Category Archives: WW2

World War 2 saw the airplane rise to even greater importance than in the first World War. Air superiority became a crucial component of battlefield operations and air forces were massively expanded during the conflict.The Allied and Axis sides of the war developed enormous war machines, capable of developing and rolling out unprecedented numbers of advanced new military equipment in rapid response to changing conditions on the battlefield, as well keeping up with the technological advances of adversaries.

High altitude bombing raids and night fighting were hallmarks of the War for Europe, whilst aircraft carrier battles pitched the American and Japanese fleets against one another. The technology of the day was pushed to it’s limit with the use of superchargers in aircraft engines, the introduction of radar, and the rapid development of the jet engine by the war’s end.

The period ended as the Nuclear Age and subsequent Cold War were ushered in by the tremendous and tragic blows to Japan’s wearied people.

Heinkel He 176

Nazi flag Germany (1937)
Rocket Powered Aircraft – 1 Prototype Built

For many years artists often imagined that the He 176 would have looked something like this. [luft46.com]
Prior to, and during the war, the German aviation industry developed a series of operational and prototype aircraft designs. Among the leading new technologies, rocket-powered aircraft were being developed. The concept was initially tested prior to the war on a smaller scale, including limited theoretical tests and prototyping. But further development would lead to the creation of the first rocket-powered aircraft known as the He 176. While it wasn’t accepted for service, it proved that such a concept was feasible and set the stage for the later Me 163 rocket-powered aircraft.

History of Rocket Engine Development in Germany

Following the end of the Great War, Germany was forbidden to have an Air Force. This also included the development of aircraft designs, though this did not stop the Germans from experimenting with new aviation technology. One such new technology was rocket propulsion. One of the first such flights using rocket propulsion occurred in June of 1928, when aviation enthusiast Fritz Stramer took to the sky his rocket-powered glider. Another pioneer in rocket-powered flight occurred at the end of September 1929. A pilot named Fritz von Opel managed to take to the sky in his rocket-powered glider, named Ente (Duck). Von Opel was assisted by another prominent aircraft designer Alexander Martin Lippisch. While technically speaking these were not real rocket-powered flights, given that these gliders did not take to the sky using purely the rocket engine but were towed to altitude. Nevertheless, these flights showed that flight using rocket engines was possible.

Von Opel experimental take-off using a rocket propulsion. [L. Warsitz The First Jet Pilot]
Over the following years, Lippisch became quite interested in rocket technology and would join the Deutsche Forschungsinstitut DFS, where he worked as an engineer. There, he developed a series of new glider designs, like the DFS 40. This work would eventually lead to the creation of the Me 163 rocket-powered aircraft. The Junkers Aircraft company also was interested in rocket development as they built and tested rocket take-off boosters. One such engine was ground tested in 1936.

Another stepping stone in rocketry research was the work of Wernher von Braun. In 1932 and 1934 von Braun managed to successfully launch two rockets using liquid-fuel rocket engines. In 1935 he managed to come into contact with Dr. Ernst Heinkel 1935. After von Braun presented his work, Dr. Ernst was highly impressed and promised to provide von Braun with any assistance in his work. For this, he appointed a young and energetic aircraft engineer named Walter Wenzelunzel to assist von Braun. In order to properly test the installation of rocket engines in aircraft designs, a special test center was established at Kummersdorf in 1936.

The He 112 prior to the start of testing with the von Broun rocket engine. [luft46.com]
Dr. Ernst supplied this research team with a few He 112 airframes. The first He 112 was used for ground testing. For this reason, its fuselage was retained while its wings and the original engine were removed. The rocket engine, which ran on a combination of liquid oxygen and alcohol, would be placed in the rear of the fuselage, with the engine nozzle being placed just beneath the tail unit. Von Braun’s team installed the oxygen tanks in front of the cockpit, with the alcohol tank behind the pilot seat. The engine (the sources do not specify its precise designation) could provide a thrust of 1,000 kg (2,200 lb) with an endurance of 30 seconds. During the testing the engine exploded, destroying the aircraft in the process.

