Tag Archives: Great Britain

Fairey Fulmar

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UK Union Jack United Kingdom (1940)
Carrier-Based Fighter Number built: 600

In the late 1930s, the British Royal Navy was in desperate need of a modern carrier-based fighter. No existing aircraft in the British inventory could effectively fulfill this role; fortunately, the aircraft manufacturer Fairey was developing a versatile light bomber. Upon closer examination, it became clear that this aircraft could be adapted for carrier operations. The result was the Fairey Fulmar, which entered service in 1940.

With little time or resources on hand as a new World War loomed, the Royal Navy’s  need for a carrier-based fighter was the found in the Fairey Fulmar. (wikimedia)

History

By the late 1930s, Japan was expanding across Asia, and there were increasing signs that a new war in Europe was on the horizon. This prompted nations such as the United Kingdom to invest in new military developments, focusing on new weapons, aircraft, and nascent technological fields which might yield decisive advantages. The Royal Air Force (RAF) saw a surge of new aircraft designs, some of which would prove to be war-winning weapons, such as the Spitfire and Hurricane fighters.

In contrast, the British Royal Navy struggled to find a suitable fighter aircraft to protect its ships. Few existing designs met the requirements, and while some older designs still had some use left in them, like the venerable Gloster Gladiator, the need for modern fighters was becoming apparent. The main airborne threats were maritime patrol aircraft that could reveal the position of the Royal Navy’s fleets, but with rapid advancements in aviation happening year over year, new dangers were soon to emerge.

Ruggedness, endurance, and advanced navigational equipment were key aspects of carrier-based fighters, but for a short-legged, landbased day fighter, these design goals were secondary at best. As a result, the Royal Navy’s requirements for a new fighter prioritized long-range radio navigation equipment and a multi-crew design. While these additions reduced the aircraft’s speed, the trade-off was considered necessary for the sake of improved coordination and operational effectiveness. In addition, the new fighter needed to carry enough fuel for a flight of at least three hours.

Developing an entirely new design was likely to take years, and given the rising tensions in Europe, the Navy wanted a solution as soon as possible. Fortunately for them, the RAF had been experimenting with a high-speed light bomber concept. In response, several companies, including Fairey Aviation and Hawker Aircraft, submitted proposals, the Fairey P.4/34 and the Hawker Henley.

However, before either of these designs reached flight testing, the RAF abandoned the fast bomber concept altogether. The Navy, on the other hand, remained highly interested in a potential fighter based on the designs. Both aircraft demonstrated impressive speed and an endurance of over four hours, making them strong candidates for the naval fighter role the navy was seeking.

To further improve their options, a third aircraft, the Phillips and Powis M.9 Kestrel, was included in the evaluation as a private venture. However, as it was initially intended as a trainer, it lacked the long-range capabilities required for naval operations and was quickly rejected.

In January 1938, after meeting with representatives from the Air Ministry, it was suggested that the Navy select the Fairey entrant as the winner. This recommendation was not based primarily on overall performance, but rather on Hawker’s already overloaded production schedule. The company was heavily engaged in manufacturing the much-needed Hurricane fighter and could not afford to divert time and resources to another project.

After analyzing its limited options, the Navy agreed to the proposal but issued a series of requirements for the new fighter. Among these were an endurance of six hours at a speed of 220 km/h (138 mph) and three hours at 427 km/h (265 mph), all at an altitude of over 3,000 meters (10,000 feet). The aircraft’s armament was to consist of at least eight 7.62 mm (0.303 in) Browning machine guns. Navy officials determined that a rear-mounted machine gun would not be necessary. While not specifically intended for attacking enemy ships, the aircraft was to be capable of carrying two 113 kg (250 lb) bombs if needed.

A more significant requirement was that the fighter should be adaptable for floatplane operations, with the ability to be equipped with floats in the field by a four-man crew in a relatively short time. Additionally, the aircraft had to be built with a sufficiently strong structure to allow for carrier landings and catapult launches.

In February, representatives from the RAF and the Navy met to discuss the proposal further and refine the specifications. During these discussions, several additional modifications were agreed upon, including raising the canopy to improve visibility during landings, and the rear observer/navigator’s compartment was to be equipped with the necessary navigational instruments. If these requirements were met, production was estimated to begin in September 1939, with a planned output of 8 aircraft per month. The new fighter was designated as Fairey Fulmar.

In March 1938, Fairey was informed of the Navy’s request for a new fighter aircraft. After examining the details, Fairey’s engineers began assessing whether the necessary modifications could be made without compromising the aircraft’s performance. By May, they informed Navy officials that their P.4/34 prototype could be adapted for the role. Following this, Fairey received a production order for 127 aircraft. Interestingly, the contract did not include the construction of an additional P.4/34 prototype for testing.

However, the project came to a halt that same month. The main issue was that Fairey was already overwhelmed with other commitments. The P.4/34’s designer, Marcel J. O. Lobelle, was instead assigned to work on the Fairey Barracuda and Albacore torpedo bombers. With his focus diverted, he was unable to dedicate time to yet another project. Despite this setback, work on the fighter continued, albeit at a slow pace.

The Munich Crisis of September 1938, in which Britain and France negotiated the fate of Czechoslovakia with Germany, further heightened tensions in Europe. With the possibility of war increasing, the order for the new fighter was expanded to 250 aircraft. However, given the existing delays, Fairey informed Navy officials that production could not commence before March 1940, seven months later than originally intended. To compensate for lost time, the monthly production was to be increased to 25 aircraft and carried out at the newly constructed Stockport factory.

First Production Aircraft

During the spring of 1939, the P.4/34 prototype was modified and tested as a potential new fighter. Following its success, two more pre-production aircraft were completed in late 1939. The first of these underwent flight testing in January 1940, while the second was not tested until May of that year. The delay occurred because the designers wanted to evaluate the installation of the Rolls-Royce RM3M engine. However, despite this test, the production aircraft that were to be gradually introduced were to be powered by the Merlin VIII engine instead.

One of the five pre-production aircraft was used as a test prototype. (D. Brown Fairey Fulmar Mks I and II Aircraft Profile 254)

Testing of the first aircraft revealed that its performance was below expectations. It achieved a maximum speed of 410 km/h (255 mph), which was lower than intended, and its climb rate was also deemed insufficient. More importantly, its operational endurance was an hour below the originally promised six hours. The primary issue was that once armament and additional equipment were installed, the aircraft’s weight increased considerably, which negatively impacted its overall performance.

On the 6th of April 1940, the first production aircraft underwent flight testing at the Aeroplane & Armament Experimental Establishment in Boscombe Down, Wiltshire. The aircraft was described as pleasant to fly and highly responsive. However, much like the prototype, its performance was subpar compared to modern land-based fighters.

