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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:

   

Fw 189C 

Weimar and Nazi Germany, WW2, , , , , , , ,

Nazi flag Nazi Germany (1939)

Close-support ground attack aircraft : Two prototypes built

The Luftwaffe (Eng. German Air Force) entered the Second World War without a dedicated close air support aircraft, with their more infamous dive bombers carrying out their missions independently of ground forces. As this need became increasingly apparent, attempts were made to identify a suitable design, but any new aircraft would have to be as inexpensive as possible, as other aircraft projects were prioritized. With limited options, Focke-Wulf proposed adapting its Fw 189 reconnaissance aircraft for this role. While promising in theory, the adaptation proved flawed and ultimately unsuccessful in practice. Despite this, two prototypes were built and tested, but by 1940, the project was abandoned.

The Unsuccessful Ground Attack Variant of the Fw 189. (Source: planehistoria.com)

A Modern Reconnaissance Aircraft

The rise of Nazism in Germany during the 1930s led to a massive military buildup, defying the limitations imposed by the Treaty of Versailles, which by this time was little more than a formality, with few parties motivated to uphold it. Among the most rapidly expanding branches was the Luftwaffe, which received substantial investment and development, leading to the introduction of a series of modern aircraft designed for various military roles.

One of these roles, tactical reconnaissance, was initially assigned to the Henschel Hs 126. Despite its somewhat outdated design, this high-wing aircraft proved reasonably effective for its intended purpose. However, its relatively low speed and the absence of a dedicated observer limited its effectiveness in reconnaissance missions.

Even as the Hs 126 entered service, the Reichsluftfahrtministerium (RLM), or German Air Ministry, took steps to develop a more advanced replacement. In 1937, they initiated a program to explore new designs. Although multiple projects were tested, the Focke-Wulf Fw 189, headed by the engineer Kurt Tank, ultimately emerged as the chosen design.  While RLM officials were initially uncertain about the Focke-Wulf proposal, they eventually placed an order for three prototypes. Construction on the first prototype designated the Fw 189V1, began in April 1937 and was completed in 1938. It was soon followed by two additional prototypes.

As preparations for production were underway, the RLM initially decided to rely solely on the Hs 126. However, after the successful conclusion of the Western campaign against the Allies in France in June 1940, Luftwaffe officials reconsidered their stance on the Hs 126. It became evident that this aircraft would soon be extremely obsolete in its intended role, necessitating an urgent search for a replacement. The only aircraft that could potentially fulfill this role within a short timeframe was the Fw 189. Production began in the summer of 1940, and by 1944, fewer than 900 units of this aircraft had been built. Despite the limited production, the Fw 189 saw extensive service and proved to be both popular and highly effective throughout the war.

The first Fw 189V1 prototype. (Source: wikipedia)

A Modern Air Force With No Ground Attack Aircraft?

While the rearmament of the German military forces was underway, Luftwaffe officials recognized the need for a dedicated ground-attack aircraft to provide close air support. Although the Ju 87 Stuka was designed for precision bombing to neutralize fortified targets, it was clear that they needed a heavily armed and well-protected aircraft for close-in support near friendly units. Despite this need, early Luftwaffe development in this area lagged, for reasons that remain unclear. Kurt and his team at Focke-Wulf saw a potential business opportunity and decided to repurpose their Fw 189 aircraft to meet this demand.

Recognizing that the Fw 189’s glazed, unarmored fuselage was not equipped for the ground-attack role, the Focke-Wulf team set out to develop a more protected fuselage design, which would house both a pilot and a rear gunner. Eager to proceed quickly, Focke-Wulf engineers decided to modify the first prototype of the Fw 189. The aircraft was returned to the Focke-Wulf factory in 1938 so that work on the modifications could begin immediately. After several months of redesign and construction, the new prototype designated Fw 189V1b (later marked with the code NA+BW) was completed and underwent its first flight tests in 1939. It was powered by the two 430 hp Argus As 410 engines.

The results of these tests were disappointing, to say the least. The prototype was difficult to control, and its overall flight performance was poor. The added weight significantly affected its handling and maneuverability. Furthermore, the small armored glass windshield provided a limited view for the pilot, making it challenging to fly. To make matters worse, the rear gunner’s visibility was almost nonexistent.

Only two prototypes of this variant would be constructed. (Source: planehistoria.com)

With few other options, the aircraft was returned to Focke-Wulf for further modifications. Both the pilot’s and rear gunner’s visibility issues had to be addressed, necessitating adjustments to the overall design. After a series of modifications, the aircraft was deemed ready and submitted to the Luftwaffe for evaluation. Despite the promise of close-support ground attack aircraft, it attracted little interest from major German aircraft manufacturers, leaving the Henschel Hs 129 as its only real competitor.

After a series of test flights with both aircraft, Luftwaffe officials grew increasingly annoyed and disappointed.  The Fw 189 and the Hs 129 performed quite poorly. As a result, both aircraft were sent back for further improvements. However, the story of the Fw 189V1b came to an abrupt end shortly after this competition. During one demonstration flight, the pilot miscalculated his approach and collided with a building while attempting to land. Although he survived with injuries, the prototype was so severely damaged that it was written off entirely.

Future Development 

Despite a rough start, the project was not abandoned. Though the initial prototype failed, it still held interest with some Luftwaffe officials, leading to an order for Focke-Wulf to produce another prototype for further testing. Expectations were high, as this version was intended to enter production as the Fw 189C and to have corrected all the faults of the disappointing first attempt. To meet these demands, Focke-Wulf developed the Fw 189V6 prototype, which carried the code D-OPVN.

In appearance, the Fw 189V6 closely resembled the previous model, but it featured a slightly modified fuselage and was powered by a more powerful 465-horsepower Argus As 410 engine. The prototype was completed and tested in 1940, with trials conducted by the 5 Staffel of Lehrgeschwader 2. During testing, pilots who had the chance to fly both the Fw 189V6 and its competitor, the Henschel Hs 129, overwhelmingly favored the Focke-Wulf design.

However, the pressures of the ongoing war and reduced production capacity meant that the Luftwaffe needed an option that was quicker and cheaper to mass-produce. Ultimately, the Hs 129 was chosen, despite its reputation as a more cumbersome design. The fate of the Fw 189V6 is unclear, though it was likely scrapped. The close support role was later taken up by the Fw 190, with special fighter bomber variants being created to take up the mission and phase out the dated dive bombers.

The Fw 189V6 prototype was to serve as the base for the anticipated C variant, but in the end, nothing came of it. (Source: www.airwar.ru)

Although the Fw 189C never entered production, some Fw 189A models were modified for ground-attack roles during the war. Designated as the Fw 189A-4, these variants were armed with two forward-mounted 20 mm cannons and two MG 17 machine guns. Additional armor was installed to protect vital components, including the fuel tanks, engines, and fuselage. An unknown number of these modified aircraft were produced starting in late 1942.

Technical characteristics

The Fw 189C prototypes incorporated several components from the original Focke-Wulf design. The original glazed fuselage was replaced with a fully enclosed, two-man armored compartment. This updated cockpit featured an armored, pointed nose, designed to provide an improved forward view while maintaining some degree of aerodynamic efficiency. The canopy had three small windows, and directly behind it was a compact compartment for the rear gunner. The aircraft’s overall construction consisted of rounded metal frames covered with a stressed duralumin skin. The new fuselage was reinforced with armor plating, though specific details about the placement and thickness of the armor are not mentioned in available sources. Unfortunately, the design proved to be cramped and lacked consideration for the comfort of both the pilot and the gunner.

The aircraft’s wings consist of two primary sections: a central, square-shaped segment connecting the nacelles and engines, and an outer section extending from the booms. The wing structure has a steel spar framed by duralumin, while the ailerons and split flaps are covered in fabric. At the rear, the twin-tail assembly includes two large rudders connected by a single, extended elevator, with both tail control surfaces also being fabric-covered.  Since the wing root was designed to support heavy armament, the central part of the wing had to be reinforced to withstand the recoil forces.

The first prototype was powered by a  430-horsepower engine, while the second prototype featured 465-horsepower Argus As 410 A-1, both 12-cylinder air-cooled engines. Unfortunately, specific details about the aircraft’s flight characteristics were not mentioned in available sources. It is known, however, that the added weight of the armor and armament degraded its flight performance, though the extent of this impact remains unclear.

The main landing gear extended from beneath each engine nacelle, with smaller wheels extending from the rear tail assembly. Later in the war, the second prototype received reinforced landing gear to improve durability.

As it was intended for ground attack operations, the second prototype was armed with two 20 mm MG 151/20 cannons and four 7.92 mm MG 17 machine guns. For rear self-defense, a dual MG 81 machine gun mount was installed. Had it entered production, it is likely that bomb racks would have been added

Close up view of the Fw 189’s experimental fuselage. (Source: www.airwar.ru)
Top view of the new fuselage with the canopy removed. (Source: www.airwar.ru)
The two prototypes were provided with single-leg landing gear. (Source: www.airwar.ru)

 

Conclusion

The Fw 189C was an intriguing attempt to develop a ground-attack aircraft based on the successful reconnaissance version. While it performed effectively in its original reconnaissance role, the ground-attack variant proved far less successful, proving cumbersome and difficult to fly. Only two prototypes were ever built before the project was discontinued in 1940, with the Hs 129 deemed a more cost-effective alternative.

Fw 189C (Estimated) Specifications
Wingspans 18.4 m / 60 ft 4 in
Length 12 m / 39 ft 5 in
Height 3.1 m / 10 ft 2 in
Wing Area 38m² / 410 ft²
Engine Two 465 hp Argus As 410A-1 engines
Crew pilot, rear gunner
Armament
  • Two 2 cm MG 151.20
  • Four 7.92 mm MG 17
  • And two 7.92 mm MG 81

Illustration

Credits

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

Source:

  • D. Donald (1996) German Aircraft of World War II, Orbis Publishing
  • D. Nesic  (2008)  Naoružanje Drugog Svetsko Rata-Nemacka
  • D. Monday (2006) The Hamlyn Concise Guide To Axis Aircraft OF World War II, Bounty Books
  • J. R. Smith and A. L. Kay (1972) German Aircraft of the WW2, Putnam
  • G. Punka (1993) Focke-Wulf Fw 189 in Action, Signal Publication
  • Captain E. ‘Winkle’ Brown (2010) Wings of the Luftwaffe, Hikoki Publication
  • https://vintageaviationnews.com/warbirds-news/unique-focke-wulf-fw-189-offered-for-sale.html

 

 

Fw 189A

Weimar and Nazi Germany, WW2, , , , , , , , , , ,

Nazi flag Nazi Germany (1940)

Type: Reconnaissance aircraft

Number built: 864

In the late 1930s, the Luftwaffe received substantial resources which allowed for the development of many new series of aircraft. While the Luftwaffe would take on numerous new roles in the new modern military, reconnaissance of enemy territory would remain a crucial aspect of their operations. This reconnaissance work involved identifying weak points and reporting any enemy activity which could prove threatening to the situation on the ground, or presented an opportune target for the air force. The primary responsibility for these tasks fell to light, tactical reconnaissance aircraft. Initially, the Hs 126 was chosen for this role, early combat experience revealed the need for a modern replacement. This led to the development, and introduction, of the well-known twin-engine Fw 189, designed by Kurt Tank.

Fw 189A was Germany’s first modern tactical reconnaissance aircraft. Source: www.luftwaffephotos.com

History

Following the rise of the Nazi party in Germany, significant investments were made in both the Army and the Airforce. The latter, in particular, experienced rapid expansion, through the introduction of a series of new aircraft designed to fulfill various roles. This was no easy task for the Germans, as following the end of the First World War, they were prohibited from developing new aircraft. As a result, they essentially had to start from scratch. For short reconnaissance flights, the Hs 126 was selected. Despite its outdated appearance, this high-wing parasol aircraft proved to be well-suited for the role. However, it was not without flaws.

As production began, the first aircraft of this type was field-tested during the Spanish Civil War. While it performed excellently in its intended role, two major issues were identified. First, the rear gunner also served as the observer, requiring him to switch between these roles depending on the combat situation. The gunner/observer’s primary responsibility was to act as a vigilant lookout, constantly scanning for potential threats while simultaneously surveying the battlefield. This dual role required sharp focus and the ability to quickly assess and respond to emerging dangers, and naturally proved challenging. Second, the aircraft’s low speed, while beneficial for reconnaissance, made it vulnerable to enemy fighters. Essentially, a third crew member was needed, along with an increase in speed, to address these shortcomings.