Despite this setback, the project went on. By this time, German Army Officials were becoming interested in the project. In order to maintain its secrecy, von Braun and his team were instructed to find a remote auxiliary airfield where these tests could continue to be conducted away from prying eyes. The team, wanting to be close to Berlin, chose a small field at Neuhardenberg, which was covered on most sides by dense forest. Temporary housing, cabins, and tents were quickly set up in 1937 and the work could finally go on.

In 1937 von Braun began close cooperation with another enthusiast of rocket engine development, Helmuth Walter. This cooperation was partly initiated by the German Air Ministry (Reichsluftfahrtministerium RLM) who intended to use the rocket engines for other proposals, like assistance during take-offs. Walter was a young scientist who was highly interested in rocket propulsion. He managed to obtain military funding, which greatly helped in his work. In 1936 he used a Heinkel He 72 to test this engine. In 1937, he even managed to get the attention of the RLM. The RLM formed a Special Propulsion System department (Sondertriebwerke) with the aim of experimenting with rocket engines in the aircraft industry. While this department was mainly focused on developing rocket engines for short take-off assistance, Walter wanted more than that. He intended to develop a strong rocket engine that could replace the standard piston engines of the day. Walter managed to develop such an engine, named Walter TP-1, which was fueled by the so-called ‘T-Stoff’ (hydrogen peroxide) and ‘Z-Stoff’ (water solution of either calcium or sodium permanganate).

Von Braun requested another aircraft which Henkel provided, this was the He 112 V8 (during these trials it received a slightly changed designation V8/U). The test pilot Erich Warsitz managed to take it to the sky using the aircraft’s original piston engine. Warsitz was a crucial pilot for the German early rocket and jet engine development, being heavily involved in testing and helping with the overall design of both the He 176 and He 178. At about 450 meters Warsitz activated the rocket engine, and during the 30 seconds of the engine burn phase, a speed of nearly 400 km/h (or 460 km/h (286 mph) depending on the source) was reached. Due to the dangerous leakage of the engine, the flight had to be aborted, but otherwise, the flight has deemed a success. This He 112 V8 would be returned to Heinkel, but two more aircraft (H7/U and A-03) would be donated to the rocket research program.

Test pilot Erich Warsitz whose experience and work proved to be vital for both He 176 and 178 aircraft development. [firstjetpilot.com]
After this flight, all further tests were conducted using the Walter TP-1 rocket engine. In contrast to the von Braun engine which used alcohol and liquid oxygen as fuel, Walter’s own engine used hydrogen-peroxide and calcium permanganate as a catalyst. This engine was deemed safer too, which is somewhat ironic given the corrosive and volatile fuel. To avoid accidentally coming into contact with the Walter engine fuel, the pilot had to wear a highly protective suit. If exposed to the corrosive fuel, it caused disintegration without actually burning.

More tests were conducted at this location until the end of 1937, when the research was to be moved to Peenemunde. Due to some delays, the tests on the He 112 continued on from April 1938.

Heinkel’s First Rocket-Powered Aircraft

Following the series of tests on the He 112, some officials from the RLM began showing great interest in the prospect of using a rocket-powered aircraft interceptor. It was originally hoped that this aircraft would be capable of vertical, or nearly vertical take-off. When sufficient altitude was reached, the aircraft was then to make a swift dive on its target, firing a volley of its full weapon load. After this attack run, it was simply to glide away once it was out of fuel, to its base of operation.

The work on the project was conducted under a veil of secrecy and began in 1936 at the Heinkel Rostock-Marienehe work. The following year the first drawings of the He 176 V1 (derived from “Versuchsmuster 1” meaning “Experimental Model”) were completed by Hans Regner. Interestingly the designers set a huge task in front of them, by actually trying to reach a blistering speed of 1000 km/h (620 mp/h). An astonishing and difficult feat to achieve with such a novelty design. This set a number of challenges that had to be overcome. One of them was a proper wing design able to withstand the pressure of such high speed. For this reason, it had to be designed to be flat, at only 90 millimeters thick, with very sharp leading edges. This in turn caused further problems, as this design would cause the aircraft to stall at low speeds. In addition, the installation of wing fuel tanks would be difficult.