Further testing was conducted by No. 770 Squadron, a trial unit stationed at Lee-on-Solent Naval Air Station. The aircraft arrived at its unit on May 10, 1940—the same day Germany launched its invasion of Western Europe. There, it was used for takeoff and landing trials, both on solid ground and on a wooden dummy flight deck designed to simulate aircraft carrier runways.

In early June 1940, the aircraft underwent flight tests aboard the newly built HMS Illustrious. The Fairey Fulmar proved easy to land, thanks to its excellent forward visibility and responsive controls. However, during takeoff, pilots noticed a tendency for the aircraft to veer to the left.

Despite its mediocre capabilities, and with no viable alternative available, the Fairey Fulmar was put into production. Manufacturing began in April 1940, and between April and December of that year, approximately 159 aircraft of this type were built.

Despite the urgent need for such fighters, production was delayed. When it finally began, it began at a slow pace, meaning the aircraft were never available in significant numbers during the war. (https://hushkit.net/2020/03/24/fairey-fulmar-how-an-absurd-lumbering-thing-became-britains-top-scoring-naval-fighter/)

Improved Mk. II Model

As Fulmar production was underway, Fairey proposed an improved variant. Essentially, it was the same aircraft but powered by a 1,260 hp Merlin 30 engine. Additionally, it was estimated that the new model could have its weight reduced by approximately 160 kg (350 lb). Once approval was granted, Fairey modified one of its already-built Fulmar aircraft to create the prototype for the new version, designated as the Fulmar II (Mk. II). The prototype modification was completed by the end of 1940, and flight testing began after nearly a month. The conversion proved successful and straightforward, requiring no major retooling of the production process. As a result, manufacturing soon transitioned to the new Fulmar II. However, despite the more powerful engine, its overall performance saw only marginal improvement. The aircraft built using older airframes, but fitted with the new engine, were designated as Fulmar I/II. By February 1943, a total of 600 aircraft of both variants had been produced.

Night Fighter Role

When the war in Europe began, Britain was among the many countries that lacked a dedicated night fighter. By 1940, the situation had not improved significantly. In particular, night raids by the Italian Air Force inflicted damage on several British ships stationed in the Mediterranean. The Royal Navy’s Fulmar fighter was ill-equipped to counter these nighttime attacks, and naval officials requested Air Interception Radar Mk. VI sets from the RAF. However, the experiment proved disappointing, as the radar performed poorly at the low altitudes where anti-ship attacks were conducted.

From 1942 onward, the older Mark IV radar system replaced the Mk. VI. This upgrade involved installing three antenna masts on the wings and in front of the aircraft. Unfortunately, this installation further reduced the Fulmar’s already slow speed by an additional 32 km/h (20 mph). Due to these challenges, none of the 100 modified aircraft were deployed to the front lines until February 1944, and it remains doubtful whether they ever saw combat.

While the Fulmar failed in its night fighter role, approximately 50 aircraft were repurposed as night-fighter trainers, making up half of the originally modified night-fighter fleet.

Long-Range Reconnaissance Role

Beginning in April 1942, some Fulmars were tested with lightweight H/F W/T radio sets. The installation proved successful, leading to further modifications for use as long-range reconnaissance aircraft equipped with improved radio equipment. These aircraft were primarily deployed for extended patrols over the Indian Ocean.

In Combat

Northern Europe

As the first Fairey Fulmars entered service in 1940, Europe was already engulfed in war. The first operational unit to receive the aircraft was No. 806 Squadron. Initially, Fulmars operated from airfields in the UK, from which they were deployed to support the defense of Norway, and later played a role in the evacuation of Allied forces from Dunkirk. Their first assigned aircraft carrier deployment was aboard the newly commissioned Illustrious, beginning in August 1940.

Later in 1941, Fulmars were used to patrol, and escort convoys bound for the Soviet Union in the North Sea. While engagements with enemy fighters were rare, one notable encounter took place in late July 1941. During this engagement, a group of Fulmars intercepted German aircraft, resulting in the destruction of two Bf 109s and one Me 110. However, the Fulmars suffered losses as well, with two aircraft being shot down in the process.

Additional units were formed as more aircraft became available. Interestingly, some Fulmars from No. 804 Squadron were assigned to operate from Fighter Catapult Ships, escorting Atlantic convoys. These were actually modified merchant ships equipped with catapult rams. Once the fighter was launched, the pilot was to fly it until he ran out of fuel. After that, the pilot would use his parachute or ditch the aircraft in the path of a ship that could recover him.

While they were intended to function as carrier-based fighters, their early operational life saw them deployed from coastal airfields in the UK. (https://www.reddit.com/r/WeirdWings/comments/c2ivcq/fairey_fulmar/)

The last recorded sortie from an aircraft carrier occurred on the 8th of February 1945. On that day, a Fulmar night fighter was dispatched to intercept an enemy aircraft approaching a convoy destined for the Soviet Union. However, en route to its target, the Fulmar’s radar equipment malfunctioned, forcing the pilot to return to the carrier. During landing, the aircraft missed the arrestor wire and instead crashed into the safety barrier.

Mediterranean Theater of War 

As production increased, additional units were formed. Such as No. 804 Squadron, which was assigned to operate Fulmars from merchant ships fitted with catapults, escorting Atlantic convoys. These vessels would launch the aircraft when an enemy target was identified. Between June and September 1940, this tactic saw limited use, with the Fulmars managing only to inflict minor damage on a German Fw 200 bomber. The Fulmars also participated in the hunt for the German Bismarck battleship but played a minor reconnaissance role.

Their combat service was primarily seen in the Mediterranean, and in September 1940, HMS Illustrious was deployed to that theater of war. At the time, the British Navy operating there lacked any form of fighter support. This role was then fulfilled by the 18 aircraft of No. 806 Squadron.

For the remainder of the year, the squadron was mainly tasked with targeting Italian reconnaissance aircraft and enemy bombers. Despite their limited numbers, they managed to shoot down 26 Italian aircraft by the end of 1940. This success was achieved by effectively coordinating their operations with Illustrious‘ radar system.

However, the situation changed drastically in 1941 when the German Luftwaffe arrived in greater numbers. Illustrious was heavily damaged, forcing No. 806 Squadron to relocate—first to Malta and then to Crete in February 1941. There, they were attached to another carrier, Formidable, and effectively merged with No. 803 Squadron.

The squadron continued operations from Formidable until May 1941, when the carrier was severely damaged by German attacks. By that time, the Fulmars had managed to shoot down at least 56 enemy aircraft, but these successes came at a cost—more than half of their already limited numbers were lost.