The Hs 126 was chosen as the Luftwaffe’s first operational tactical reconissance aircraft. Source: en.wikipedia.org

The initial deployment of the Hs 126 in Spain quickly demonstrated to the Germans that the aircraft would soon become obsolete. In response, the Reichsluftfahrtministerium, or German Air Ministry, issued a request for a potential replacement in February 1937. The requirements were straightforward: the new aircraft needed to accommodate a crew of three, provide excellent all-around visibility, achieve a higher maximum speed, and carry an improved defensive armament. Additionally, the RLM decided to include a bomb rack capable of carrying at least 200 kg, reasoning that it would be advantageous to drop bombs during reconnaissance missions.

Three companies reached the final stage of this competition: Arado with the Ar 198, Focke-Wulf with the Fw 189, and Blohm & Voss with the BV 141. Among these, only the Ar 198 had a conventional design by the standards of the time. The Fw 189 featured a central glazed nacelle flanked by two tail boom-mounted engines. The BV 141, however, stood out with its highly unconventional asymmetrical design.

The Arado entry to this competition, the Ar 198. Source: en.wikipedia.org
Blohm & Voss’ asymmetrical BV 141. Despite its unusual design, the aircraft performed surprisingly well, but did not enter mass production. Source: en.wikipedia.org

The Focke-Wulf design team, led by renowned German aircraft designer Kurt Tank, and supported by E. Kosel conceived a twin-boom aircraft powered by two engines. The central section featured a large, fully enclosed, and heavily glazed fuselage. They also proposed that the aircraft could be adapted for various roles by simply using different fuselage sections. The paper proposal and calculations were completed quickly and presented to the RLM in February 1937. Although the RLM officials were initially uncertain about the Focke-Wulf design, they eventually placed an order for the construction of three prototypes. Interestingly, when the request for a potential replacement for the Henschel Hs 126 was issued, there was no specification that the aircraft had to be powered by a single engine.

Work on the first prototype, designated Fw 189V1 (D-OPVN), began in April 1937. This aircraft was powered by two 430-horsepower Argus As 410 engines. By 1938, the prototype was ready and underwent flight testing by Kurt Tank himself in July of that year. The prototype demonstrated excellent performance and had no major issues.

The first prototype, Fw 189V-1. Source: en.wikipedia.org

The second prototype, designated D-OVHD, was flight-tested in August 1938. It was used to test the installation of armaments, including machine guns and bombs. Two 7.92 mm MG 17 machine guns were mounted inside the wings, one (or possibly three, depending on the source) machine gun was installed in the aircraft’s nose, one in the dorsal position, and another in the cone-shaped turret at the rear of the fuselage. Four bomb racks were also added under each wing, each capable of carrying up to 50 kg of bombs. If necessary, the aircraft could be equipped with chemical containers filled with either poison gas or smoke.

A third prototype, designated D-ORMH, followed and was flight-tested in September 1938. This variant was essentially a direct copy of the previous two but without armament. It was primarily used for testing the installation of Argus automatic variable-pitch propellers.

All three prototypes demonstrated excellent overall performance, while their competitors were less fortunate. The Ar 198 was quickly eliminated from consideration due to its poor performance, with only one prototype ever built. RLM officials were uncertain about the next steps, as both the Fw 189 and BV 141 were unconventional designs that were considered unproven. It is not far-fetched to suggest that the RLM had concerns about whether the BV 141 could even be flown reliably in field conditions, leading them to favor the Fw 189 instead. As a result, Focke-Wulf received a production order for four additional prototypes.

Anticipating a major production order, the fourth prototype (D-OCHO) was designated as the basis for the first production variant, named the Fw 189A-0. This variant was powered by two more powerful Argus As410A-1 engines, each producing 465 horsepower. The armament was reduced to just two machine guns.

While Focke-Wulf was making plans for the potential production of the first Fw 189A-0 aircraft, the company’s officials were disappointed and shocked when the RLM informed them that the Hs 126 would not be replaced by the new Fw 189. The Luftwaffe had changed its mind, deciding that the Hs 126 did not, in fact, need to be replaced.

Finally, into the production

Despite its potential, Focke-Wulf could do little to advance the design at the time given the news from the Luftwaffe. Not wanting to waste a promising project, Kurt Tank and his team continued working on it at a slow pace, and at low cost. However, following the successful conclusion of the campaign in France in June 1940, Luftwaffe officials reassessed their opinion on the Hs 126. It became clear that this aircraft was obsolescent in its intended role, and an urgent replacement was needed. The only available aircraft that could potentially fill this role in a short time was the Fw 189.

As a result, Focke-Wulf received its first production order for 10 Fw 189A-0 models in the summer of 1940. The company was also instructed to proceed with the development of the A-1 variant, which was to enter production as soon as possible. However, Focke-Wulf was already heavily involved in the development and production of the new Fw 190 fighter, making it difficult to meet the demands for the Fw 189.

To expedite production, an aircraft manufacturer in Prague was contacted to assist with manufacturing. Even this was not sufficient, so Focke-Wulf moved the production of the Fw 189 to France, utilizing several captured aircraft manufacturing facilities. The Focke-Wulf factories in Bremen and the Aero factories in Prague ceased Fw 189 production in late 1942 and 1943, respectively. Production continued in the French factories until January 1944, when it was finally halted.

The production by years was as follows.

Year of Production Production numbers 
1939 6
1940 38
1941 250
1942 327
1943 226
1944 17
In total  864

 

Main Production Variants 

The A-series was based on the V4 prototype. Unlike the prototype series, it did not include the nose-mounted machine guns. Instead, its main armament consisted of two machine guns mounted in the front wing roots, with an additional one or two located at the rear. If needed, a bomb rack could be installed. Given the aircraft’s specific reconnaissance roles, it could be equipped with various types of cameras. The A-1 model was essentially a direct copy of the fourth prototype, with slight modifications made to the engine cowling to enhance its aerodynamic profile.

The V4 prototype served as the base for the Fw 189 A-0 series. Source: www.warbirdphotographs.com
Early produced Fw 189A-1 aircraft. Source: Pinterest

At least 30 Fw 189A-1 aircraft were modified for use as night interceptors for use against slow, low flying biplanes on the Eastern Front. To fulfill this role, they were equipped with a FuG 212 C-1 aerial interception radar, distinguished by its forward antenna. Additionally, a fixed MG 151 cannon, either 1.5 cm or 2 cm in caliber, was installed in the rear, angled upward to target enemy aircraft from below.

One of the 309 Fw 189A was modified to be used as a night interceptor. They can be easily identified by the front-mounted antenna and the rear MG 151 cannon. Source: www.warbirdsresourcegroup.org

Combat experience quickly revealed that the Fw 189 needed a stronger defensive armament. In response, the Fw 189V9 prototype was tested with the installation of two twin 7.92 mm MG81Z (Z stands for Zwilling – twin) mounts. As these proved reliable, they were adopted for the A-2 variant, which entered production around mid-1941.

Shortly after its introduction into service, it became evident that a dual-control training variant was necessary to properly train pilots. Since the B variant did not enter mass production, a solution was required. The most cost-effective option was to modify an existing Fw 189A with dual controls. This led to the creation of a small production series of training aircraft, designated as the A-3. Some of the older aircraft from the A-0 and A-1 series, as well as prototypes, were repurposed for this variant.

The A-4 was designed as a light ground-attack variant. It was armed with two forward-mounted 20 mm cannons and two MG 17 machine guns. Additionally, armor was added to protect vital components such as the fuel tanks, engines, and central fuselage. An unknown number of these variants were produced beginning in late 1942.

A few aircraft adapted for the African theater of war were equipped with dust filters and designated as the Fw 189A-1 Trop.

Nicknames

Interestingly, Kurt Tank himself nicknamed this aircraft Eule (Eng. Owl). Allegedly, the inspiration for this name came from the large, owl-like shape of the cockpit. The RLM media referred to it as Das Fliegende Auge (Eng. The Flying Eye), while those who operated it on the front lines called it Uhu (Eng. Eagle Owl).

In Combat

During 1940, the first produced Fw 189 aircraft were allocated to various Luftwaffe experimental and training units. Their purpose was to test and evaluate the new Fw 189’s performance. For example, the Lehrgeschwader 2 (Eng. Training Squadron) was supplied with five Fw 189A-0 aircraft, which were flight-tested against the Hs 126. After a series of evaluation flights, the Fw 189 was declared superior in all aspects. This conclusion was a key reason why Luftwaffe officials decided to adopt the Fw 189.

Due to the slow pace of production, when the war with the Soviet Union broke out in June 1941, only about 250 Fw 189s were available for service. This number was barely enough to outfit all units, so the Hs 126 had to remain in use.

By 1942, the Fw 189 began gradually replacing the Hs 126 as the main German tactical reconnaissance aircraft. According to German records from September 1942, out of 317 short-range reconnaissance aircraft, 174 were Fw 189A-1 and A-2 models.

Their service on the Eastern Front demonstrated that these aircraft, despite their seemingly fragile appearance, were quite robust and capable of withstanding heavy damage. For example, on the 19th  May  1942, a lone Fw 189 was attacked by Soviet fighters near the Taman Peninsula. The left engine of the Fw 189 sustained such severe damage that it fell off. Assuming the aircraft was doomed, the Soviet fighters broke off the attack. However, the pilot did not give up and managed to fly the damaged Fw 189 back to German lines, where he executed an emergency landing. The aircraft suffered additional damage during the crash landing, yet it was eventually repaired and returned to service. Despite their durability, several Fw 189s were lost, along with other equipment, during the encirclement of German forces at Stalingrad. In one unusual incident, a Soviet fighter pilot, after running out of ammunition, rammed a Fw 189 near Stalingrad, successfully severing its tail.

By 1943, the Soviet Union’s increased fighter production made short-range operations too dangerous even for the Fw 189. Reconnaissance missions became nearly impossible without a fighter escort. After 1943, the Fw 189 was primarily employed for ground attack operations against Soviet Partisan positions, achieving notable success. However, with the Soviet fighter force continually growing, the days of the Fw 189 were numbered. By 1944, it was rarely used in its original reconnaissance role and often became a priority target for Soviet fighters once spotted. Despite this, the aircraft remained effective in some areas, such as Finland, where it continued to be used until September 1944.

The Fw 189 was primarily operated on the Eastern Front, including Finland. The only other front where it saw limited use was in North Africa. A small number of night interceptor variants, some 30, were assigned to two units, Nachtjagdgeschwader 5 and 100 (NJG, or Night Fighter Squadron), and served late into the war. Tasked specifically with countering Soviet Po-2 biplanes that harassed German railroad lines, NJG 100 earned the nickname Eisenbahn-Nachtjagd (Eng. Railway Night Hunt). The Fw189 performed excellently in this role, bringing down many Soviet night bombers in the process.

Beyond its original role, the Fw 189 also saw service as a light bomber and VIP staff transport. For example, the A-1 variant was used as a personal transport for Field Marshal Albert Kesselring. By late 1944, most of the surviving Fw 189 aircraft were relegated to training duties.

Despite their modest numbers, the Fw 189 would see extensive use on the Eastern Front. Source: www.asisbiz.com
Near the end of the war, the few surviving Fw 189 were used as training aircraft, easily identified by the large painted number on their tails. Source:. G. Punka Focke-Wulf Fw 189 in Action

Failed Proposals 

Although the Luftwaffe initially did not adopt the A variant, they showed an interest for the crew training variant designated as the Fw 189B. This version featured a less-glazed fuselage and dual control units. However, only a small number of these variants were produced.

The Fw 189B variant. Source: /www.warbirdsresourcegroup.or

The first year of the war revealed that the Germans lacked a dedicated armored close support aircraft. In response, Focke-Wulf proposed the Fw 189C as a potential solution. This variant featured a small, cramped, but well-protected cockpit, replacing the previous large fuselage. However, due to poor visibility and handling issues, it was not adopted for service.

The Fw 189D was proposed for naval use and was equipped with twin floats. It was essentially based on the Fw 189B variant, but no further developments materialized.

Focke-Wulf also experimented with various engines. The Fw 189E was tested with the French GR14M 700 hp engine. Unfortunately, the prototype was lost in an accident while being transported from France to Germany in 1943. The Fw 189F, based on the A-2 variant, was powered by the As 411MA-1 600 hp engine and used to test electrically powered landing gear. Although the tests were successful, only 17 units were built in 1944 before the production of the Fw 189 was discontinued.

The Fw 189F-2 was an improved version with enhanced armor protection, but it did not progress beyond the proposal stage. The last proposed variant, the Fw 189G, was intended to be powered by As 402 950 hp engines, but it also failed to materialize.