In order to make the whole design smaller and thus save weight, the pilot had to be placed in a rather unpleasant semi-recumbent position, with his legs stretched out in front and the pilot’s seat reclined. This was also done to help the pilot better cope with the extreme G-forces that he would be subjected to during the extremely high forward acceleration. The fuselage had a very small diameter of only 0.8 meters (2ft 7in) and was specially designed according to the height of the test pilot, Warsitz.

The construction of the first prototype was undertaken at the Heinkel’s aircraft works in Marienehe. Once the aircraft was completed, it was to be transported to Peenemunde. The aircraft’s testing was conducted under great secrecy and was transported there via military escort in June 1938. Just prior to the actual testing, Warsitz was informed by RLM officials that given the experimental nature of the design, and Warsitz’s valued status as an experienced test pilot, he was advised not to fly it. Warsitz, who was heavily involved in the He 176 design, protested to Air Minister (Reichsluftfahrtministerium) Ernst Udet, who gave him permission to undertake the first flight. After this was settled, there were some delays with the assembly and engine adjustment.

The initial tests were undertaken on the ground. Due to unsuitable terrain and lack of a proper towing vehicle, ground testing proved ineffective. So it was decided to use the aircraft’s own engine for these tests, which were conducted at the end of 1938. Using the He 178’s own engine on the ground presented a new problem, namely the rudder could not provide steering during take-off. As the aircraft had no propellers to generate airflow, steering the aircraft using the rudder on take-off was ineffective, thus the only way to maintain the aircraft’s heading was by using the left and right brakes on the main wheels. This was quite dangerous for the pilot and the aircraft, as an imbalanced braking force could potentially lead to an accident. The result of the initial testing showed that some changes to the overall structural design were needed. For this, the Heinkel crews spent the winter of 1939 modifying the He 178.

First Flights

During the Spring of 1939, a series of small test flights were conducted with the He 178. Somewhat unexpectedly, the Heinkel team was visited by an RLM delegation led by Udet himself. After observing the He 178 on the short flight they were quite impressed, but surprisingly for the Heinkel team, Udet forbade any more flights on it. Mostly due to fear for the pilot’s life. After some delays, Warsitz visited Udet in Berlin and filed a plea that the project should go on. Udet finally accepted this and gave a green light.

A military delegation led by Udet observed the He 176’s initial short flight attempts. The man in the white suit is the test pilot Warsitz who is speaking with delegation members about the flight, with Dr. Ernst just behind him. [luft46.com]
While the first official flight of the He 176 was to be conducted under the supervision of many RLM officials, feeling that something might go wrong, Erich Warsitz and Heinkel’s team (without the knowledge of Dr. Erns) decided to perform the flight in secrecy. The date for this was set on the 20th of June, 1939. After a rough take-off, the pilot managed to take the He 176 to the sky. Given the small fuel load, the flight lasted around a minute. Overall, the first test flight was deemed a success. The following day, Udet and his delegation visited the site and observed another test flight.

The Fuhrer Inspects the He 176

Hitler during his inspection of the He 176.[L. Warsitz The First Jet Pilot]
A couple of days later Warsitz and Heinkel’s team were informed that any further flights were forbidden. The reason was that Hitler himself became interested in the project and wanted to personally see the aircraft. The He 176 was to be transported to the Rechlin Secret Test Center and shown to many high-ranking members of the Luftwaffe. On the 3rd of July 1939, the aircraft was to be demonstrated to a large delegation including Hitler himself. First, a flight of a He 111 equipped with rocket-assisted take-off was shown to Hitler, which greatly impressed him. Another Heinkel innovative design, the He 178 jet-engine powered aircraft, was also present. While it was not yet capable of taking to the sky it was used for ground testing. Next in the line for inspection was the He 176, after a brief examination of its interior by the delegation, the stage was set for it to take to the sky. The flight initially went well, but the pilot miscalculated and shut down the engine too soon. While still at high speed, he began descending rather rapidly. After several attempts to restart the engine, he finally succeeded, just before hitting the ground. The plane took an almost vertical climb of some 50 meters before the pilot regained control and landed it safely. Hitler and his delegation were under the impression that the pilot performed this maneuver intentionally to demonstrate the aircraft’s potential. For his flight, the pilot was awarded 20,000 Reichsmarks.