In April 1941, the aircraft carrier Ark Royal was tasked with protecting Gibraltar, supported by No. 807 and No. 808 Squadrons. These squadrons remained active until August 1941, when Ark Royal was sunk. Following its loss, No. 808 Squadron was disbanded, while No. 807 Squadron continued operating in the area. They were primarily assigned to patrol missions, occasionally engaging German submarines. In June, while conducting operations around Malta, they managed to shoot down five enemy aircraft but suffered the loss of three of their own. Afterward, they were redeployed to the United Kingdom.

During August 1942, No. 807 Squadron played a role in protecting a supply convoy to Malta. The British forces were supported by 18 Fulmars from No. 809 and No. 884 Squadrons. Between the 11th to 12th of August, intense battles with Axis fighters took place. The Fulmars successfully shot down at least two enemy aircraft but lost three of their own in the process.

On a few occasions, they also engaged Vichy French aircraft near Syria. In one such encounter, a group of Fulmars clashed with French D.520 fighters. Although they failed to bring down any of the French aircraft, the British lost three of their own.

The Fairey Fulmar was predominantly employed in the Mediterranean against Axis maritime patrol aircraft. (https://www.armouredcarriers.com/fairey-fulmar-models)

Deployment to China Bay

In February 1942, a small contingent of Fairey Fulmar aircraft was dispatched to China Bay to support the Royal Air Force’s General Reconnaissance No. 273 Squadron. The Fulmar equipped two squadrons, No. 803 and No. 806. No. 803 Squadron suffered heavy losses in April 1942 when four of its six aircraft were shot down during an engagement with Japanese fighters. However, the squadron managed to achieve one air victory during the battle.

On April 9, the Fulmars saw action again when they engaged Japanese bombers attacking the British aircraft carrier HMS Hermes. Despite being at a disadvantage, they successfully shot down three enemy bombers but lost two of their own aircraft in the process.

End of Service

By 1943, most Fulmar aircraft that had been deployed as day fighters were withdrawn from frontline service. The remaining aircraft were repurposed for training or used as second-line night fighters for the remainder of the war. As the war in Europe neared its end, nearly all Fulmars were replaced by the improved Fairey Firefly. In total, approximately 40 Fulmars were lost in combat by the war’s conclusion.

Technical characteristics

The Fulmar was a single-engine, all-metal carrier-based fighter. Its monocoque fuselage was constructed using metal panels placed over a tubular framework. A similar design approach was employed for the rest of the aircraft, including the wings and tail assembly.

Since the aircraft was intended to operate from smaller aircraft carriers, where space was limited, its wings needed to be foldable to maximize available room. As a result, the inner section of the wings was fixed to the fuselage, while the outer sections were designed to fold back efficiently against the sides of the aircraft. The tail assembly followed a more conventional design, featuring two horizontal stabilizers and a single vertical stabilizer.

Since it was designed to operate from an aircraft carrier, where space was limited, its wings were modified to fold. (https://www.armouredcarriers.com/fairey-fulmar-models)
Its landing gear consisted of two main wheels that retracted inward into the fuselage, along with a small fixed tail wheel. (https://en.wikipedia.org/wiki/Fairey_Fulmar)

The first prototype developed from the P.4/34 was powered by a 1,030 hp Rolls-Royce Merlin II V-12 engine. It was later replaced with a slightly more powerful Merlin VIII engine, producing 1,080 hp. With this upgrade, the aircraft achieved a maximum diving speed of 724 km/h (450 mph) and a cruising speed of 398 km/h (247 mph). The final improved variant was instead equipped with a Merlin 30 engine, delivering 1,300 hp. This modification increased the cruising speed to 417 km/h (259 mph).

Initially powered by a 1,030 hp engine, it was soon replaced with a later variant that produced 1,300 hp. While this upgrade didn’t significantly increase its maximum speed, it was certainly a welcome improvement in its rate of climb and sustained turn rate. (https://www.armouredcarriers.com/fairey-fulmar-models)

Beneath the fuselage, there were sets of catapult spools along with an arrestor hook. These components were essential for launching the aircraft from a carrier. The arrestor hook featured a V-shaped design and was secured in place by a snap lock. The pilot could release it when needed, and when not in use, only a small portion of the hook remained exposed.

The cockpit consisted of a position for the pilot and a rear, extended radio operator/observer cabin. To provide the best forward visibility, the pilot’s canopy was slightly elevated. The remaining crew compartment was fully glazed to ensure the best possible view of the surroundings. Given the distance between them, the crew communicated using a speaking tube or, when necessary, a sidetone. However, due to engine noise, the latter method was not always the most effective.

The Fulmar featured a raised pilot’s canopy, providing an excellent forward view. Additionally, its rear crew compartment was fairly long and enclosed by a glazed canopy, offering a good all-around view. (https://hushkit.net/2020/03/24/fairey-fulmar-how-an-absurd-lumbering-thing-became-britains-top-scoring-naval-fighter/)

The armament of this aircraft consisted of eight 7.62 mm machine guns mounted in the wings. Each gun was initially supplied with 750 rounds of ammunition, which was later increased to 1,000. While eight machine guns may sound formidable, in practice, they lacked the firepower needed to inflict serious damage on larger targets, given their relatively small caliber.

The ground crew in the process of loading each gun with 750-round belts. Later, this was increased to 1,000 rounds per machine gun. (https://www.destinationsjourney.com/historical-military-photographs/fairey-fulmar/)

For example, the British recorded an incident in which three Fulmar fighters engaged a single Blohm & Voss BV 138, a long-range maritime reconnaissance aircraft. Despite firing nearly 18,000 rounds at it, the German aircraft suffered no significant damage and managed to escape.

To address this issue, the British considered equipping the Fulmar with heavier 12.7 mm (0.5 in) machine guns. While the installation proved feasible, a shortage of these weapons meant that very few aircraft were ever fitted with them. Around 100 units were slated for modification to carry four of these heavy machine guns, but only a small number actually received the upgrade.

Despite having enough space, no attempt was made to mount a rear-positioned machine gun, despite the crew’s insistence on doing so. Instead, the crew improvised with whatever defensive weapons they could find. Some used Thompson submachine guns, while others relied on signal pistols. The most unusual weapon employed for self-defense was a bundle of standard-issue toilet paper, secured with an elastic band. When thrown out of the aircraft, the band would snap, creating an explosion of paper that, on rare occasions, helped distract or deter enemy pursuers.

The Fulmar was originally designed to carry a bomb load consisting of either two 45 kg or 113 kg (100-250 lbs) bombs. However, this was never actually implemented, as no bomb racks were installed to accommodate such a load. On rare occasions, small 9 to 18 kg (20-40 lbs) bombs were carried to engage enemy anti-aircraft batteries during support missions.