Other operators 

During the later stages of the war, the Hungarians received over 28 Fw 189 aircraft. Despite the relatively small number of planes, these were used extensively by Hungarian forces. The Slovakians also received 14 Fw 189A-1s between 1942 and 1943, which were employed in the Crimea. Some surviving aircraft were even used against the Germans during the failed Slovakian uprising in late 1944, with at least six managing to escape to the Soviet Union. Bulgaria received several Fw 189s, which were deployed on the Eastern Front. Additionally, eleven Fw 189s were supplied to Romanian forces, primarily for training purposes, but most were eventually captured by the Soviets. After the war, one aircraft was operated by the RAF for evaluation purposes, but it was lost in a storm while being stored.

Hungarian operated Fw 189. Source: G. Punka Focke-Wulf Fw 189 in Action
A Soviet operated Fw 189, possibly one of the Slovakian managed to escape in late 1944. Source: www.luftwaffephotos.com
Smaller numbers were also allocated to the Bulgarian Air Force. Source: G. Punka Focke-Wulf Fw 189 in Action

After the war

When the war ended, there were few surviving Fw 189. The British managed to capture one in working condition. It was  extensively used by the British pilot Captain Eric Brown, who was the chief test pilot of the Royal Aircraft Establishment at Farnborough. He was involved in a British project tasked with taking over German war research installations and interrogating technical personnel after the war.

He was quite impressed with the overall performance of the Fw 189. After many hours of flying, he noted only one instance of engine failure. Even with just a single engine, the aircraft remained pleasant to fly without significant issues. The main drawback Captain Brown observed was the rather poor forward visibility, despite the extensive glass coverage in the front section. This limitation was primarily due to the shape of the nose. Nevertheless, Captain Brown described the Fw 189 as;

“… A Versatile little beauty to fly and a great asset to the German Army’s ground troop..”

Technical characteristics

The Fw 189 was designed as a twin-engine reconnaissance aircraft with a unique construction. Its centrally positioned fuselage featured extensive glazing and housed the cockpit at the front, followed by a small crew area and a gunner’s compartment at the rear. The fuselage was bulkier at the front and tapered toward the rear. Access to the crew area was provided through two hatches above the cockpit and a larger hatch at the rear. Although the extensive glazing left the crew more exposed to enemy fire, it was ideal for its reconnaissance role, offering excellent all-around visibility.

Font view of the Fw 189 pilot cockpit. Source: www.warbirdsresourcegroup.org
Side view of the glazed fuselage. Source: www.warbirdsresourcegroup.org
Access to the crew area was provided through two hatches above the cockpit and a larger hatch at the rear. Source: www.warbirdsresourcegroup.org

The wings are composed of two distinct sections. The central, square-shaped panel connects the nacelle and engines, while the second section extends outward from the booms. The wings feature a metal base covered with duralumin, though the ailerons and split flaps are clad in fabric. At the rear, the twin-tail assembly includes two large rudders, which are joined by a single long elevator. Both control surfaces on the tail are also covered in fabric.

 

A close-up view of the Fw 189 rear twin-tail unit. Source: www.luftwaffephotos.com

The aircraft was powered by two 465 hp Argus As 410 A-1 12-cylinder air-cooled V-12 engines. These engines demonstrated remarkable effectiveness and reliability, even under the harsh winter conditions of the Eastern Front. With these engines, the Fw 189 achieved a maximum speed of 335 km/h, though exact figures may vary between sources. Each engine drove a two-blade, constant-speed propeller. Fuel was stored in two 110-liter tanks, which were housed in the tail booms. The Fw 189 had a maximum operational range of approximately 670 km.

The landing gear consisted of larger road wheels positioned under each engine nacelle, with a pair of smaller wheels extending from the elevator. Initially, the aircraft used an ‘H’-shaped landing gear leg design, but this was modified during production. To enhance stability during landing, each landing gear leg was equipped with a shock absorber. The front landing gear units were lowered using hydraulic systems, while the rear smaller landing gear units descended under their own weight. When the aircraft’s speed dropped below 160 km/h, the landing gear automatically deployed in preparation for landing. If the pilot wished to override this action, they had the option to disable it by pressing a switch inside the cockpit.

The early prototypes had a single-leg landing gear unit. Source: www.luftwaffephotos.com
Later into production, these were replaced by more stable ‘H’ shaped landing gear legs. Source: www.luftwaffephotos.com

The aircraft’s crew consisted of three members: the pilot, the navigator, and the rear gunner. The pilot occupied the front of the cockpit, while the navigator sat directly behind him. In addition to navigation, the navigator operated the camera equipment and managed the upper rotating machine gun mount. He was also responsible for radio operations. The rear gunner, the final crew member, served as both machine gun operator and the flight engineer.

Most of the pilot’s instruments were were positioned near the cockpit roof, as shown here. Source: /www.luftwaffephotos.com

The primary armament of the Fw 189 consisted of two forward-mounted 7.92 mm MG 17 machine guns, operated by the pilot. The early design included a single machine gun in a rotating mount positioned on the dorsal side. A rear cone-shaped rotating turret housed additional machine guns, initially equipped with drum-fed MG 15s. These were later replaced by four belt-fed MG 81s, which offered a higher rate of fire. Additionally, the aircraft was equipped with two bomb racks under each wing, capable of carrying a 50 kg bomb or, alternatively, smoke gas or chemical containers though the latter were never actually used in combat.

The rear gunner operated a drum feed MG 15 or 17. Source:www.luftwaffephotos.com
These would be on A-2 variant replaced by two faster-firing MG 81 that were instead belt fed. Source: www.luftwaffephotos.com
A good view of the late improved twin machine guns in a rotating mount positioned on the dorsal side. Source: www.luftwaffephotos.com
The Fw 189 could also carry four 50 kg bombs. In this role as a light ground attack aircraft it achieved great success against Soviet partisans. Source: www.luftwaffephotos.com

For conducting reconnaissance operations, various camera equipment was utilized. Typically, an RB 20/30 camera was employed. However, depending on the specific task, this could be augmented or replaced by other models such as the RB 50/30, RB 21/18, or R.R 15/18. Additionally, the navigator was equipped with smaller handheld cameras. For communication, the FuG 25 radio was used.

Production Versions

  • Fw 189V– Small prototypes series
  • Fw 189A0 – Small pre-production series
  • Fw 189A-1 –  Main production variant
    • Fw 189A-2 – Improved model with better defense armament
    • Fw 189A-3 – Dueal control trainer, limited production only
    • Fw 189A-4 – Ground attack variant armed with two 2 cm cannons
  • Fw 189 Trop – A small number of aircraft modified for use in North Africa

Prototype and Proposed  Versions

    • Fw 189B – Trainer variant that was built in small numbers
  • Fw 189C – Ground attack variant, did not go beyond a prototype stage
  • Fw 189D -Experimental variant equipped with twin-floats,
  • Fw 189E – Powered by an As 411MA-1 600 hp strong engine. After the prototype was lost in 1943 the project was abandoned
  • Fw 189F-1 – Powered by an As 411MA-1 600 hp strong engines, A small series of 17 aircraft of this type were built in 1944
    • Fw 189F-2 – Slightly improved model, none were built
  • Fw 189G – Paper project powered by As 402 950 hp engines

Operators

    • Germany – Main use of this aircraft
    • Hungary – Operated less than 30 of these aircraft
    • Slovakia –  Received 14 Fw 189A-1s between 1942 and 1943,
    • Romania – Used an unknown number but mostly for training
  • Bulgaria –Opertaed 14 such aircraft
    • Soviet Union – The Red Army on occasion managed to capture some Fw 189 that they put into use
  • UK – British Force captured at least one working Fw 189 after the war

Surviving aircraft

It is believed that only one Fw 189 aircraft has survived to this day, and it has a remarkable history. The aircraft was shot down by Soviet fighters in May 1943 near Murmansk in northern Europe. It crash-landed in the woods, resulting in the deaths of the navigator and the rear gunner. The pilot, Lothar Mothes, survived the crash landing and managed to reach the German defense lines two weeks later. Although the Soviets recorded the crash site, they did not recover the wreckage. It remained there until 1992, when British aircraft enthusiast and restorer Jim Pearce initiated a recovery effort. Using a helicopter, Pearce salvaged the relatively well-preserved Fw 189 wreckage and transported it back to the UK for possible restoration.

The aircraft was publicly displayed at the Biggin Hill Air Show in 1996, where pilot Lothar Mothes had the opportunity to see his lost aircraft once more. Despite his hopes, Pearce was unable to secure the funds necessary for a full restoration, so the aircraft was sold to G. Allen’s Flying Heritage Collection in 2007. Over the following years, the aircraft underwent nearly complete restoration. Hopefully, one day, this sole surviving Fw 189 will once again take to the skies.

The only known Fw 189 that is being under restoration. Sourcewww.scramble.nl

Conclusion

Despite its unusual design, especially for the early stages of the war, the aircraft proved to be remarkable in many respects. Its glazed cockpit provided an excellent all-around view. The engine was reliable, with no major mechanical issues reported. Although it had a somewhat fragile appearance, the aircraft was noted for its robust performance.

Although originally designed for reconnaissance operations, the Fw 189 also proved successful in various other roles. In conclusion, the Fw 189 was undoubtedly one of the best German aircraft designs to see service during the Second World War.

Fw 189A-1 Specifications
Wingspans 18.4 m / 60 ft 4 in
Length 12 m / 39 ft 5 in
Height 3.1 m / 10 ft 2 in
Wing Area 38m² / 410 ft²
Engine Two 465 hp Argus As 410 A-1 engines
Empty Weight 2,805 kg / 6,185 lbs
Maximum Take-off Weight 3,950 kg / 8,708 lbs
Maximum Speed 335 km/h / 208 mph
Cruising Speed 315 km/h / 196 mph
Range 670 km / 416 miles
Maximum Service Ceiling 7,000 m / 22,965 ft
Crew pilot, rear gunner, and navigator
Armament
  • Four 7.92 mm machine guns
  • Four 50 kg (110 lb) bombs

Illustration

Credits

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

Source:

  • D. Donald (1996) German Aircraft of World War II, Orbis Publishing
  • D. Nesic  (2008)  Naoružanje Drugog Svetsko Rata-Nemacka
  • D. Monday (2006) The Hamlyn Concise Guide To Axis Aircraft OF World War II, Bounty Books
  • J. R. Smith and A. L. Kay (1972) German Aircraft of the WW2, Putnam
  • G. Punka (1993) Focke-Wulf Fw 189 in Action, Signal Publication
  • Captain E. ‘Winkle’ Brown (2010) Wings of the Luftwaffe, Hikoki Publication
  • T. Boiten () Nachtjagd Combat Archive – Eastern Front and The Med, Red Kite
  • https://vintageaviationnews.com/warbirds-news/unique-focke-wulf-fw-189-offered-for-sale.html

 

Source:  https://www.luftwaffephotos.com/#fightermenu

 

Me 261

Weimar and Nazi Germany, , , , , , , , ,

Nazi flag Nazi Germany (1938)

Type: High endurance experimental, reconnaissance aircraft

Number built: Three prototypes

Before the outbreak of the Second World War, the Luftwaffe (Eng. German Air Force) was undergoing a massive expansion. Numerous new aircraft designs were either being introduced into service or undergoing testing, with many being integrated into the military for various roles. A number of newly developed aircraft were also primarily used for evaluation and experimentation, and, there were also several designs created specifically to set records. One such aircraft, the Me 261, was built specifically at the request of Adolf Hitler to set long-range records. Due to its specialized role, and the fact that it was not initially ordered by the Luftwaffe, only three prototypes of the Me 261 were built.

The rather obscure Me 261 long-range transport and recconaissance aircraft. Source: alternathistory.ru

History

With the rise of Nazis in Germany, substantial financial resources were allocated to military projects. The Luftwaffe was founded, and saw massive expansion and the introduction of new aircraft designs. However, not all these designs were intended for pure military service. Some projects were mainly aimed at experimentation, and among these were aircraft designed solely to showcase technological advancements and break world records. This trend was quite common in the years leading up to the outbreak of the Second World War in Europe. For example, the Messerschmitt Me 209 was created to set a world speed record, with little to no concerns made over a possible military application.