The End of the Project

After this exhibit, Heinkel’s team tried to prepare the He 176 for reaching speeds up to 1,000 km/h. Structural analysis of the design, on the other hand, showed that this would not be possible. For this reason, preparation for the construction of a second prototype was underway. It was to be powered by a von Braun rocket engine, which suggested that the aircraft could be launched vertically. This was possible thanks to weight reduction efforts sufficient to enable vertical take-off.

Ultimately the whole project would be canceled. The order was given by Adolf Hilter, who insisted that designs that could not enter production in less than a year, be canceled. Despite Heinkel’s attempt to win over Udet’s support, it went nowhere and the project was officially terminated.

The He 176 V1 was disassembled and transported to the Aviation Museum in Berlin to be exhibited. Sadly it would be later on destroyed in one of many Allied bombing raids. The He 176 V2 was almost complete, but its parts were eventually scrapped. The V3 had also been under construction, but was ultimately abandoned in its early stages.

Technical Characteristics

The He 176 was designed as an all-metal, high-wing rocket-powered experimental reconnaissance aircraft. Its fuselage had a simple circular cross-section design. The wings had an asymmetrical profile and were quite thin. During take-off, there was a significant chance of the wingtips contacting the ground, due to the fuselage’s small diameter and extreme vibrations during take-off. To avoid damaging them, Heinkel engineers added a “U” shaped metal bar under each wingtip as a temporary solution. The wings were also initially to act as fuel tanks, but this feature had to be abandoned on the prototype, and fuel was instead stored behind the cockpit. The tail and rudder design was more or less conventional.

To avoid causing damage to the wings during take-off, Heinkel engineers added a “U” shaped metal bar under each wingtip.

The rocket engine chosen for the He 176 was the Walter RI type. It provided thrust ranging between 45 kg to 500 kg (100 to 1,1100 lb) with an endurance of one minute. Due to the weight issues combined with a relatively weak propulsion unit, the desired speed of 1,000 km/h (620 mph) was never reached. The maximum speed reached by this aircraft differs greatly between sources. For example, D. Nešić mentioned that the maximum speed was only 345 kmh, while authors J. R. Smith and A. L. Kay quoted a figure of 700 kmh. Lastly, the test pilot himself in his own logbook mentioned that he managed to reach a speed of 800 kmh (500 mph).

The landing gear consisted of one front smaller wheel, two larger wheels 700 mm in diameter, and one more to the rear. While the front wheel was fixed the remaining three were completely retractable.

The He 176 during take-off [L. Warsitz The First Jet Pilot]
The cockpit provided the pilot with an excellent forward view and was made of plexiglass. Given the experimental nature of this aircraft, great attention was given to pilot safety. As in case of emergency, bailing out of the fast-moving and cramped aircraft was almost impossible. Heinkel engineers designed the entire cockpit section to be jettisonable. The cockpit assembly was connected to the fuselage by four locks which were equipped with small explosive charges. When the pilot was jettisoned from the fuselage his parachute would open automatically and allow him to land safely. This system was tested by using a wooden cockpit containing a dummy pilot. This trial cockpit was then taken to the sky by a He 111 and at sufficient height, it was released. The parachute opened without an issue and it landed on the ground intact. The results of the dummy pilot showed that this system was safe if the cockpit landed on soft ground.

The small size of the cockpit prevented the use of a standard instrument panel, as it would severely affect the pilot’s forward visibility. Instead, the instruments were placed to the left and the right of the pilot. Interestingly, while Heinkel did not intend to arm the aircraft, RLM officials insisted that two machine gun ports be placed beside the pilot. Due to the cramped cockpit interior, the two machine guns had to be placed where the pilots’ side controls were positioned. As this would cause delays and much-needed redesign work, the Heinkel engineers simply placed machine gun ports (without the actual machine guns equipped) and kept the original control units in place. The RLM officials, when visiting the work, were told that these were just temporary measures.