Production 

Production of this aircraft began in May 1940 and ended in February 1943. During that time, 250 units of the Mk. I variant was built, followed by 350 of the later Mk. II variant. In total, approximately 600 aircraft of this type were produced during the war.

Production Versions

  • Fairey Fulmar Mk.I– First production variant
  • Fairey Fulmar Mk.II– Second production variant equipped with a Merlin 30 engine
  • Night Fighter/trainer– Modified to act as a night fighter, supplied with radio equipment. In total 100 were converted to this role of which half were reused as night fighter trainers
  • Long-Range Reconnaissance – Equipped with long-range radio equipment

Surviving Aircraft

Only one of the approximately 600 aircraft of this type has survived to this day. This surviving example is actually the first prototype, which was later used for civilian purposes after the war. Today, it is on display at the Fleet Air Arm Museum in Yeovilton.

The only surviving Fairey Fulmar  can be seen at the Fleet Air Arm Museum in Yeovilton. (https://en.wikipedia.org/wiki/Fairey_Fulmar)

Conclusion 

The Fairey Fulmar was an attempt to adapt an existing aircraft design into a fighter type that was in high demand by the British Royal Navy. While it met most of the required specifications, it was too slow and heavy to compete effectively against faster, purpose-built fighters. Its

armament, despite featuring multiple machine guns, was also still somewhat underpowered. However, this did not prevent the Fulmar from achieving remarkable success for a relatively large fighter. Despite its small production numbers, it proved effective against Italian aircraft and, on occasion, even German fighters. By 1943, however, it was becoming obsolete, and by the end of the war, all remaining Fulmars had been retired from service. Nonetheless, it paved the way for later, more advanced naval aircraft.

Fairey Fulmar MK.I  Specifications
Wingspans 14.14 m /  46  ft 4 in
Length 13.42 m /  40 ft 2 in
Height 4.27 m / 14 ft
Wing Area 31.8 m² / 342 ft²
Engine 1.080 hp Merilin VIII V-12 piston engine
Empty Weight 3,955 kg / 8,720 lbs
Maximum Takeoff Weight 4,853 kg / 10,700  lbs
Maximum Speed km/h /450  mph
Cruising speed 398 km/h / 247 mph
Maximum Service Ceiling m / 16,000 ft
Crew One pilot, one observer/navigator
Armament
  • Eight 7.62 mm Browning machine guns

Illustration

Credits

  • Article written by Marko P.
  • Edited by  Henry H.
  • Illustration by Oussama Mohamed “Godzilla”

Source:

  • D. Brown (1973) Fairey Fulmar Mks I and II Aircraft Profile 254, Profile Publication
  • D. Nešić (2008) Naoružanje Drugog Svetskog Rata Velika Britanija, Vojnoizdavački zavod
  • D. Monday (2007) British Aircraft of World War Two, Chancellor Press
  • F. Crosby (2006) The Complete Guide to Fighters and Bombers Of The World, Hermes Hause
  • https://www.armouredcarriers.com/fairey-fulmar-models

 

 

Hafner Rotabuggy

UK, , , , , , , ,

UK Union Jack United Kingdom (1943-1944)
Rotor Kite Transport – One prototype

During the Second World War, airborne troops became an essential component of modern military strategy. They allowed armies to wreak havoc on unprotected rear areas by destroying critical targets, such as the enemy’s vital command structures, and the infrastructure supporting their army. However, one major drawback was that once on the ground, these troops were lightly equipped and moved at a walking pace. However, an engineer named Raoul Hafner proposed an innovative solution: airlifting light vehicles using unpowered rotary wings, similar to those later used in helicopters. His concept involved towing the vehicle, behind a truck or light aircraft until lift off. Once airborne, it would be released, and the pilot would use autorotation to fly the vehicle to the landing zone. A prototype was built and tested, but with the advent of larger gliders, the project was ultimately abandoned.

The experimental Hafner Rotabuggy. Source: www.macsmotorcitygarage.com

An Airborne Dilemma

With the abundance of US-supplied military vehicles, the British sought ways to incorporate them into various roles, and experiments. Among those interested was Raoul Hafner, a rotor kite enthusiast. Rotor kites were essentially unpowered rotary-wing aircraft that shared many design features with later helicopters. While helicopters can take off under their own power, rotor kites cannott, instead, they need to be towed by a larger aircraft, or a suitable ground vehicle. Once airborne, they rely on airflow over their rotary wings to generate lift and remain airborne. This can be achieved by descending to generate speed and lift, having a strong wind to keep the rotor wing turning, or remaining tethered to another vehicle for the entirety of the flight. Although this technology was inexpensive to build, it was never implemented on a larger scale.

Hafner was born in Austria in 1905. In his early twenties, he developed an early interest in rotorcraft design, and in 1928, he collaborated with Bruno Nagler on an early helicopter prototype. In the early 1930s, Hafner emigrated to the United Kingdom, where he began working on gyroplanes there, he designed and built a functional prototype known as the Hafner A.R.III Gyroplane. Hafner continued refining his designs, but with the outbreak of World War Two, he was briefly held in state custody due to his Austrian origin.

Raoul Hafner would go on to play a vital role in the history of helicopter development. However, his early work was primarily focused on an unpowered variant known as the rotor kite. Source: en.wikipedia.org

Upon his release, Hafner began working on a solution to Britain’s shortage of materials needed for parachute construction. His goal was to develop an inexpensive, one-man rotor kite to carry an infantryman deep behind enemy lines. The core principle behind his concept was that, given the scarcity of materials required for parachute production, a small, easy-to-build, and simple-to-control rotor kite could serve as a cost-effective alternative. These kites were designed to be towed into the air by another aircraft and then released near the designated target. Once released, the pilot/paratrooper would glide down slowly before proceeding to their objective. Hafner followed with a small prototype series of these aircraft, designated the Hafner Rotachute. While his work showed promise, it ultimately resulted in only a limited number of experimental prototypes, with no further large-scale implementation.

The so-called Hafner Rotachute was an experimental attempt to develop an alternative to parachutes. While the concept was intriguing, it never progressed beyond a small prototype production run. Source: en.wikipedia.org

He soon expanded on that idea, if he could devise a way to land soldiers, why not include light vehicles as well? Paratroopers, who were often dropped behind enemy lines to wreak havoc among key targets, were frequently left vulnerable as they were lightly armed and had limited mobility. The challenge, however, was that airdropping even light vehicles was no simple task. Hafner theorized that his rotor kite design could be expanded and enlarged to allow for the airlifting and deployment of light vehicles. If successful, this would provide paratroopers with a means of transportation, increasing their effectiveness in combat.