Speed was not the only record to be pursued, there were others, such as long-range flight. This particular challenge fascinated Hitler, who in 1937, initiated the development of a long-range monoplane. Aside from the many things that might be learned from the experiment, Hitler envisioned this aircraft undertaking the long-range flight from Berlin to Tokyo for the 1940 Olympic Games, carrying the Olympic Torch from Germany over Asia. To meet this requirement, the initial requirements specified that the aircraft needed to have an operational range of over 13,000 km.

The Reichsluftfahrtministerium (RLM), or German Air Ministry, selected the Messerschmitt company for this task. Despite being a relatively small enterprise at the time, Messerschmitt had achieved great success with the Bf 109, one of the best fighters of its era. The official contract was signed on the 18th March, 1938. Under the designation P.1064, Messerschmitt presented a proposal to Hitler for a new aircraft. This aircraft was to be operated by a crew of five within a rather cramped, and elongated fuselage. Due to the aircraft’s specific role, the fuel load was prioritized over crew comfort. Hitler approved the proposal and ordered the construction of three prototypes. The project was subsequently renamed Me 261. Due to Hitler’s keen interest, the aircraft was nicknamed Adolfine by its crew.

In 1939, work began on the three Me 261 prototypes. Despite Hitler’s ambitions, the Me 261 was given low priority, and construction proceeded slowly, and anticipating a war with Poland, work on these aircraft was halted. However, recognizing its potential for long-range reconnaissance and the valuable information it could provide, work resumed in 1940.

The first prototype, Me 261 V1 (BJ-CP or BC-CP, depending on the sources), was flight-tested by Karl Baur in December 1940. The following year, the second prototype, Me 261 V2 (BJ-CQ), was tested. The V2 featured a glazed observation dome on the dorsal fuselage, replacing the rear dome used on the V1. The construction of the third prototype, Me 261 V3 (BJ-CR), faced delays and only completed its test flight in 1943. This version was distinct from the earlier prototypes, featuring a larger crew capacity of seven and being powered by two 2,950 hp DB 610 engines. On the 16th April, 1943, Karl Baur conducted a ten-hour test flight with the V3.

 

The last of the Me 261 was the V3 prototype, which was powered by stronger engines. Source: airpages.ru

Technical characteristics

Unfortunately, since the Me 161 did not progress beyond the prototype stage. It was designed as an all-metal, long-range transport and later as a reconnaissance aircraft. The fuselage was slim but cramped, made of metal, and covered in duralumin.

The wings of the Me 261 were constructed using a metal frame with a single spar. They were then covered with flush-riveted, stressed-skin metal panels. Notably, the section of the wing closest to the fuselage had a thick profile, which tapered to the wingtips. This design was intentional, as it allowed for a large fuel storage area. The aircraft also featured a twin-rudder tail at the rear.

For its long-range flight operations, the Me 261 had a crew of five: a pilot, co-pilot, radio operator, navigator, and flight engineer. The pilot and copilot sat side-by-side in the cockpit with the radio operator in a central compartment, and the flight engineer and navigator seated in the rearmost compartment, where the aircraft’s bunks were also located.

The first two prototypes were powered by twin 2,700 hp DB 606A/B twenty-four-cylinder engines. These engines were essentially two twelve-cylinder DB 601 engines coupled together to drive a single shaft, requiring two separate radiators and oil coolers. Each DB 606A/B engine was housed within a large nacelle and used four-blade propellers with a diameter of 4.6 meters.

The Me 261 DB 606A/B twenty-four-cylinder engine consisted of two coupled twelve-cylinder DB 601 engines. They worked well on the He 261 and no major issue was reported with it. Source: oldmachinepress.com

Despite frequent mentions of the aircraft being overburdened, sources do not specify a consistent maximum takeoff weight. Additionally, the total fuel capacity is also unspecified. Depending on the sources, the operational range varies from 11,000 to 13,200 km.

To accommodate the aircraft’s weight, it required large-diameter landing wheels that could retract up to 90 degrees into the wings. In addition to these, it had a fully retractable tail wheel retracted towards the front of the aircraft.

The Me 261 was designed as an all-metal, long-range transport and later as a reconnaissance aircraft source: Wikipedia
The first two prototypes were powered by twin 2,700 hp DB 606A/B twenty-four-cylinder engines. To cope with their weight, it was provided with two large-diameter landing wheels. Source: planehistoria.com
Side view of the second prototype. Source:  alternathistory.ru

Fate

Despite demonstrating some potential for long-range reconnaissance, the Me 261 was ultimately rejected from service due to the additional equipment requirements that would have further strained its already overburdened airframe, thereby compromising its flight performance. Despite its cancellation, the V3 prototype (and possibly the other two prototypes) saw operational use as reconnaissance aircraft during the war. In July or April of 1943, the V3 suffered an accident during landing that heavily damaged its landing gear. Although repaired and returned to service, the V3 was eventually scrapped by order of the RLM.

The V1 aircraft was lost during an Allied bombing raid on the Rechlin test center in September 1944, while the V2 was captured by the Allies at the same location in April 1945. Neither prototype survived the war; the captured V2 was scrapped a few weeks after its capture.

The V3 aircraft was damaged during a landing accident but was repaired and put back into service. Source: www.destinationsjourney.com
The V2 was captured by the Allies and was eventually scraped. Source: planehistoria.com

Conclusion 

The Me 261 was an aircraft that was not ordered by the Luftwaffe as a military aircraft and thus received low priority. Despite its initial potential for use as a reconnaissance aircraft, it quickly became evident that it would not be feasible for adoption in this role due to its considerable weight. Ultimately, only three were built, and none of them survived the war.

Me 261 V3 Specifications
Wingspans 26.9 m / 88 ft 1 in
Length 16.7 m / 54  ft 9 in
Height 4.72 m /  15 ft  5 in
Wing Area 76 m² /  817.8 ft²
Engine Two 2,950 hp DB 610 engines
Endurance 24 hours and 36 minutes
Maximum Speed 620 km/h / 385mph
Cruising speed 400 km/h / 248 mph
Range 11,000 km / 6,831 miles
Maximum Service Ceiling 8,250 m  / 27,060 ft
Crew 1 pilot
Armament
  • None

Illustration

Credits

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

Source:

  • D. Herwig and H. Rode (2000) Luftwaffe Secret Projects Strategic Bombers 1935 to 1945, Midland Publishing
  • D. Nesić  (2008)  Naoružanje Drugog Svetsko Rata-Nemačka. Beograd
  • D. Monday (2006) The Hamlyn Concise Guide To Axis Aircraft OF World War II, Bounty Books.
  • J. R. Smith and A. L. Kay (1972) German Aircraft of the WW2, Putnam

 

ANT-2

Soviet, , , ,

USSR flag USSR (1923)
All-metal passenger aircraft – five Built

Following his successful first attempt to develop an aircraft, Andrei Nikolayevich Tupolev felt confident in his ability to attempt the design an all-metal aircraft. Although some European nations had already tested or built such aircraft during the First World War, this concept was still novel in the burgeoning Soviet Union of the early 1920s. With the advent of duralumin production in the Soviet Union, and the experimentation with various construction methods, Tupolev began work on the aircraft known as the ANT-2 in 1922. After a period of testing and evaluation, five aircraft of this type were constructed.

Tupolev ANT-2 was the Soviet first operational all-metal aircraft. Source: P. Duffy and A. Kandalov Tupolev The Man and His Aircraft

History

The success of the ANT-1 (standing for the initials of Andrei Nikolayevich Tupovlev) test aircraft prompted Tupolev to advocate for the development of fully metal-constructed aircraft. The harsh weather conditions in many parts of the Soviet Union caused wooden materials to decay quickly. Metal alloys, on the other hand, offered numerous advantages over wood: they were stronger, more durable, and allowed for overall more resilient aircraft designs. Tupolev saw the use of wood in modern aviation as an obsolete construction material.

His view was shared by others in the burgeoning Soviet aviation industry. In 1922, a commission at the Central Aero/Hydrodynamics Institute (TsAGI) was formed under the leadership of Andrei Nikolaevich. Its purpose was to spearhead the development of factories and facilities capable of producing duralumin. One such production center was already operating in Kolchuginsk, near Moscow, where the production of duralumin, nicknamed “Kolchugaluminium”, began in September 1922. This development enabled Tupolev to start working on an all-metal aircraft.

Tupolev established his design bureau with 15 supporting members. However, the initial phase was challenging, as the new technology required skilled workers who needed training in this new field. Additionally, many components used in all-metal aircraft construction had to undergo extensive testing. Tupolev, being a cautious man, did not want to risk any pilot’s life before he was certain that the new all-metal aircraft would perform as intended. Consequently, he spent considerable time refining various designs, mostly using speedboats and gliders. In 1921, Tupolev spent some time testing his ideas and designs using speedboats from his base of operations in Crimea. The experience he gained there greatly helped him in his further work.

Work On the ANT-2

As soon as Tupolev was sure that all crucial components were sufficiently tested, the work on the new all-metal aircraft, designated ANT-2, began in 1923. The design was largely driven by the requirements of the Soviet UVVS-RKKA (Directorate of the Air Fleet of the Workers and Peasants). This was the first official request for a new military aircraft, one capable of transporting two passengers, armed with two machine guns, and would most importantly, be inexpensive to build. Tupolev and his team established a small workshop in Kolchuginsk.

Initially, there were problems as the Kolchuginsk factory was only known for producing duralumin, not for shaping it into the various forms needed for aircraft construction. Time was needed to train the workers to effectively shape duralumin into the necessary parts.

During this period, while working on various proposed designs, Tupolev had the opportunity to inspect a Junkers K16 transport aircraft. The German company Junkers, wanting to avoid the sanctions on arms and aviation development imposed by the Allies, sought cooperation with the Soviets. They even managed to set up a small production plant in the Soviet Union.  The Soviets, in turn, were eager to acquire new technologies. The Junkers K16 featured a high wing and an open cockpit, design characteristics that Tupolev incorporated into his ANT-2 project.

The Junkers K16 served as inspiration for the ANT-2 Source: Wiki
The ANT-2, when compared to the K16, exhibits many similarities in overall shape. While Tupolev drew inspiration from the K16, he did not merely replicate it. Instead, he used it as a foundation to experiment with many of his own design elements, particularly in its wings. Source: en.topwar.ru

The prototype was completed in 1924 and underwent its first flight test in late May of that year, piloted by Nikolai Petrov. To simulate the weight of two passengers, two sandbags were used, as Tupolev did not want to risk any lives at the prototype stage. Further flight tests were conducted on May 28 by a Soviet military delegation. Starting from June 11, the ANT-2 was tested with two, and occasionally three, passengers inside its fuselage. Overall, the performance was deemed sufficient, though a significant modification was required for the rear tail assembly. The rudder and stabilizer size had to be increased, subsequently improving the aircraft’s performance. To conduct further tests, four more aircraft were built. By 1930, at least one of these aircraft was equipped with a more powerful 200 hp Wright Whirlwind engine.

Fate

A total of five ANT-2 aircraft were produced. While these were used for various tests, their specific operational roles are not well documented. The anticipated military variant, which was to feature a new cockpit positioned behind the wings and be armed with one or two machine guns, was never built. The first aircraft has been preserved and can be seen at the Aviation Museum in Monino, near Moscow. The fate of the remaining aircraft is unclear, but they were likely scrapped at some point.

The only surviving ANT-2 can be seen at the Aviation Museum Monino near Moscow. Source: Wiki
In recognition of its significant role in Soviet aviation history, the ANT-2 was featured on a Soviet postage stamp. Source: stock.adobe.com

Specification

The ANT-2 was designed as a high-wing, all-metal monoplane. Tupolev chose a triangular shape for the fuselage, with the sides sloping inward from top to bottom. This triangular design provided excellent structural integrity, reducing the need for additional fuselage struts. The fuselage was divided into three sections: the front section housed the engine, the open cockpit, followed by a small passenger compartment. The compartment could accommodate two passengers seated opposite each other. Although the aircraft was intended for three occupants, this was generally avoided due to weight limitations. Passengers entered the aircraft through a door on the left side of the fuselage.

The wing was located just behind the cockpit. It was constructed with two spars connected by 13 ribs on each side and covered with duralumin. Tupolev designed the wing with a curved, concave underside. The entire wing assembly was then attached to the top of the fuselage using four bolts. To accommodate the cockpit, part of the central section of the wing was cut off. Additionally, two handles were added to the ends of the wings on both sides, allowing the ground crew to maneuver the aircraft on the ground. The rear tail assembly consisted of a metal frame covered with duralumin.

The landing gear featured two fixed road wheels mounted on vertical struts, equipped with shock absorbers to ensure smoother landings. At least one aircraft was instead fitted with skis. A pivoting tail skid was used at the rear.