The Only Photograph

The real He 176 was quite different in design. [luft46.com]
Given the secretive nature of the project, RLM officials effectively gathered all films and photos for themselves. All persons involved in the project were also forbidden from taking any pictures. At the war’s end, the Soviets either destroyed or captured these and their final fate is unknown. Sometime after the war, many artists attempted to produce sketches of how the He 176 may have looked. These greatly differed from the original design, but given the lack of information and general obscurity of the He 176, this is understandable.

Conclusion

The He 176 project arose as a collaboration of several different parties. It was heavily influenced by rocket engine testing and development done by von Braun and Walter. Heinkel Flugzeugwerke provided the necessary resources and production capabilities, while test pilot Erich Warsitz provided valuable feedback which guided necessary changes and improvements to the design.

It was a novel idea to use rockets to power aircraft, which offered numerous advantages, such as reaching high speed and altitude very quickly. Given that this project was more or less a Heinkel private venture in the development of new technologies it likewise did not find a place in German military service. It, however, did set the stage for future designs like the Me 163, which actually saw some combat during the war.

He 176 Specifications

Wingspans 4 m / 13 ft 1 in
Length 5 m / 16 ft 4 in
Height 1.4 m / 4 ft 7 in
Wing Area 8 m² / 53 ft²
Engine Walter RI rocket engine
Empty Weight 1,570 kg / 3,455lbs
Maximum Takeoff Weight 2,000 kg / 4,400 lbs
Maximum Speed 700 km/h / 435 mph
Endurance flight Range 60 seconds
Crew One Pilot
Armament
  • None

Gallery

Illustration by Godzilla

Credits

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

Sources

  • D. Nešić (2008), Naoružanje Drugog Svetskog Rata Nemačka Beograd
  • M. Griehl (2012) X-Planes German Luftwaffe Prototypes 1930-1945, Frontline Book
  • D. Mondey (2006). The Hamlyn Concise Guide To Axis Aircraft OF World War II, Bounty Books.
  • D. Donald (1998) German Aircraft Of World War II, Blitz Publisher
  • J. R Smith and A. L. Kay (1972) German Aircraft of the Second World War, Putnam
  • Jean-Denis G.G. Lepage (2009), Aircraft Of The Luftwaffe 1935-1945, McFarland & Company Inc
  • L. Warsitz (2008) The First Jet Pilot The Story of German Test Pilot Erich Warsitz Pen and Sword Aviation

Sack AS 6

Nazi flag Germany (1943)
Experimental Circular Wing Aircraft – 1 Prototype Built

The unusual Sack AS-6 circular-wing aircraft [falkeeins.blogspot.com]
In the history of aviation there were many designers who had ambitious ideas and concepts for new designs, but never had the chance to bring their ideas to fruition. On the other hand, there were those who had radical or even completely impractical designs that did manage, at least to some extent, to be built. Germany had a fair share of such individuals, especially during the later stages of the Second World War. These designers may have proposed their projects out of desperation to save their country or in fear of being sent to the front. There were also those that were simply enthusiasts in aircraft development but lacked a better understanding of how aerodynamics actually work. One such person was Arthur Sack (1900-1964), who prior to the war came up with the idea of building a circular-wing aircraft known simply as the Sack AS-6.

History

Prior to the war, Germans were prohibited from developing and building military aircraft. The Germans simply bypassed this prohibition by instead focusing on gliders, but also on civilian aircraft which if needed would be quickly converted for military use and conducted secret experiments. They especially took great care in the development and investment of manned gliders, but also scale model-building competitions and organizations. While this may seem like a waste of time and money, it actually helped gain initial and valuable experience in aircraft development which proved vital for the later Luftwaffe.