The overall design was intended to be as simple as possible. A standard light vehicle, left mostly unmodified, would be partially enclosed within an aerodynamic fuselage, likely made of plywood, to provide lift and protect the crew from the tow aircraft’s propeller wash, and the wind. A rotary assembly would be mounted on top, while a large tail section at the rear would ensure lateral stability. Upon landing ,assuming a safe descent, the crew would discard the fuselage, leaving the vehicle fully operational and ready for use without issue.

In 1942, with this idea in mind, he approached the Central Landing Establishment, later renamed the Airborne Forces Experimental Establishment, to present his proposal. While, at first, the concept of attaching a makeshift rotary wing to a lightweight wheeled vehicle may seem dangerous and wasteful, it would be phenomenally valuable should it succeed. Developing an effective method for transporting such vehicles over long distances would have provided significant combat advantages. This was especially crucial at a time when the Allies were considering various plans and strategies for invading occupied France, plans where airborne units played a star role. Thus the Central Landing Establishment saw potential in this idea, and Hafner received approval to move forward with its development. Now, Hafner needed to find a suitable light chassis for the job. Fortunately for him, he didn’t have to search for long, the answer was already in the hands of the UK’s ally across the Atlantic.

A Well-Known Icon

In the 1930s, the leadership of the US Army closely observed the rapid military developments unfolding in Europe and the Pacific. In response, the Army sought to modernize its forces, starting with an increase in mobility for its reconnaissance units and couriers, which at the time primarily relied on horses.

Initially, as in Germany, motorcycles were introduced for this role. While they were an improvement over horses, they had significant limitations, primarily their limited carrying capacity, as they could only transport the driver, one additional passenger, and a very small amount of cargo. It became clear that a larger, more capable vehicle was needed.

This led to the  development of small, relatively inexpensive, all-wheel-drive light vehicles. Throughout the 1930s, the Army conducted extensive testing and evaluation of several different designs. After these trials, a final decision was made to adopt Willys-Overland Motors’ design, known as the Willys MB, but generally, it was simply referred to as the  Jeep, as the Army’s standard lightweight reconnaissance vehicle. Unbeknownst to them at the time, they had just created one of the most iconic military vehicles in history.

The Willys MB would become one of the most iconic military vehicles in history. Source: en.wikipedia.org

While Willys was set to produce these new vehicles, the immense demand and the need to utilize the vast production capacity of its competitor, Ford, led to the company also receiving orders to manufacture the vehicle. Although Ford was allowed to make some modifications, the overall design had to remain to ensure all mechanical components for the vehicles were interchangeable. Between 1941, when production began, and 1945, over 600,000 of these vehicles were produced. They saw widespread service across the globe during and after the war, with a significant number still in use today.

Initially designed for reconnaissance operations, their sheer numbers and popularity led to their adaptation for various roles. These included medical evacuation, combat, self-propelled rocket launchers, and long-range raiders for missions against enemy rear positions. They were also used as command vehicles, among many other roles.

The vehicle was widely exported to Allied nations, including the UK, which received tens of thousands. Even the Soviet Union acquired them and eventually developed its own variant. Given the vast stockpile of these vehicles, it is unsurprising that Hafner chose to test his idea using one of them.

The Jeep saw extensive use by British special forces in North Africa, where it played a crucial role in raids targeting enemy rear positions. Source: wikipedia.org

Name

The unusual vehicle was known by many nicknames. It received the Air Ministry designation ML 10/42 Special Rotating Wing Glider. It was also called the Malcolm Rotaplane, Flying Jeep, and Blitz Buggy. Eventually, it became best known simply as the Hafner Rotabuggy. For the sake of simplicity, this article will refer to it as the Rotabuggy.

Building and Testing the Vehicle

After receiving approval, the next task was to find a suitable chassis, and someone capable of building the vehicle or aircraft. Given the abundance of options, Hafner decided to utilize the US-supplied Jeep light reconnaissance vehicle. For the construction of the working prototype, he approached R. Malcolm Ltd., a small company that had been building aircraft components during the war.

Once the base components were selected, the construction of the working prototype began. It was likely completed by mid-1943. The first flight trials of the Rotabuggy were scheduled for November 1943. These trials were planned to be conducted using a Diamond T 4-ton 6×6 truck as a tug vehicle. This was seen as a simple, cost-effective, and safe option, given the prototype’s early development stage, far too early for tests with aircraft. The flight tests were carried out on the 16th November, 1943. Despite numerous attempts, the crew was unable to get the Hafner Rotabuggy off the ground, as they could not achieve the necessary speed to generate lift.

The Rotabuggy’s shape in its early experimental phase was still evolving. Experimenting with the design led to many changes, such as the introduction of much larger tail fins. Source: www.nevingtonwarmuseum.com

Further tests were carried out on 27th November. This time, a stronger, albeit unspecified, tug vehicle was used. The initial test was successful, as they managed to lift the Rotabuggy into the air. The first flight test using a tug aircraft, specifically a Whitley Bomber, was conducted in December 1943. However, the first design problems were identified during this test flight. At a speed of 80 km/h (50 mph), the vehicle experienced strong vibrations, forcing an early end to the flight.

Subsequent tests with a similar tug vehicle showed that the vibrations persisted at speeds of 70 km/h (45 mph) and higher. Additionally, during one test flight, one of the rotors struck the tail fin, damaging it in the process. Following these tests, the Rotabuggy was temporarily grounded for various repairs and modifications.

By February 1944, the Rotabuggy achieved a speed of 112 km/h (70 mph), and many more tests were carried out throughout 1944. On September 11th, 1944, the first major test flight was undertaken. At a height of 120 m (400 feet), after being towed by a Whitley bomber, the small buggy was released. After some brief difficulty controlling the aircraft, the pilot managed to land the vehicle, though with some effort.

In later stages, it would look visually much different, having a fully enclosed cockpit. Source: www.macsmotorcitygarage.com

Fate

Given the extensive testing, it was clear that there was significant interest in this project. However, despite more than a year of development, the project was ultimately canceled. The primary reason for this was not the new concept itself but rather the fact that the British had begun mass-producing gliders, such as the Waco CG-4, which could carry a Jeep within its fuselage. As a result, the Rotabuggy was no longer needed.

While his Rotabuggy project reached an unsuccessful dead end, this was not the end of Hafner’s story. Given his expertise in rotor aircraft development, he was appointed Chief Designer and head of the newly established Helicopter Division at Bristol. Hafner’s work at Bristol was highly successful, and he played a pivotal role in advancing early British helicopter design. His contributions were instrumental in the development of aircraft such as the Type 171 Sycamore, and the large tandem-rotor Bristol Belvedere.