It was powered by a Bristol Lucifer three-cylinder engine producing 100 horsepower. With it a maximum speed of 170 km/h could be achieved. This engine, however, had some difficulties due to its significant torque, which could occasionally damage the engine mounts. Topolev, aware of this issue, designed a strong mount to counteract this problem. To allow access for repairs, the engine cover was secured with a few bolts. The engine drove a wooden two-blade propeller with a diameter of 2.2 meters. Fuel was stored in two 36 kg tanks located in the wings.

The cockpit was open, and to enter, the pilot used a small footrest on the left side of the fuselage. The cockpit was equipped with the basic and necessary controls and indicators, such as fuel level, RPM counter, and oil pressure gauge.

The ANT-2 was powered by a Bristol Lucifer three-cylinder engine producing 100 hp with a wooden two-blade propeller with a diameter of 2.2 meters. Source: Wiki
At least one aircraft was fitted with skis. Source: en.topwar.ru
The wings were constructed using two spars connected by 13 ribs on each side and covered with duralumin. Source:  en.topwar.ru
A good view of the real tail assembly. Source: www.valka.cz
The small passenger compartment was located inside the fuselage. Source: Wiki
Top view of the pilot’s open cockpit. Source:  en.topwar.ru

Conclusion

While the ANT-2 did not enter mass production, this was less important as it showed that the concept of using metal for the construction of a fully functional aircraft was feasible. It was the first stepping stone of the new, and slowly rising, Soviet aviation industry. It was the first such aircraft to be successfully tested by the Soviets, and paved the way for further Tupolev’s research and work, which enabled him to develop, in time,  more advanced designs. In addition, it was the first aircraft that was officially ordered by the Soviets for limited production.

ANT-2 Specifications
Wingspans 10.45 m / 34 ft 3 in
Length 7.6 m / 24 ft 11 in
Height 2.12 m / 6 ft 11 in
Wing Area 17.9 m²  / 193 ft²
Engine One
Empty Weight 523 kg / 1,153 lb
Maximum Takeoff Weight 837 kg / 1,846 lb
Maximum Speed 170 km/h / 106 mph
Range 750 km/ 466 miles
Maximum Service Ceiling 3,300 m / 10,926 ft
Crew 1 pilot
Armament
  • None

Illustration

 

Credits

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

Sources:

  • Duško N. (2008)  Naoružanje Drugog Svetsko Rata-SSSR. Beograd.
  • Y. Gordon and V. Rigmant (2005) OKB Tupolev, Midland
  • P. Duffy and A. Kandalov (1996) Tupolev The Man and His Aircraft, SAE International
  • B. Gunston () Tupolev Aircraft Since 1922, Naval Institute press

 

Me 309Zw (Me 609)

Weimar and Nazi Germany, , , , , , , ,

Nazi Germany (1944)

Proposed Fighter Design

During the war, Messerschmitt endeavored to find potential successors to their existing aircraft models. This quest yielded several aircraft proposals, one of which was the Me 309, which they sought to replace their older Me 109 fighter with. Despite Messerschmitt’s hopes for its success, the Me 309 proved to be unreliable and mechanically flawed, leading to its rejection for adoption. Undeterred by this setback, Messerschmitt persisted with the project, eventually turning their attention to a new twin-fuselage fighter, often referred to in various sources as the Me 609.

Artistic 3d model of the “Me 609” . Source: www.3dcadbrowser.com

A Brief History of Germany Twin-Fighter Program History

In the early stages of the war, the Messerschmitt Me 109 emerged as an exceptional fighter, arguably one of the world’s best at the time. However, despite its prowess, there remained ample room for improvement in its design. By the early 1940s, engineers at Messerschmitt began exploring avenues to enhance its overall flight performance. Among the considerations was the idea that while one engine delivered outstanding results, pairing two engines might yield even greater capabilities, bringing an increase in operational range and top speed. This notion laid the groundwork for a bold project: combining two Me 109s into a single aircraft, designated as the Me 109Z, with the ‘Z’ representing the German word “Zwilling”, meaning twin. The concept aimed to harness the power of dual fuselages and engines to significantly enhance both performance and firepower, envisioning the aircraft as either a formidable destroyer or a fighter bomber.

In theory, the design was relatively straightforward: merging two fuselages along with a central wing. The cockpit would be positioned within one of the fuselages, along with modifications to the landing gear. Despite the unconventional approach, a functional prototype utilizing two Me 109Fs was successfully constructed in 1942. However, the evaluation and test flight process extended until 1943, during which the prototype was either lost or severely damaged in one of the numerous Allied bombing raids.

Amidst the pressing demands of concurrent projects, such as the development of the Me 262, the Me 109Z initiative was ultimately abandoned, reflecting the shifting priorities and challenges faced by German engineers during the Second World War .

An Me 109Z drawing. Source: www.luft46.com

A Second Option 

Another Messerschmitt project aimed at enhancing the performance of the Me 109 was the Me 309. This new endeavor sought substantial improvements, integrating several new features such as enhanced armament, a pressurized cockpit, a tricycle undercarriage, and retractable radiators. Initiated by Messerschmitt in 1940, the project faced reluctance from the German Aviation Ministry (RLM), leading to significant delays. It wasn’t until the end of 1941 that actual work on the project began. Despite these challenges, the first Me 309 V-1 prototype was completed in June 1942, followed by a few more test models. However, the project encountered various mechanical issues that remained unresolved, including engine overheating, the problematic landing gear which caused the aircraft to crash onto its nose should the nose gear fail, and flight instability, among other issues. As a result, the RLM showed little enthusiasm for the Me 309, prioritizing increased production of the Me 109 instead. Introducing another fighter design would also inevitably lead to production delays. Moreover, refining the Me 309 design would likely necessitate additional time, possibly extending into months or even years. Consequently, a decision was made to abandon the development of the Me 309 entirely.

The Me 309 was an attempt to develop a completely new fighter to replace the Me 109. Given its many mechanical flaws, it did not go beyond the prototype stage. Source: /www.luftwaffephotos.com

However, Messerschmitt hoped that proposing a new variant of the twin-fuselage fighter based on the Me 309 might renew interest from the RLM. Unfortunately, this strategy didn’t yield the desired results. Despite some initial drawings, the aircraft designated as the Me 609 was abandoned at the beginning of 1944 in favor of the Me 262.

A drawing of the proposed “Me 609” aircraft. Source: D.Sharp Luftwaffe: Secret Designs of the Third Reich

Technical characteristics

Given that it was a paper proposal, and no working prototype was built, its overall technical specifications are rather obscure. In essence, the Me 609 consisted of paired Me 309 fuselages which were joined together by a central wing section. Given this fact, in theory, most of the components for this aircraft would be available and reused from the Me 309. The Me 309 was conceived as a single-seat fighter, featuring an all-metal construction with a low-wing design. So we can assume that the new Me 609 would also follow a similar construction.

The two fuselages were connected with the new inner wing section. Besides this, it also served to house the two main landing gear units. The nose wheel was located under the engine, and retracted to the rear. The pilot’s pressurized cockpit was located on the left fuselage, while; the right-sided fuselage had its cockpit covered.

The Me 309 used an unusual, at least for the Germans, tricycle landing gear unit. Source: www.luftwaffephotos.com

Depending on the source it was either powered by a  Daimler Benz 603 or 605 or a  2,000hp Jumo 213E june engine. In the case of the latter, the estimated maximum speed was to be 760 km/h. All of which were inverted V-12 engines.

The main armament was to consist of two 3 cm MK 108 and Two MK 103 cannons. Including either two 250 kg or one 500 kg bomb. Two more cannons could be mounted under the center wing section.

The Truth of it

The information as previously mentioned, however, may not be entirely accurate. According to various sources such as D. Herwing and H. Rode (Luftwaffe: Secret Projects Ground Attack and Special Purpose Aircraft), as well as several internet sources, it is asserted that the twin-fuselage Me 309 variant was designated as the Me 609. Contrary to this, D. Sharp (Luftwaffe: Secret Designs of the Third Reich) argues that this designation was incorrectly assigned to the project. The actual designation for it was Me 309 Zw (Zw standing for Zwilling, meaning twins). Claiming, the Me 609 was unrelated to this project. Sharp supports this assertion by citing surviving Messerschmitt documentation salvaged after the war, in which the projects are referred to as 309 Zw. Thus, the twin-fuselage fast bomber/destroyer based on the Me 309 existed only as a proposal, albeit under a different name.

Now, what about the aircraft bearing the Me 609 designation? Simply put, it did not exist. In reality, it was a designation that Messerschmitt applied to describe the Me 262 twin-engine fighter. Why this designation was used remains unknown, but it may have been employed to deceive the intelligence offices of the Western Allies

The evidence for the claim of the wrong designation lies in the old Messerschmitt documentation salvaged after the war. Here we can see the Me 262 which was for an unknown reason referred to as Me 609. Source: D. Sharp Luftwaffe: Secret Designs of the Third Reich

Conclusion 

The Me 309Zw project was an intriguing endeavor aimed at enhancing the overall performance of German fighters by integrating two fuselages. However, it failed to progress beyond the prototype stage, leaving us unable to determine its feasibility.

Me 309Zw Estimated Specifications
Wingspans 16 m / 52  ft 6  in
Length 9.52 m / 31 ft 2 in
Height 3.24 m / 10 ft  7 in
Wing Area 26.755 m² /  288 ft²
Engine Two 2,000hp Jumo 213E
Empty Weight 5,247 5kg / 11,660 lbs
Maximum Takeoff Weight 6,534kg / 14,520 lbs
Maximum Speed 760 km/h / 472mph
Crew 1 pilot
Armament
  • Two MK 108 and Two MK 103
  • Bomb load two 250 kg or one 500 kg

Illustration

 

Credits

  • Written by Marko P.
  • Edited by Henry H.
  • Illustrations by Oussama Mohamed “Godzilla”

Source:

  • D. Nesić  (2008)  Naoružanje Drugog Svetsko Rata-Nemačka. Beograd.
  • D. Monday (2006) The Hamlyn Concise Guide To Axis Aircraft OF World War II, Bounty Books.
  • J. R. Smith and A. L. Kay (1972) German Aircraft of the WW2, Putnam
  • D. Myhra (2000) Messerschmitt Me 209V1, Schiffer Military History
  • M. Griehl () X-planes German Luftwaffe prototypes 1930-1940, Frontline Book
  • D.Herwing and H. Rode (2002) Luftwaffe: Secret Projects Ground Attack and Special Purpose Aircraft, Midland
  •  D.Sharp (2018) Luftwaffe: Secret Designs of the Third Reich, Mortons

 

Me 309

Weimar and Nazi Germany, WW2, , , , , , ,

Nazi Germany (1943)

Fighter: Four prototypes Built

The Messerschmitt Me 109, although an outstanding aircraft, still had room for improvement. Its most noticeable shortcomings included a rather small operational radius, significantly reducing its combat potential in prolonged engagements. To address this, Messerschmitt initiated the development of a successor model designated as the Me 309. However, from the outset, this new fighter was plagued with numerous mechanical faults that could not be resolved in the foreseeable future. Consequently, only four prototypes were built before the project was ultimately canceled.

The Me 309 first prototype. Source: https://www.luftwaffephotos.com/lme2091.htm

History

At the onset of the Second World War, Germany relied heavily on the Me 109 as its primary fighter aircraft. Renowned for its exceptional performance and cost-effectiveness, the Me 109 outmatched most of the enemy fighters it encountered over Europe. Following the fall of France in June 1940, Germany launched a significant bombing campaign against the UK. This prolonged engagement highlighted a critical issue: the Me 109’s limited operational range prevented it from carrying out long-range fighter sweeps, or being usable as a bomber escort.

Recognizing the urgent need for enhancements, Messerschmitt began experiments on improving the performance, and range, of the Me 109. Initial assessments underscored the necessity for substantial improvements, including an 85% increase in operational range and a minimum 25% boost in maximum speed. Additionally, there were aspirations to augment its firepower, introduce a pressurized cockpit, implement a tricycle undercarriage, and incorporate retractable radiators. Before commencing work on a completely new fighter, Messerschmitt opted to experiment with these features by modifying an existing Me 109F

Some of the changes such as the tricycle undercarriage were first tested on one Me 109. Source: https://militarymatters.online/forgotten-aircraft/the-messerschmitt-me-309-redundant-beauty/

The new fighter project was initiated by Messerschmitt in 1940. However, the German Aviation Ministry (RLM) was not enthusiastic about it, after significant delays. Actual work on the project didn’t commence until the end of 1941. The project, designated Me 309, was led by Woldemar Voigt and Richard Bauer. It’s worth noting that Messerschmitt’s previous attempt to develop a fighter, based on the record-breaking Me 209, failed because its airframe wasn’t suitable for military purposes. Despite the RLM’s initial skepticism towards the Me 309, they eventually ordered nine prototypes.