One such model competition was the National Contest of Aero Models with combustion engines, held in late June 1939 at Leipzig-Mockau. Here, aviation enthusiast Arthur Sack presented his model of an unusually circular-wing-shaped aircraft named AS-1. It is sadly unclear why Sack pursued the design of such an unusual aircraft design. Due to engine problems, the AS-1 was unable to take off from the ground, so the small model had to be launched by hand instead. The Air Minister (Reichsluftfahrtministerium RLM) Ernst Udet, who was present at the event, seemed to be impressed with this design and advised Sack to continue its development.

Arthur Sack and his AS-1 model. [lvz.de]
Thanks to financial support from the RLM, Sack was able to proceed with the development and even the construction of a few scale models, a process that lasted some three years. In 1943 he submitted a fully operational model SA-5 to the RLM. The presentation went well for Sack and the RLM commission provided the necessary funds for the construction of a fully operational prototype. Interestingly, at some point Sack came into contact with another unusual aircraft designer Dr. Alexander Lippisch. While not completely clear, it appears that Sack received some design tips from Lippisch, to better improved his work.

With the order secured, Sack initiated the construction of a prototype. He named this aircraft the AS-6 V1 (Versuchs – version). As he had no proper workshop to build the aircraft himself, the glider manufacturer Mitteldeutsche Metallwerke was tasked with this instead. The initial work for the assembly of the aircraft began in the autumn of 1943. It took nearly half a year to complete the working prototype. Interestingly, due to the general shortage of materials, the AS-6 was constructed by utilizing a considerable amount of salvaged components from other damaged aircraft. For example, the cockpit canopy and parts of the interior were taken from a Bf 109B. Once the prototype was ready, it was allocated to the Luftwaffe for initial tests in early 1944.

AS-6 side view. [lvz.de]

Technical Characteristics

A good view of the AS-6 internal wooden frame construction.[all-aero.com]
The AS-6 was designed as an experimental prototype to test the idea of using circular-wing design. Sadly, this aircraft is quite obscure and poorly documented so not much is known about its overall design. It was a single-seater aircraft that was mostly built out of wood. It did not have a classical fuselage, instead, the majority of the aircraft consisted of two large circular wings. The internal design is more or less conventional with a wooden construction frame being covered with canvas. Two large elevators were installed on the rear of the wings. The tail assembly is a conventional design as well, consisting of one vertical stabilizer and two horizontal stabilizers.

The AS-6 rearview. The two elevators were too small, poorly designed, and did not provide adequate control during initially limited test flights. [all-aero.com]
The AS-6 was powered by an Argus As 10C-3 engine, which ultimately proved to be inadequate [all-aero.com]
The AS-6 was powered by a 240 hp Argus As 10C-3 engine driving a two-blade wooden propeller. The engine was housed in a metal frame, which was then bolted to the AS-6 fuselage. The engine was salvaged from a Bf 108 aircraft.

The cockpit canopy and its interior, as already mentioned, were taken from a Bf 109B. The cockpit was slightly elevated above the fuselage and provided the pilot with an excellent all-around view. The landing gear was also salvaged from a Bf 109B, but in the case of the AS-6, it was fixed. Initially, a landing skid was used on the rear, which was later replaced with a landing wheel instead.

The canopy and landing gear was taken from a damaged Bf 109 aircraft [ufxufo.org]

Testing the Prototype

Initial evaluation tests of the AS-6 prototype were conducted at the Luftwaffe Brandis Airbase. The flight tests were conducted by Rolf Baltabol Junkers test pilot. While several short take-offs were made, there were no attempts to actually take the aircraft to the sky. The test pilot noted that the aircraft had an overall poor design and was difficult to control. He urged that the control surfaces and rudder be completely redesigned. The engine was also deemed too weak. During the last short take-off, one of the two landing gear assemblies was damaged.

The AS-6, following its unsuccessful start, spent several weeks in repairs and received a number of modifications in an attempt to improve its performance. These included adding an additional 70 kg of weight to the rear, installation of brakes taken from a Ju 88, and repositioning the landing wheels to the rear by about 20 cm. Sack proposed moving the landing wheels further back, but the test pilot Rolf simply refused to fly it if this change was implemented. He argued that placing the landing gear to the rear would imbalance the aircraft potentially leading to tipping forward during a take-off. For this reason, the modification was not implemented. While the engine was underpowered, there were simply no alternatives available at that time.