He was also among the first aircraft engineers to receive the Dr. Alexander Klemin Award, a prestigious honor in the field of vertical flight aeronautics. Tragically, in 1980, Hafner disappeared at sea when his boat went missing and was never found.

Technical characteristics

The Rotabuggy fuselage was an extension added to the U.S. Jeep, designed to enable controlled flight. During testing, it was concluded that the Jeep could be dropped from a height of up to 2.35 m (7.7 ft) without suffering any major mechanical breakdowns. It could thus theoretically survive rough landings on unprepared ground.

Essentially, it consisted of a standard Jeep with four metal bars arranged in a pyramidal shape at its base. To enhance structural integrity, two additional metal bars connected the front and rear pairs. Atop this framework, a rotor unit was intended to be installed.

Another metal frame was attached to the rear section, consisting of at least four long stringers reinforced with smaller crossbars. Surrounding this structure, a series of almost circular frames, decreasing in size toward the tail section, were added to shape the fuselage.

A clear view of the Rotabuggy’s internal framework, which consists of at least four long stringers reinforced with smaller crossbars and enclosed in a plywood skin. Source: www.macsmotorcitygarage.com

The structure forming the base of the fuselage was then covered with plywood for aerodynamics. The sides and top were essentially flat, without any noticeable features. Large windshields were added at the front and on the crew’s side doors, providing excellent, almost all-around visibility. This gave the crews a clear view, more than sufficient for landing the aircraft. While little data for its flight characteristics survive, its estimated rate of sink at a speed of 77 km/.h (48 mph) was 4.9 m/s (960 ft/min)

Large windshields were added at the front and on the crew’s side doors, providing excellent, almost all-around visibility. This gave the crews a clear view of their surroundings. Source: rafbeaulieu.co.uk
The rear part of the fuselage was essentially flat, featuring only a slight curve. Source: /www.nevingtonwarmuseum.com

To help provide lateral stability, a large tail assembly was added to the vehicle’s rear. It consisted of two fairly large vertical stabilizers. Interestingly, there were no rudders on these fins. Lastly, a small landing skid was located at the end of the vehicle’s tail.

 

The tail assembly features two large fins that provide much-needed lateral stability. Source: www.nevingtonwarmuseum.com

The crew consisted of two members: a driver and a pilot. The driver was seated on the left side, as in the original Jeep configuration. The pilot sat in the opposite seat and was responsible for controlling the rotor blades, which were used to lift the vehicle off the ground. To control the vehicle, the pilot was provided with a control column, a rotor tachometer, and a set of basic and glider navigational instruments. Once on solid ground, the vehicle would be driven like a regular Jeep.

The Rotabuggy used rather long rotor blades, with a diameter of 14.22 meters (47 feet). There were some issues with this length, as on at least one occasion, they damaged the rear tail assembly, luckily without injuring its crew.

The control column for the aircraft. Source: aviadejavu.ru
The Rotabuggy used rather long rotor blades. There were some issues with this length, as on at least one occasion, they damaged the rear tail assembly. Source: aviadejavu.ru

Surviving Aircraft

Since it never progressed beyond the prototype stage, it is not surprising that the vehicle did not survive to the present day. The prototype was eventually refurbished back to a standard Jeep . However, being such an intriguing design concept, a replica was built by the Wessex Aviation Society. can now be seen at the British Museum of Army Flying in Middle Wallop, Hampshire.

While the prototype did not survive, the Wessex Aviation Society managed to modify a Jeep and create a modern replica of the Hafner Rotabuggy. Source: www.reddit.com

Conclusion 

The Hafner Rotabuggy was surely an interesting and unique attempt at utilizing the relatively new rotorcraft design. In theory, this concept would allow for an alternative method of airdropping men and materials, including vehicles.

While the Rotabuggy had some issues, such as severe vibration during flight, it was generally considered a mechanically sound design. However, its main drawback was that, despite its novelty, it did not offer significant improvements over the gliders already in use. As stronger and more capable gliders were developed, which could transport both personnel and lightweight vehicles, the Rotabuggy became obsolete.

Although its service life was short, the project played a vital role in shaping Hafner’s future work in rotary-wing aircraft, ultimately contributing to the development of various helicopter designs.

Hafner Rotabuggy  Specifications
Length 2.9 m / 9  ft 6 in
Height 2.06 m / 6  ft 9 in
Main rotor Area 15.9 m² /  173 ft²
Engine None / ( 60 hp in Jeep)
Empty Weight (for Jeep only) 964 kg / 2,125lbs
Maximum Takeoff Weight 1,411 kg / 3,110 lbs
Maximum estimated speed 241 km/h / 150 mph
Cruising estimated speed 130 km/h / 80 mph
Crew Two – The pilot and the driver
Armament
  • none

Illustration

 

Credits

  • Article written by Marko P.
  • Edited by  Henry H.
  • Illustration by Oussama Mohamed “Godzilla

 Source:

   

Boulton Paul P.75 Overstrand

UK, WW2, ,

United Kingdom (1933)

Medium Bomber – 28 Built

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.

Boulton Paul P.75 Overstrand Specifications
Wingspan 71 ft 11 in / 29.2 m
Length 46 ft 1 in / 14.3 m
Height 15 ft 9 in / 4.8 m
Wing Area 979.5 ft² / 91 m²
Engine 2x 580 hp ( 426 kW ) Pegasus II.M.3 9-cylinder radial engines
Propeller 2x 4-blade metal propellers
Weights
Empty 8004 lbs / 3630.6 kg
Loaded 11392 lbs / 5167.3 kg
Climb Rate
Time to 6500 ft / 1981 m 5 minutes 24 seconds
Maximum Speed 153 mph / 246.2 km/h at 6,500 ft / 1981 m
Range 545 mi / 877 km
Maximum Service Ceiling 21,300 ft / 6490 m
Crew Crew of 4

1x Pilot

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 Sidestrand
Overstrand 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.

PB.29E & PB.31E Supermarine Nighthawk

Great Britain, WW1, ,

UK Union Jack United Kingdom (1915 & 1917)
Anti-Airship Fighter – 1 Each Built

Supermarine PB.31E Nighthawk

In 1915, Germany began bombing Great Britain by Zeppelin. For the first time, Britain itself was under threat by enemy aircraft. Early attempts to counter the Zeppelins were ineffective. The Royal Air Corps needed an aircraft to be able to endure long, nighttime missions to chase the Zeppelins. The Pemberton-Billing aircraft company designed the PB.29E quadruplane for this task. The aircraft didn’t perform as hoped, but before a final conclusion could be made it was lost in a crash. Years later in 1917, with the company under new management and renamed Supermarine, the program would rise again as the PB.31E.  The PB.31E was dubbed the Nighthawk, and like its predecessor, proved to be ineffective in the role. The fighter is significant for its unusually large quadruplane layout and the first aircraft to be built by Supermarine.