The side view of the Me 209V1 prototype. While initially used as a speed record-breaker, Messerschmitt tried to adopt it for the military role but ultimately failed in this. Source: ww2fighters.e-monsite.com

The first Me 309 V-1 (GE-CU) prototype was completed in June 1942, and immediately underwent ground trials at the end of that month. However, almost from the outset, a major issue became apparent, the new landing wheel configuration proved difficult to control on the ground. Subsequent flight tests revealed additional challenges, including strong vibrations at high speeds. In July 1942, after a series of modifications, the prototype underwent flight testing once more, only to encounter new problems with the landing gear. The hydraulic retraction system was found to be inadequate, and issues with engine overheating and aerodynamic instability persisted. On one occasion, test pilot Karl Baur was forced to abort the flight after just seven minutes in the air.

Addressing these issues required further modifications, including redesigning the tailplane and improving the hydraulic system for the landing gear. Despite these efforts, subsequent test flights did not yield significant improvements in the overall flight performance of the Me 309. Messerschmitt’s test pilot, Fritz Wendel, expressed dissatisfaction with the aircraft, noting that its flight characteristics were not markedly superior to those of the Me 109. He criticized the high landing speed and the poor design of the control surfaces.

Not ready to abandon the Me 309 prematurely, the first prototype underwent evaluation at the Rechlin test center for further assessment. On the 20th of November 1942, a report was issued deeming the overall performance of the Me 309 unpromising, even inferior to the new Me 109G. Consequently, the RLM reduced the initial production order from nine prototypes to just four. Initially, the RLM had little enthusiasm for the Me 309, and still preferred instead to prioritize increased production of the Me 109. Introducing another fighter design would inevitably cause production delays. Compounding the industrial challenges, perfecting the Me 309 design would likely require additional time,  months if not years of work.

Despite these setbacks, the development of the Me 309 continued at a sluggish pace. The first prototype was initially equipped with a 1,750 hp DB603A-1 engine. It would later be replaced by a 1,450 hp DB 605B engine instead during the testing phase. During one landing, the front landing gear collapsed, causing the aircraft to nose down. Fortunately, the damage sustained was minor. However, the same couldn’t be said for the second prototype (GE-CV), which underwent flight testing on November 28, 1942. Upon landing during its maiden flight, the front landing gear failed, resulting in a hard impact on the ground. The force of the impact nearly split the aircraft into two parts, rendering it extensively damaged and subsequently written off. Despite this setback, two more prototypes were constructed during 1943.

The Me 309 had a troublesome landing gear and a tendency to flip over the nose. In one such accident, the second prototype was lost. Source: https://militarymatters.online/forgotten-aircraft/the-messerschmitt-me-309-redundant-beauty/

Technical characteristics

The Me 309 was conceived as a single-seat fighter, featuring an all-metal construction with a low-wing design. There is limited information available regarding its overall construction. The fuselage was of an oval shape, while the wings were characterized by a dihedral angle with rounded tips, accompanied by automatic leading-edge slots for better maneuverability at low speed. Notably, the wings also incorporated large flaps extending from the wing roots to the ailerons’ end. The canopy was fully glazed, affording excellent visibility of the surroundings.

There is some disagreement among available sources regarding the precise engine used in this aircraft. According to J.R. Smith and A.L. Kay in (German Aircraft of WWII) it was initially powered by a 1,750 hp DB 603A-1 engine, which enabled the Me 309 to achieve a maximum speed of 733 km/h at an altitude of 8,500 meters. This claim is supported by B.C. Wheeler in (Aviation Archive: German Fighters of WWII)  although Wheeler does not specify which DB 603 engine was used. On the other hand, Jean-Denis G.G. Lepage, in (Aircraft of the Luftwaffe) mentions that the Daimler-Benz DB 603G engine model was used, with the same maximum speed being achieved. The DB 603G is the likely most correct engine used on the Me 309, considering it was an experimental high-altitude model that never entered mass use.

The later prototypes were powered by a smaller 1,450 hp DB 605B engine. Even the first prototype was eventually reequipped with this engine. As a result, the overall performance dropped significantly to 575 km/h, according to D. Nesić (Naoružanje Drugog Svetsko Rata-Nemačka).

With a fuel capacity of 880 liters, its operational range extended to 1,400 km. Equipped with a retractable ventral radiator positioned under the fuselage, the aircraft’s landing gear retracted inward into the wings. A notable departure from convention was the absence of the standard tailwheel; instead, it featured a nosewheel, retracting rearward into the fuselage’s front section.

The Me 309 was initially tested with the DB 603A-1 engine with which it achieved a maximum speed of 733 km/.h. Source: http://www.luftwaffephotos.com/lme2091.htm
Rear view of the Me 309. Source: http://www.luftwaffephotos.com/lme2091.htm
The Me 309 incorporated some new features such as the new landing gear and a retracting radiator both of which can be seen here. Source: airpages.ru

Fate

Despite the considerable investment of time and resources into the Me 309 project, its overall flight performance fell short, ultimately leading to the project’s demise. By the beginning of 1943, the RLM had lost interest in the aircraft, prompting the cancellation of the project after the completion of four prototypes. Despite the cancellation, Messerschmitt proceeded to develop two additional prototypes.

One of these, the Me 309V-3 (CA-NK or CA-CW), was intended as a replacement for the lost V-2 prototype. Its maiden flight took place in March or April of 1943. The fourth prototype marked a significant milestone as it was the first to be equipped with offensive armament, including four 13 mm MG 131 (300 rounds), two 20 mm MG 151 (150 rounds), and two 30 mm MK 108 (65 rounds) cannons. Alternatively, it could be outfitted with two 15 mm MG 151 cannons and three 13 mm MG 131s. Although these armaments were primarily experimental and not used operationally, they were essential for various testing purposes.

Unfortunately, the fate of the last two prototypes remains unclear, with records suggesting they were lost during Allied bombing raids in 1944.

Despite the Messerschmitt hope the Me 309 would not be adopted for service, and the few built prototypes would be mainly used for various testing and evaluation. Source: http://www.luftwaffephotos.com/lme2091.htm

Even before the official cancellation, Messerschmitt officials were hopeful for a larger production order. To this end, they presented several variant proposals for the Me 309. The Me 309A was designed as a fighter variant, equipped with one MG 151 cannon and two MG 131 machine guns. The Me 309B was intended to serve as a fighter-bomber variant, armed with two 250 kg (550 lbs) bombs. As for the Me 309C, it was designed as a destroyer, featuring three MG 151 cannons and up to four MG 131s. An intriguing proposal was the Me 309 Zwilling (Eng. Twins), which involved two aircraft joined together in a configuration reminiscent of the post-war US F-82, but ultimately, this concept did not materialize.

A drawing of the proposed Me 309zw aircraft. Source: D.Sharp Luftwaffe: Secret Designs of the Third Reich

 

Interestingly in 1944 Japan expressed interest in its design and asked for plans and drawings of the Me309V-3 aircraft. But nothing came of this in the end.

Prototypes

  • Me 309V-1 – First prototype powered by a  1,750 hp DB 603A-1 engine
  • Me 309V-2 –  Second prototype lost during the first test flight
  • Me 309V-3 – This prototype was built in early 1943 as a replacement for the second prototype
  • Me 309V-4 – First prototype to be armed.

Proposed Variants

  • Me 309A – Proposed fighter variant
  • Me 309B – Proposed  fighter-bomber variant
  • Me 309C –Proposed destroyer variant
  • Me 309zw- Proposed twi-aircraft configuration

Conclusion 

The Me 309, despite the investment and the hope that it would be an adequate successor to the Me 109, proved to be a troubled design and pulled down by wartime pragmatism. From the start, it was plagued by various mechanical problems that were never resolved. The fact that RLM was never interested that much in such a project did not help either. As it would take considerable time to fully remediate all the noted issues, the project was abandoned in favor of the latter Me 262.

Me 309V-1 Specifications
Wingspans 11.04 m / 36  ft 2  in
Length 9.46 m / 31 ft 1 in
Height 3.4 m /  ft
Wing Area 16.55 m² /  178.08 ft²
Engine One 1,750 hp DB 603A-1
Empty Weight 3,530 5kg / 7,784 lbs
Maximum Takeoff Weight 4,250 kg / 9,371 lbs
Maximum Speed 733 km/h / 455 mph
Cruising speed 665 km/h / 413 mph
Range 1,400 km / 870 miles
Maximum Service Ceiling 12,000 m  / 39,360 ft
Climb to 8 km In 10 minutes
Crew 1 pilot
Armament

Illustration

Credits

  • Written by Marko P.
  • Edited by Henry H.
  • Illustrations by Oussama Mohamed “Godzilla”

Source:

  • D. Nesić  (2008)  Naoružanje Drugog Svetsko Rata-Nemačka. Beograd.
  • D. Monday (2006) The Hamlyn Concise Guide To Axis Aircraft OF World War II, Bounty Books.
  • J. R. Smith and A. L. Kay (1972) German Aircraft of the WW2, Putnam
  • D. Myhra (2000) Messerschmitt Me 209V1, Schiffer Military History
  • M. Griehl () X-planes German Luftwaffe prototypes 1930-1940, Frontline Book
  •  D.Sharp (2018) Luftwaffe: Secret Designs of the Third Reich, Mortons
  • Jean-Denis G.G. Lepage (2009) Aircraft Of The Luftwaffe, McFarland & Company, Inc
  • B. C. Wheeler (2014) Aviation Archive German Fighters of WWII, Kelsey Publishing Group

 

 

Messerschmitt Me 209A

Weimar and Nazi Germany, WW2, , , , , , , ,

Nazi Germany (1943)

Fighter: Four prototypes Built

Upon its introduction before the outbreak of the Second World War, the German Me 109 emerged as one of the premier fighter designs globally. While it proved formidable during the conflict, rival aircraft gradually matched and even exceeded its performance in several key areas. In a bid to secure a successor for the Me 109 late in the war, Messerschmitt endeavored to develop the Me 209A, a highly modified design based on its predecessor. Despite demonstrating promising flight attributes, logistical constraints hindered its adoption for active service.

The Me 209A Source: www.luftwaffephotos.com

History

While the Germans acknowledged the effectiveness of the Me 109, it became evident that a new fighter design, or serious enhancements to the existing model, would be necessary. In early 1941, Messerschmitt began developing a successor to the Me 109. This exploration resulted in the creation of the Me 309. It was a brand-new fighter aircraft that incorporated a new fuselage design, larger wings, and a tricycle undercarriage. It was powered by a 1,750 hp DB 603A-1. A few different armament systems were to be tested including four 13 mm MG 131 (300 rounds), two 2 cm MG 151 (150 rounds), and two 30 mm MK 108 (65 rounds) cannons. Alternatively, it could be outfitted with two 15 mm MG 151 cannons and three 13 mm MG 131s.

By June 1942, the prototype underwent flight testing. Despite an initially promising design, testing revealed that the Me 309 did not offer significant improvements over the Me 109G, which was already in mass production. Consequently, recognizing the impracticality of further investment, the Me 309 project was ultimately terminated.

The Me 309 was one of the Messerschmitt failed attempts to develop a successor for the Me 109. Source: www.luftwaffephotos.com

As the development of the Me 309 proved fruitless, Messerschmitt continued to strive towards a suitable replacement for the Me 109. Fortunately for the company, the German Air Ministry (RLM) initiated the development of a new high-altitude fighter on April 23, 1943. In response, Messerschmitt introduced the Me 209. Interestingly, this name was recycled from an earlier project, the original Me 209, which had been crafted specifically to set world-breaking speed records. However, it was ill-suited for military purposes and the project was ultimately shelved having fulfilled its original purpose. Despite this, Messerschmitt endeavored to develop a viable fighter based on the Me 209 but met with little success. To avoid potential confusion, the new project, which bore no resemblance to the record-breaking aircraft, was designated as the Me 209A (also occasionally referred to as the Me 209-II).

