two 7.92 Browning machine guns. In addition, this author notes that the machine guns were placed above the engine compartment and not on the sides.
In War
When the war broke out on the 6th April 1941 the 4th Fighter Regiment had only 8 fully operational aircraft ready for service. Four IK-2’s suffered from mechanical breakdowns and were undergoing repairs at Zemun and Zagreb workshops. Author Z. Rendulić mentioned that only 10 IK-2 were available.
Two IK-2 (With 31 and 34 white painted markings) from the 4th Fighter Regiment were taken at Borongaj airfield in Zagreb in 1940. Note the long groove for the machine gun located above the exhaust pipes. Source: N. Miklušev Maketar Plus
In addition, the 4th Regiment had 18 to 20 Hawker Hurricanes, making this unit among the most up-to-date in the RYAF. On the first day of the war, the IK-2 was mainly used for reconnaissance. The following day, two IK-2s tried to bring down a German reconnaissance aircraft but failed to do so. One IK-2 would be lost, possibly due to mechanical breakdown. The first proper combat engagement of the IK-2 occurred on the 9th of April when during reconnaissance, a group of some 23 Bf 109 were spotted. While one IK-2 had to land to refuel, the second one provided a delayed action in hopes of giving the 4th Fighter Regiment enough time to muster its available fighters. Shortly after, some 5 or 6 IK-2 and 8 Mk.I Hurricanes joined the fight. The German fighters were attacking in well-coordinated groups, protecting each other, while the Yugoslav fighters entered the battle in a somewhat disorganized manner. After a fierce skirmish that lasted some 10 minutes, the Germans broke off and retreated back to their base of operations in Austria. The Germans lost two aircraft, while the Yugoslavians lost three, one IK-2 and two Hurricanes. In the next few days, engagements with the enemy were rare, but the IK-2 managed to shoot down one Ju 88, in addition to two other Luftwaffe aircraft.
The 4th Regiment would meet its fate on the 14th of April when the pilots decided to destroy their remaining aircraft in order to prevent them from falling into enemy hands. Despite their attempts, the Germans managed to capture one slightly damaged IK-2 belonging to the 4th Fighter Regiment. Four additional aircraft were acquired when the repair workshops in Zagreb and Belgrade were captured. Some internet sources noted that up to 9 aircraft were captured by the Germans, but this seems highly unlikely and that the number of 5 is probably correct.
While a number of IK-2 were lost due to mechanical failures, the majority would be destroyed by their own crews to prevent them from being captured by the Germans. Source: www.destinationsjourney.com
In NDH Service
Following the defeat of Yugoslavia, the Independent State of Croatia, a German puppet state was created. In June 1941 a request was made to the Germans to provide over 50 captured Yugoslavian aircraft including the IK-2, in an attempt to create a Croatian Air Force. The Germans were more than willing to give the most obsolete aircraft including four IK-2. The fate of the fifth aircraft is not clear. It may have been cannibalized for spare parts, or even sent to Germany for evaluation, but due to a lack of precise sources, we can not be sure. The Croatian Air Force regularly had problems acquiring spare parts for the Yugoslavian aircraft, as these were either destroyed, sabotaged, or commandeered by the Germans. Surprisingly the IK-2 remained in service for a few years until 1944 when they were finally withdrawn from service. They were rarely used by the Croats who often complained about its poor visibility. Sadly no IK-2 survived the war, with all likely being scrapped.
Production Versions
IK-L1 – First prototype aircraft that was lost in an accident only a few days after initial trials were conducted
IK-02 – The second more successful prototype
IK-2 – Production version
Operators
Kingdom of Yugoslavia – Eight were used during the April War.
Independent State of Croatia NDH – Used four aircraft supplied by the Germans, their service was limited.
Conclusion
The Ikarus IK-2 was one of the earliest Yugoslavian attempts to develop the first proper fighter aircraft and was intended to replace the aging biplanes then in service with the Yugoslavian Royal Air Force. While it proved to possess superior performance to biplane fighters, it too was quickly made obsolete by the introduction of new low-wing fighter aircraft. Regardless, the IK-2 was a sound design, which proved that the Yugoslav aviation industry, despite its small size, was capable of producing a viable mono-wing fighter aircraft.
The Ikarus’ powerful engine and impressive armament paved the way for Yugoslavia’s later advanced monoplane, the IK-3. Its performance in key areas gave it an advantage over the Hawker Fury. The IK-2 saw combat against Germany’s advances in the early 1940s before it was ultimately superseded by more advanced aircraft.
IK-2 Specifications
Wingspans
11.4 m / 37 ft 4 in
Length
7.88 m / 25 ft 8 in
Height
3.84 m / 12 ft 6 in
Wing Area
18 m² / 59 ft²
Engine
One 860 hp Avia HS12YCrs
Empty Weight
1.500 kg / 3.300 lbs
Maximum Takeoff Weight
1.875 kg / 4.130 lbs
Climb Rate to 5 km
In 5 minute 25 seconds
Maximum Speed
450 km/h / 280 mph
Cruising speed
250 km/h / 155 mph
Range
700 km/ miles
Maximum Service Ceiling
12,000 m / 39.370 ft
Crew
1 pilot
Armament
Two 7.7 mm machine guns and one 2 cm cannon
Yugoslav IK-2 107 Eskadrila, 34 Grupa, 4 Lovački Puk No.2104Yugoslav IK-2 107 Eskadrila, 34 Grupa, 4 Lovački Puk No.2108IK-2 in NDH service
Credits
Written by Marko P.
Edited by Henry H. & Ed J.
Illustrated by Ed J.
Sources
T. Likos and D. Čanak (1998) The Croatian Air Force In The Second World War, Nacionalna i Sveučilišna Knjižnica Zagreb
V. V. Mikić (2000) Zrakoplovstvo nezavisne države Hrvatske 1941-1945, Target Beograd
Č. Janić i O. Petrović (2011) Kratka istorija vazduhoplovstva u Srbiji, Aero Komunikacije
D.Babac Elitni vidovi Jugoslovenske vojske u Aprilskom ratu.
Z. Rendulić (2014) Lovačka Avijacija 1914-1945, Teovid
B. Dimitrijević, M. Micevski and P. Miladinović (2016) Kraljevstvo Vazduhoplovstvo 1912-1945