History

The arrival of the Zeppelin in 1915 as a new type of weapon was an unwelcome one. It offered a new way of strategic bombing, as Zeppelins were faster and able to ascend higher than aircraft at the time. Zeppelins also served as a weapon of terror, as the civilians of England had never been faced with anything like it before, especially since the Zeppelins attacked mainly at night. Early attempts to counter Zeppelin raids proved ineffective, as anti-aircraft guns had a hard time spotting and aiming at the Zeppelins. Early forms of countermeasures involved aircraft dropping flares to illuminate the Zeppelins for gunners to see. None of these aircraft were used to actually intercept the airships. The Royal Air Corps needed an aircraft that would be able to reach and pursue Zeppelins on the homefront and on the battlefield. A potential solution came from a man named Noel Pemberton Billing.

Noel Pemberton Billing (1881-1948)

Noel Pemberton Billing was a man of many talents. He was an inventor, aviator, and at one point a member of Parliament. At the time, he was invested in many forms of new technology and aircraft was one of them. Having formed his own aircraft company in 1913, he built several aircraft types for the Royal Naval Air Arm (RNAA), such as the PB.25. He had taken a short break from designing planes for the RNAA and wanted to pursue aircraft to help in the war effort. The task of taking on Zeppelins got him interested in designing a plane to fill the role.

His answer was the PB.29E, a quadruplane aircraft. Information regarding the PB.29E is sparse and no specifications can be found for it. To get the aircraft to the altitudes at which Zeppelins usually lurked, Pemberton Billing applied triplane principles in making the aircraft, except taking it a step further and adding an extra wing. Having more wings, in theory, would assist with lift, a necessary factor when trying to chase the high-flying Zeppelins. Work began in late 1915, with the aircraft being finished before winter. The PB.29E was intended to fly for very long missions and needed to operate at night. To assist in spotting the behemoths, a small searchlight was to be mounted in the nose of the aircraft. The sole PB.29E crashed in early 1916. From test flights, the aircraft proved to be cumbersome and would not have been able to pursue Zeppelins. The two Austro-Daimler engines did not prove to be sufficient for the intended role, and performance suffered from it.

German Navy – R Class Zeppelin L 31

On September 20th, 1916, Noel Pemberton Billing sold his company to Hubert Scott Paine so he could become a member of Parliament. His career in Parliament was full of slander and conspiracy, and ultimately negatively affected the war effort. Soon after being acquired, Paine renamed the company as the soon to be famous Supermarine Aviation Works, in honor of the firm’s telegraph address. Work continued on a Zeppelin interceptor, which would eventually become the PB.31E. The PB.31E was technically the first aircraft built by Supermarine and it resembled a larger and more advanced version of the PB.29E. It retained many aspects from its predecessor: the quadruplane layout, the mounted searchlight, and endurance for long nighttime missions. The armament was expanded with a second Lewis gun mounted in the rear cockpit as well as a Davis gun mounted on top of the cockpit above the wings. To make the crew more comfortable, the cockpit was fully enclosed, heated, and had a bunk for crewmembers. The Austro-Daimler engines were replaced by 100hp Anzani radial engines. Expected speed was 75 mph (121 km/h) and it was to operate up to 18 hours.

The design team poses in front of the newly completed Nighthawk, fourth from the left is R.J Mitchell.

The aircraft was constructed in February of 1917, with a second in the works. On board the project was R.J Mitchell, the future designer of the Supermarine Spitfire. He began as a drafstman for the company and several designs concerning the fuselage and gun mounts of the PB.31E are labeled with his name. To the engineers, the aircraft was dubbed the Supermarine Nighthawk, however, this name was never official. Early flights were conducted at the Eastchurch airfield by test pilot Clifford B. Prodger. Tests showed that, like its predecessor, the engines weren’t capable of propelling the aircraft to its desired level of performance. To reach altitudes most Zeppelins were found at took an hour. Not to mention, newer Zeppelins could go even higher. Its expected 75 mph (121 km/h) top speed was never reached, with the aircraft only going 60 mph (96 km/h). However, it had a safe 35 mph (56 km/h) landing speed, which would have given the aircraft easy landing capability. With the performance lacking, the RAC deemed the project to be a dead end.

With the introduction of new incendiary rounds which easily ignited Zeppelins, Britain could defend itself with the improved AA guns. Along with the new rounds, the RAC started using the Royal Aircraft Factory B.E.2 to intercept Zeppelins at night. Originally intended for dogfighting, the B.E.2 proved to be ineffective and slow against fighters, but Zeppelins were easier, and much larger targets. With the Nighthawk now not needed, Supermarine ended up scrapping the first and incomplete second prototypes in 1917. Although the Nighthawk would never have been successful had it entered production, it still represents major innovations in aircraft design. It was one of the first true night-fighting aircraft to be designed, a concept later heavily utilized in the Second World War. The honor of being the first aircraft built by Supermarine under their name also goes to the Nighthawk.

Design

Overhead and side schematic views of the PB.29E

The PB.29E was a quadruplane designed to chase and intercept Zeppelins. Its fuselage was mounted between the lower two wings, with a gunner port being mounted in the upper two wings, leaving an opening in the middle between the two. Two crewmembers occupied the central fuselage with a single gunner gunner position in a seperate section above. The cockpit was open to the elements, as well as the gunner port. For armament, a single Lewis gun was mounted for attacking Zeppelins. For engines, the PB.29E had two Austro-Daimler six-cylinder engines in a pusher configuration. The tail itself was doubled.

Schematics for the Nighthawk with R.J Mitchell’s initials.