The Me 209 which had been crafted specifically to set world-breaking speed records, proved to be unsuited for fighter adaptation. Source: ww2fighters.e-monsite.com

In order to expedite development and minimize costs, the design of this new fighter used many components from the Me 109. A powerful engine was essential for achieving optimal flight performance. Thus, the prototype, powered by a 1,750 PS DB 603A-1 engine, underwent completion and testing in early November 1943, with Fritz Wendel as the pilot. To avoid confusion, it was designated as the Me 209V-5 (SP-LJ), distinguishing it from the original Me 209 prototypes, V-1 to V-4.

The success of the first prototype led to the completion and testing of a second prototype by the end of 1943, both exhibiting impressive flight characteristics. Encouraged by this achievement, construction of another prototype commenced. However, due to shortages of the DB 603A-1 engine, the decision was made to utilize the 1,750 hp Jumo 213E instead. This third prototype underwent flight testing in May 1944, prompting a designation change to Me 209A. The prototypes, with their alternate engine configurations, were then distinguished with the suffixes A-0, A-1, and A-2 for the first, second, and third, respectively.

Technical characteristics

Unfortunately given the obscurity of this project, its overall technical specifications are somewhat ambiguous. What is known is that it incorporated some 65% of its construction from the Me 109G. The original Me 109 fuselage was a monocoque design that was divided into two halves. These halves would be placed together and connected using simple flush rivets, thus creating a simple base on which remaining components, like the engine, wings, and instruments would be installed.

In order to accommodate the retracting landing gear, Messerschmitt deliberately opted for a single wing spar positioned towards the rear of the wing. This spar needed to be robust enough to withstand the flight’s load forces. The wings were attached to the fuselage by four sturdy bolts, simplifying the overall wing construction and reducing production costs. The Me209A boasted a larger wingspan and area, consequently increasing wing loading by 25% compared to the original Me 109. Furthermore, alterations were made to the wings and tail to address the Me 109’s strong yaw forces on takeoff. Whether these adjustments successfully rectified the issue in the Me 209A remains unclear according to available sources.

Initially, it was powered by a 1,750 hp DB 603A-1 engine which was provided with an annular radiator and a three-blade propeller. With this engine, a maximum record speed achieved was 724 km/h 450 mph at an altitude of nearly 7 km (22,960 ft). The third prototype (A-2) received a new 1,750 hp Jumo 213E engine. It too was provided with an annular radiator. With it, a maximum speed of 660 km/h (410 mph) was achieved at an altitude of 6 km (19/680 ft)

The canopy was placed in the center of the fuselage. It was a fully enclosed compartment that was riveted to the fuselage.

The Me 109 boasted an unconventional landing gear arrangement, at least for German standards, with the landing gear primarily affixed to the lower center base of the fuselage. This configuration centralized the aircraft’s weight at this pivotal point, while the two landing gear struts extended outward toward the wings. In contrast, the Me 209 utilized a wide-track undercarriage unit, with the pivot points being out on the wings.

Various sources have proposed different armament configurations for the Me 209. One suggestion was the installation of two 3 cm MK 108 cannons, each equipped with 70 rounds of ammunition, alongside two 2 cm MG 151 cannons with 250 rounds per cannon, all to be housed within the aircraft’s wings. Alternatively, another proposal suggested the placement of four MK 108 cannons within the wings and two MG 151 cannons positioned above the engine compartment. However, it remains unclear whether any of these proposed armament configurations were ever implemented on the Me 209A.

The side view of the only photograph of the Me 209A first prototype. Source: http://www.luftwaffephotos.com/lme2091.htm

Fate

In 1944, further testing ensued, yet for Messerschmitt, the advent of the new Fw 190D posed a challenge. The Fw 109D, slowly making its way into production, boasted better performance, being faster in both high and low altitudes. What ultimately sealed the fate of the Me 209A project was the swiftness and cost-effectiveness with which the Fw 190D could be put into production. While the Me 209 incorporated many components from the Me 109, setting up its production would demand considerable time. A luxury in short supply for the Germans in 1944. Additionally, Messerschmitt’s focus at that time was squarely on the new Me 262 production, leaving scant resources to spare for yet another piston-powered fighter.

Despite these challenges, Messerschmitt made a final push to advance the Me 209 project with the construction and testing of the fourth prototype, designated Me 209H V-1, in June 1944. This iteration underwent several modifications, including enlarged wings and propulsion by a DB 603G engine. Unfortunately, the first prototype fell victim to an air raid on August 14, 1944, casting uncertainty over the fate of the remaining aircraft. Although there were intentions to export the Me 209A to Japan, these plans never materialized. It was also competing with the Ta 152H, which was easier to put into production while also having better performance, at least on paper.

Prototypes

  • Me 209A-0- First prototype powered by a  1,750 hp DB 603A-1 engine
  • Me 209A-1- Secon aircraft is essentially a copy of the first prototype 
  • Me 209A-2- Third tested with a new 1,750 Jumo 213E engine
  • Me 209H V-1 – The fourth prototype powered by a DB 603G engine  and received  larger wings

Conclusion 

The Me 209A project ultimately reached a dead end, not because it was a poorly designed aircraft, but simply because it didn’t offer significant enough improvements to justify production. The new Fw 109D, boasting similar flight performance, was already in the production phase. Introducing yet another new design without any notable advancements in this fighter category would have been illogical and a waste of already meager resources.

Me 209A-2 Specifications
Wingspans 10.95 m / 35  ft 11  in
Length 9.62 m / 31  ft 6 in
Height 3.65 m /  12 ft  2 in
Wing Area 17.15 m² /  184.53 ft²
Engine 1,750 hp Jumo 213E
Empty Weight 3,475kg / 7,662 lbs
Maximum Takeoff Weight 4,200 kg / 9,261 lbs
Maximum Speed 660 km/h / 410 mph
Cruising speed 490 km/h / 305 mph
Range 690 km / 430 miles
Maximum Service Ceiling 13,000 m  / 42,650 ft
Crew 1 pilot
Armament
  • None

Illustration

Credits

  • Written by Marko P.
  • Edited by Henry H.
  • Illustrations by Oussama Mohamed “Godzilla”

Source:

  • D. Nesić  (2008)  Naoružanje Drugog Svetsko Rata-Nemačka. Beograd.
  • D. Monday (2006) The Hamlyn Concise Guide To Axis Aircraft OF World War II, Bounty Books.
  • J. R. Smith and A. L. Kay (1972) German Aircraft of the WW2, Putnam
  • D. Myhra (2000) Messerschmitt Me 209V1, Schiffer Military History
  • B. C.Wheeler, German Fighters of WWII, Aeroplane Special
  • R. Jackson (2005) Infamous Aircraft, Pen and Sword
  • M. Griehl () X-planes German Luftwaffe prototypes 1930-1940, Frontline Book

 

Stipa-Caproni

Italy, , , , ,

italian flag Italy (1932)
Experimental Aircraft – One Prototype Built

In the history of aviation, there have been many projects that on paper promised outstanding flight capabilities, or offered other technical advantages. The time before the Second World War saw aviation advance at a breakneck pace, and is well known for such experiments. The so-called Stipa-Caproni was one such project, being an intriguing, and somewhat bizarre, experimental aircraft designed by Italian aeronautical engineer Luigi Stipa, and built by Caproni during the interwar period. It was characterized by its tubular fuselage, hence earning it the nickname Flying Barrel.

The unique design Stripa-Caproni experimental aircraft. Source: Wiki

History

In 1927 a young Italian aircraft engineer Luigi Stipa began working on an unusual tube-shaped aircraft. Like many other aviation enthusiasts, Stipa was very interested in how aircraft could achieve better performance through exploring unorthodox construction methods. Thanks to his studies in thermodynamics, he was aware of the so-called Venturi effect, named after Italian physicist Giovanni Battista Venturi. In essence, this effect describes the reduction of fluid pressure and increasing velocity when it’s moving through a cylinder of decreased diameter. In theory, using this principle, a special type of aircraft could be created that could achieve significantly higher speeds than the conventional models of the time. Stipa theorized that for this purpose, such an aircraft would have to have a tube-shaped fuselage with the engine being positioned near the front. After finding it theoretically possible, he moved forward to test if the Venturi effect could be implemented in his airplane concept. For this purpose, he began a series of different tests inside a wing tunnel, carried out at the Aerodynamic Laboratory in Rome, from 1928 to 1931. The main focus of this testing period was to find the adequate shape, and leading edges, of the tube-shaped fuselage. This also included finding the right position of the engine, its position inside that tube, and the ideal propeller rotation speed. Following a series of wind tunnel tests, Stipa concluded that it was possible to build a full-scale prototype by using a single tube-shaped fuselage.

Luigi Stipa in his younger years. Source: Wiki

At the end of his research, he concluded that such a project was viable and set the task of building a working prototype. To gain interest in his project, he wrote about his work in the Rivista Aeronautica journal in 1931, and even built a small working replica. The next logical step was to write to the Italian Minister of Aviation, in the hope of getting approval for the realization of his project. Luckily for Stipa, his work came to the attention of General Luigi Crocco, the Air Ministry’s director. Stipa’s work was well received and the project received a green light. To test the concept, a working prototype had to be constructed.  It is important to note, that both Stipa and the Italian Air Ministry were aware that this project was merely to test his theories, and would not entail any further development of the prototype. In addition, both were aware that Stipa’s proposed principle was only practical on larger aircraft types.

For this purpose, the prototype was to be powered by a small 120-hp engine. The reason behind this decision lay in the fact that this aircraft was primarily built for evaluation and academic purposes. The Italian Air Ministry was not quite willing to invest huge monetary resources in it, beyond those necessary for the construction of the working prototype.

To help build the test aircraft, the Caproni aircraft manufacturer from Milan Taliedo was chosen. It was designated as Stipa-Caproni (sometimes referred to as Caproni-Stipa) referring to its designer and constructor. The prototype was built quickly and was ready for testing in October 1932.

It is perhaps a little surprising that such an unusual design would receive the necessary support for its realization. However, the exploration of new and unorthodox ideas in aviation was very popular in pre-war Europe. During the 1930s, Italy led the way in this aspect, perhaps even more than other countries, testing many unorthodox designs. What’s more, the Italian Fascist regime even encouraged different and unusual projects like this one, although many of them did not produce any meaningful results.

The Stipa-Caproni prototype was used for testing during 1932 and 1933. Source: en.topwar.ru

Technical specification

The Stipa-Caproni was a two-seater, mixed-construction aircraft, designed to have the simplest and thus cheapest fuselage. Its fuselage consisted of a tube which internally consisted of two large wooden round-shaped rings at the nose, followed by a series of similar but smaller rings. All of them were then connected with horizontal ribs which in turn were covered in fabric. The outer wooden rings served as the foundation, on which the wing and the cockpit would be connected. The fuselage design was, in effect, a large tube shaped airfoil.

A close-up view of the Stipa-Caproni internal fuselage construction. The two larger wooden rings serve as a base to which wings and the cockpit would be attached. Source: www.thevintagenews.com

The wings were mounted centrally on each side of the fuselage. These had a simple wooden construction, and were covered in fabric. They were also connected to the fuselage through metal bracing wires, which as a consequence increased the aircraft’s drag.

To the rear, a fairly large tail assembly was placed. During the design work of this aircraft, Stipa intentionally placed the rear control surfaces as close to the slipstream as possible. He hoped that this arrangement would greatly improve the aircraft’s handling and maneuverability.

On top of the fuselage, an elevated two-seat cockpit was placed. These were top-open with a small windshield placed in front of each position. There were also a pair of small doors that opened on the left side to give access to the seats.

The 120-hp de Havilland Gypsy III engine was placed inside this fuselage. It was centrally positioned and suspended using several steel bars that held it strongly in place. This was necessary to do so, as a weaker mounting could potentially endanger the aircraft during flight. The engine propeller was the almost the same diameter as the tube-shaped fuselage.

Given its overall design, and the position of the propellers inside the fuselage, the landing wheels were small and quite close to the ground. It consisted of three fixed road wheels. Two larger on the front and one smaller on the rear. Initially, wheel fairings were used but at some point, and for unclear reasons, these were removed.

A front view of the unusual engine installation. The engine itself was held in place by several metal bars. Source: Wiki
It was provided with a small and fixed three-wheel landing gear. Source: en.topwar.ru

Testing and Final Fate

With this project approved, a prototype was constructed and air tested in October 1932 at the experimental field at Monte Celio near Rome. Despite its odd design, the prototype was able to take to the sky without any major problems. Furthermore, it made several successful flights around Taliedo and Guidnia. It was even presented to the Italian Air Force for future test flights. During this period the aircraft was jokingly nicknamed Flying Barrel or Aereo Botte (Eng. Wooden wine barrel aircraft) or Aereo Barile (Eng. Fuel-Barrel aircraft).