The PB.31E was a quadruplane like the PB.29E, but it was larger utilized a different fuselage design. Instead of having the fuselage between the lower two wings, the PB.31E positioned its body between the middle two wings. The body itself was of all wooden construction. To reduce splinters if the aircraft was fired upon or in the event of a crash, the fuselage was taped and covered in heavy fabric. To make the long missions more comfortable the cockpit was heated and completely enclosed by glass. A bunk was added for one crew member to rest during the flights as well, as the expected flights could last up to 18 hours. A searchlight mounted protruding from the center of the nose for use in patrols at night. The searchlight was movable to allow pointing it at different targets. It was powered by an onboard dynamo hooked up to a 5hp A.B.C petrol engine. For fuel storage, the PB.31E had 9 individual petrol tanks located around the cockpit area. The tanks were built to be interchanged if they were damaged or empty. In the front of the aircraft were several slits behind the searchlight that would assist in cooling. The wings of the PB.31E had significant cord to them. The tailplane was doubled like on the PB.29E, and the tail itself was lower to allow the rear mounted Lewis gun more range

The newly completed PB.29E, the gunner position between the two topmost wings is easily visible

of fire. For engines, the PB.31E had two Anzani radial engines in tractor configuration. These engines gave the PB.31E its slow speed of 60 mph (96 km/h), and its hour-long ascent to 10,000 ft (3000 m). The fluid lines, controls and other parts connected to the engines were placed outside the fuselage in armored casings. For armament, the PB.31E carried a frontal Lewis gun, a top mounted Davis recoilless gun and a rear Lewis gun. The Davis gun was built on a mount that allowed an easy range of motion in most directions. Lewis gun ammo was stored in six double cartridges and 10 Davis gun rounds were stored onboard as well.  Also on board were an unknown amount of incendiary flares to be dropped should a Zeppelin be directly below the craft.

Variants

  • 29E– First aircraft built for the Anti-Zeppelin role. Armed with a single Lewis gun. Crashed during testing.
  • 31E– Second aircraft. One prototype and one unfinished plane. Resembled a larger version of the PB.29E. Carried a Davis gun and two Lewis guns. Scrapped once the design was deemed unworthy.

Operators

  • Great Britain – The two prototypes were built and tested in England.

Supermarine PB.31E Nighthawk Specifications
Wingspan 70 ft / 18.29 m
Length 36 ft 11 in / 11.24 m
Height 37 ft 9 in / 5.4 m
Wing Area 962 ft² / 89 m²
Engine 2x 100 hp ( 76kW ) Anzani Radial Engines
Weights  

Empty 3677 lbs / 1667 kg
Loaded 6146 lbs / 2788 kg
Climb Rate  

Time to 10,000 ft / 3047 m 60 minutes
Maximum Speed 75 mph / 121 km/h
Cruising Speed 60 mph / 96 km/h
Landing Speed 35 mph/ 56 km/h
Flight Time Up to 18 hours of continuous flight
Crew 3-5 Crew

1 Pilot

2-4 Gunners
Armament ●      2x 7.7mm Lewis Guns

●      1x 1 ½ Pounder Davis Gun (10 rounds)

●      1x Frontally-mounted Searchlight

●      Unknown amount of incendiary flares

 

Gallery

Side profiles by Ed Jackson – www.artbyedo.com

Pemberton-Billing PB.29E
Supermarine PB.31 Nighthawk
The PB.29E under construction in Woolston
A frontal view of the PB.29E, note the searchlight
The newly constructed Nighthawk sits in a hangar at Woolston
The Nighthawk on the runway, notice the weapons and spotlight are absent

Sources

 

 

Sopwith Triplane N6290 Dixie - Side Profile View

Sopwith Triplane

Great Britain, WW1, , , , , , ,

british flag Great Britain  (1916)
Fighter Plane – 147 Built
The Sopwith Triplane was a creation of Britain’s Sopwith Aviation Company around 1916. Its three stacked wings gave it good maneuverability and stability in flight relative to other planes of the day. The aircraft had the nicknames Tripehound, Trihound, Triplehound, or Tripe and it was popular among pilots. The Triplane first saw service with Royal Navy Air Squadron No.1 in late 1916. Many orders were placed by the RNAS as well as the Royal Flying Corps. Some aircraft were also acquired by the French Navy. One each was sent to Greece and Russia for evaluation. Only two original examples of the Tripe exist today.

Design

Sopwith Triplane Blueprint - Front ViewThe most noticeable aspect of the Triplane is its three wing design, which was one of the first of its kind. In the interest of pilot field of view Chief Engineer Herbert Smith decided to use a narrow chord design, meaning the wings were short as measured from leading edge to trailing edge. Because of the lift lost when narrowing the chord, the third wing was added to the design. All three wings have functional ailerons and the tailplane is a variable incidence type which means it can be trimmed enough for the pilot to fly hands-off. In early 1917 a smaller tailplane was introduced improving maneuverability. The Triplane was fitted with a single Vickers gun.

The Tripehound

Sopwith Triplane Flying

WIth the Tripehound’s entry into active service late in 1916, it quickly proved popular among pilots with its relatively superior maneuverability and speed. The first adversaries the Tripehound went up against were German Albatros D-IIIs which it greatly outclassed in climbing and turning ability, as well as being 15 mph faster. Every engagement with the enemy demonstrated the Triplanes’ superior power.

Clerget Power

Clerget 9 Cylinder Engine HeadThe Triplane was powered first by a Clerget  9B, 9 cylinder rotary engine developing 110 HP (82 kW). This powerplant was built in both France and Great Britain by numerous manufacturers. Later, 130 HP 9B engines were fitted, further enhancing the Triplane’s dominance, although the engine was tuned perhaps too aggressively as it was prone to overheating.

 

 

Sopwith Triplane Specifications
Wingspan  8.07 m / 26 ft 6 in
Length  5.73 m / 18 ft 10 in
Height  3.20 m / 10 ft 6 in
Wing Area 11 m² / 118.4 ft²
Engine 1 air-cooled Clerget 9B 110 HP or 130 HP
Maximum Take-Off Weight 698 Kg / 1,541 lb
Empty Weight 499 kg / 1,101 lb
Maximum Speed 188 km/h / 117 mph
Range 2 hours and 45 minutes
Maximum Service Ceiling 6,248 m / 20,000 ft
Crew 1 (pilot)
Armament 1 synchronized 7.7mm Vickers machine gun

Gallery

Sopwith Triplane Prototype N500 Side Profile View
Sopwith Triplane Prototype N500 – June 1916
Sopwith-Triplane-Prototype-N500-Brown-Bread-Side-Profile-View
Sopwith Triplane Prototype N500 – June 1916 repainted as “Brown Bread”
Sopwith Triplane N5387 Peggy - Side Profile View
Sopwith Triplane N5387 “Peggy” – August 1917
Sopwith Triplane N533 Black Maria - Side Profile View
Sopwith Triplane N533 “Black Maria” – July 1917
Sopwith Triplane N6290 Dixie - Side Profile View
Sopwith Triplane N6290 “Dixie”


Simulated Dogfight in a Triplane

Sources

1 Franks, N. (2004). Sopwith Triplane aces of World War 1. Oxford: Osprey., Images:Sopwith Triplane Flying at Duxford 2012 by Airwolfhound / CC BY-SA 2.0 , Clerget 9B Engine Head by Andy Dingley / CC BY-SA 3.0