The weight of the aircraft during these flights was 800 kg (1,874 lb), while the calculated wing loading was 44,73 kg/m² (9,16 lb sq.ft.). The maximum speed achieved was 133 km/h (83 mph), and it needed 40 minutes to climb at a height of 3, 000 m. It needed an 800 m long airfield to be able to take to the sky.

The Stipa-Caproni during one of many test flights. Source: www.historynet.com

Despite Stipa’s hopes that the position and shape of the tail control surfaces would improve its mobility, several problems were noted by the test pilots. Firstly the elevator worked very well, which ironically proved to be a major problem. Even with a slight movement of the command control stick by the pilots, the aircraft could prove very sensitive to elevator inputs. On the other hand, the rudder controls were quite stiff,  as a consequence the pilot had to use considerable force in order to use it effectively.  Analyzing this problem showed that the rudder’s large surface area was to blame for its stiff control. But besides the two problems, the aircraft was reported to be easy to fly when being used in a gliding flight. These defects  were of a more or less technical nature, which were not necessarily irremediable through further development of the overall design.

The design of the rear tail assembly proved somewhat problematic. Specifically, the elevator control was overly sensitive while the rudder was quite the opposite. Source: en.topwar.ru

The final results of evaluation flights showed that the Stipa-Caproni does not have any particularly great advantages compared to other more standard aircraft designs.  In addition, Stipa-Caproni’s overall aircraft shape offered limited space within the fuselage for passengers or payload.

As Stipa predicted from the start, his principles would not offer any major advantage over a standard smaller-dimension aircraft. The real application of the Stipa-Caproni design was only feasible on larger aircraft. Stipa hoped that his further research would enable him to construct large aircraft powered by two to three tube-shaped engine mounts. Unfortunately for him, after a series of test flights during 1932 and 1933 the interest in his work died out. It was briefly used in various Italian aviation propaganda publications before being scrapped in 1939.

Despite being in general an unimpressive design, the French showed interest in it. Particularly the company ANF Lex Maureaux, which went so far as to acquire a license for the design in 1935. According to initial plans, a two-engine variant was to be built for testing and evaluation. The project did not go beyond basic work was later canceled.

Lastly, an interesting fact is that many people considered Stipa-Caproni to design some sort of proto-jet engine. Whether this was the case or not, Stipa felt his work was overlooked, and according to some sources, he remained bitter throughout his life until he died in the early 1990s.

Stipa hoped that with more resources he would be able to test his principle on a much larger scale, but ultimately nothing came of it. Source: L. Stipa, Stipa Monoplane with Venturi Fuselage

Replica

In 1996, aviation enthusiast Guido Zuccoli began working on a smaller replica of this aircraft.  However, the death of Zuccoli in a landing accident caused a delay in the replica’s final delivery. It was finally completed in 2001 when numerous small flights were achieved. The aircraft, powered by a 72 hp Simonini racing engine, managed to achieve a flight distance of 600 m (1,968 ft). After that, the aircraft replica was stored as an exhibit at the Zuccoli Collection at Toowoomba, in Australia.

A smaller-scale replica was built and flight-tested in 2001. Source: www.uasvison.com

Conclusion

The Stipa-Caproni represented an intended for the purpose of testing his new concepts in practice. While surely an interesting and unusual concept, Stipa-Caproni’s overall design was not that practical in reality, offering little improvement over a standard aircraft design of similar dimensions.

 

Stipa-Caproni  Specifications
Wingspans 14.3 m / 46 ft 10 in
Length 6.04 m / 19 ft 10  in
Height 3.2 m / 10  ft 7  in
Wing Area 19 m² / 204 ft²
Engine One 120 hp (89.5 kW) De Havilland Gipsy III
Empty Weight 595  kg / lbs
Maximum Take-off Weight 850 kg / 1,874 lbs
Maximum Speed 133 km/h / 83 mph
Landing Speed 68 km/h / 42 mph
Climbing speed to 3,000 m 40 min
Maximum Service Ceiling 3,700 m / ft
Crew 1 to 2 pilots
Armament
  • None

Illustration

 

Credits

  • Written by Marko P.
  • Edited by Henry H. & Ed J.
  • Illustration by Godzilla

Source:

 

 

 

ANT-1

Soviet, WW2, , ,

 USSR (1921)
Experimental Single-seat light aircraft – 1 Prototype Built

While the Russian Civil War was raging on, there were early attempts to rebuild its shattered aviation industry.  Aviation engineers and enthusiasts attempted, despite the chaos around them, to build small experimental aircraft to test their ideas and concepts. One such young individual was Andrei Nikolayevich Tupolev. His ANT-1 was a specialized design to test the concept of using metal alloys in aircraft construction.

The ANT-1 experimental aircraft. Source: www.globalsecurity.org/military

History

Tupolev began his career as an aircraft engineer in 1909, when he was admitted to the Moscow Higher Technical School. There he met Professor Nikolai Yagorovich who greatly influenced Tupolev’s interest in aviation. In the following years, he spent time developing and testing various glider designs. When the First World War broke out Tupolev managed to get a job at the Russian Dux Automotive factory in Moscow, which produced a variety of goods, including aircraft. There he gained valuable experience of aircraft manufacturing.

Andrei Nikolayevich Tupolev was one of the greatest Russian/Soviet aviation engineers and designers. Source: Wiki

In 1917, the October Revolution plunged the disintegrating Russian Empire into total chaos. The few aircraft manufacturing centers were either abandoned or destroyed. All work on the design and construction of new aircraft was essentially stopped. The Dux was one exception and continued to work at a limited capacity. It was renamed to Gosudarstvennyi aviatsionnyi zavod (Eng. State aircraft factory) or simply GAZ No.1. Given that he was one of few aviation engineers left, with most skilled either being killed or fled the country, Tupolev remained working for the GAZ No.1. He spent a few years working on various projects such as designs improving weapon mounts for older aircraft that were still in service.

In 1921, Tupolev was elected as the deputy of the Aviatsii i Gidrodinamiki AGO (Eng. Aviation and Hydrodynamics Department). This department was tasked with developing various aircraft designs but also including torpedo boats. In 1921 he and his team from AGO began working on a new aircraft design that was to test new concepts. Two new innovative features were that it should be a monoplane, and be built using mainly metal alloy. Its primary purpose was not to gain any production orders, but instead to serve as a test bed for new ideas and concepts. The aircraft was named ANT-1, where ANT stands for the initials of  Andrei Nikolayevich Tupovlev.  This designation should not be confused with a snowmobile developed by  Tupolev, which shared its name.

During this period, Soviet aviation officials and the German Junkers company spent years negotiating the possibility of producing a Duralumin alloy that could be used for aviation construction. Junkers proved the validity of this concept on the J.I saw service during the First World War. The German company wanted to avoid sanctions on arms and aviation development imposed by the Allies, while the Soviets wanted the technology for themselves, not wanting to depend on the Germans entirely. The Soviet Union in 1922, managed to produce their own copy of Duralumin known as Kol’schugaluminiyem alloy. The name was related to a small village Kol’chugino where this factory was located. Limited production of this alloy began in 1923.

Due to problems with the production of the new alloy, Tupolev was forced to postpone the development of his new aircraft until 1922. At that time the alloy was not yet available, so Tupovlev decided to go on with a mix-construction design, but mostly using wood. The benefit of using wood was that it was an easily available material, with almost unlimited supply in Russia. It was cheap and there were plenty of skilled woodworkers. However, there were also numerous flaws in using wooden materials. The greatest issue was a generally short service life in harsh climates as in Russia, in addition, standardization of spare parts is almost impossible to do.

Tupolev himself preferred the new metal technology believing that it would offer many benefits to the aircraft industry,  giving new aircraft a lighter and stronger overall construction. Tupolev eventually decided to go for a mixed-construction solution. His decision was based on a few factors, such as the general lack of this new material, and he wanted to be on the safe side as using metal in aircraft construction was still a new and not yet fully proven concept. In addition, he wanted to be sure about the Aluminum alloy material’s quality before proceeding to design a fully metal aircraft.

Once the choice for the construction material was solved the next step was to decide whether it was to be a single or two-seat configuration. The wing design was also greatly considered. After some time spent in calculations and small wind testing, the choice was made to proceed with a single engine and low-wing monoplane.

For the engine, three different types were proposed including 14hp and 18 hp Harley-Davidson and a 20 hp Blackburn Tomtit. Despite Tupovlev’s attempts, he failed to acquire any one of these three. It was not until early 1923 that he managed to get his hands on an old 35hp Anzani engine which was over 10 years old by that point. Despite its poor mechanical state, Tupovlev knowing that nothing else was available decided to try salvage it.

Testing and the Final Fate

The construction of this aircraft took over a year to complete. Given the general chaos at that time, this should not be surprising. It was finally completed in October 1923, and the first test flight was carried out on the 21st of October of the same year. Despite using the older engine, the flight proved successful. It was piloted by Yevgeni Pogosski.

The completed ANT-1 test aircraft. Source: www.globalsecurity.org

Following this, the ANT-1 was used mainly for various testing and evaluation. It would see service in this manner for the next two years. In 1925 the aging engine finally gave up, and this made the aircraft unflyable. Tupovlev tried to find a factory that could potentially refurbish it. He ultimately failed, as the engine was simply beyond repair by that point.

The aircraft was for some time stored at Factory No.156.  The fate of this aircraft is not clear in the sources, however, there are few theories about what happened to it. After Tupovlev’s imprisonment by Josef Stalin, his plans and documentation were confiscated. The aircraft was believed to be also confiscated and scrapped in the late 1930s. Another possibility is that it was moved to another storage facility where it was eventually lost during the Axis Invasion of the Soviet Union in 1941.

Specification

The ANT-1 was designed as a cantilever low-wing monoplane aircraft of mixed construction. The fuselage consisted of four spruce longerons. The lower two were connected to the wing spars and  were held in place with four bolts. The parts of the fuselage starting with the pilot cockpit to the engine were covered in the metal alloy. This alloy was also used to provide additional strength of some internal wooden components of the aircraft fuselage. The pilot Pilot cockpit was provided with a small windscreen. Inboard equipment was spartan consisting only of an rpm counter, oil pressure indicator, and ignition switch.

The cantilever wings were made of single pieces. At the end of the two tips  (on each side of the wings) large wooden spars were installed. Some parts of the wing were built using metal parts such as the wing ribs,  The rest of the wing was mainly covered in fabric. The tail unit was made of wood, its surfaces were covered with a metal-fabric cover.

The fixed landing gear consisted of two large wheels. These were connected to a metal frame which itself was connected to the aircraft fuselage. Small rubber bungees acted as primitive shock absorbers.

Given that nothing else was available, the ANT-1 was powered by an old, refurbished 35-hp strong Bristol Anzani engine.

A good view of the ANT-1 internal wing and fuselage construction. Source: www.globalsecurity.org
The cantilever wings received on each side one large wooden spar. Source: Wiki
The pilot cockpit received only a few basic instruments and a small windshield. Source:www.globalsecurity.org

Conclusion

The ANT-1 despite its simplicity, and being built a single, cobbled-together prototype, could be considered a great success for Tupolev. Through this experimental aircraft, Tupovlev gained valuable experience in designing an aircraft by using metal alloy. This success emboldened Tupovlev to go even further and design and build the Soviet first all-metal construction aircraft known as ANT-2. The ANT-1 was Tupovlev’s first stepping stone in a long and successful career as an aircraft designer in the following decades.

ANT-1 Specifications
Wingspans 7.2 m / 23ft 7 in
Length 5.4 m / 17 ft 8 in
Height 1.7 m / 5 ft 7 in
Wing Area 10 m²  / 108 ft²
Engine One 35 hp Bristol Anzani engine
Empty Weight 230 kg / 5,070 lb
Maximum Takeoff Weight 360 kg / 7,940 lb
Maximum Speed 125 km/h / 78 mp/h
Range 400 km / 250 miles
Maximum Service Ceiling 600 m /  1,970 ft
Maximum Theoretical Service Ceiling 4,000 m / 13,120 ft
Crew 1 pilot
Armament
  • None

 

Gallery

 

 

Credits

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

Sources:

  • Duško N. (2008)  Naoružanje Drugog Svetsko Rata-SSSR. Beograd.
  • Y. Gordon and V. Rigmant (2005) OKB Tupolev, Midland
  • P. Duffy and A. Kandalov (1996) Tupolev The Man and His Aircraft, SAE International
  • B. Gunston () Tupolev Aircraft Since 1922, Naval Institute press