The AS-6 during testing [falkeeins.blogspot.com]
The next test was scheduled for April 1944. During these tests, Rolf tried to take it to the sky, but failed again to do so. This time it was noted that the wings were simply too short. Further tests were canceled, the AS-6 was to await more modifications, and was to be tested in a wind tunnel; if possible with a completely new engine.

The fate of the AS-6

Following the unsuccessful testing, the AS-6 was stored at the Brandis airfield. In the summer of 1944, this airfield became the main operational base for the experimental Me 163 rocket-powered aircraft. The pilots of the I./JG 400 (charged with testing the Me 163) found the AS-6. One of its pilots, Franz Rossle, expressed a desire to attempt flying the unusual plane. But when the ground crew was preparing the aircraft for take-off, one of its landing gear units simply broke due to rough terrain, effectively preventing the test flight to be conducted. After this, it was once again stored at Brandis. It would remain there until early 1945 when it was lost in an Allied bombing raid.

The AS-7 project

While not clear when (possibly during early 1945), Sack approached Messerschmitt company with a proposal to use his circular-wing design on the Bf 109K-4 aircraft. The aircraft marked as SA-7 would be powered by a DB 605 2,000 hp engine. Fitted with circular wings it was theorized that it would be capable of carrying more armament inside the wings. It is believed (but not clear) that Messerschmitt was interested in this proposal and designated the project Me 600. Due to the war’s end, nothing really came from this project.

Conclusion

While certainly an unusual and interesting design, due to poor quality and salvaged materials used during its construction, the AS-6 performed poorly and never actually achieved flight. We will never know if the AS-6 circular-wing design offered any major advantage over more conventional wing designs. It appears that Arthur Sack did not continue with his idea after the war and passed away in the mid-1960’s. While his work was never implemented in mass production, his unusual design was often mistakenly taken as some advanced and secret German World War II project, which ironically, it never was.

AS-6 Specifications

Wingspan 16 ft 5 in / 5 m
Length 21 ft / 6.4 m
Wing Area 19.62 ft² / 211 m²
Engine One 240 hp Argus As 10C-3 engine
Maximum Take-off Weight 1,984 lbs / 900 kg
Crew 1 pilot
Armament
  • None

Gallery

Illustration by Ed Jackson

Credits

  • Written by Marko P.
  • Edited by Henry H. & Blaze
  • Illustrated by Ed Jackson

Sources

  • B. Rose and T. Butler (2006) Secret Projects Flying Saucer Aircraft, Midland Publishing
  • J. Dennis G.G. Lepage (2009) Aircraft of the Luftwaffe 1935-1945, McFarland and Company
  • Duško N. (2008) Naoružanje Drugog Svetsko Rata-Nemacka. Beograd.
  • http://www.luft46.com/misc/sackas6.html

Messerschmitt Me 163D Komet

Nazi flag Germany (1944)
Rocket-Powered Interceptor Prototype – 1 Built

The Me 163D prototype [luftwaffephotos.com]
The Me 163 showed to have great potential as a fast rocket-powered interceptor, but its design had some shortcomings. These included a limited view from the cockpit, lacking of landing gear, increased fuel storage, etc. The German companies Messerschmitt and later Junkers tried to resolve this by implementing a number of improvements to its design leading to the Me 163D of which only a few prototypes were built given the late start of the program.

History 

The Me 163 small size, while reducing the overall cost of the aircraft, enforced limitation of the fuel that could be stored inside which in turn led to a limited operational powered flight time of fewer than 8 minutes. In combat operations, this proved to be insufficient but no auxiliary tanks could be added to the Me 163 wings not inside of it. Another issue was the lack of proper landing gear. The Me 163 was instead forced to use a two-wheel dolly. Once the aircraft was in the air, the dolly was jettisoned. On occasion, there were accidents regarding this system when for example the dolly refused to be detached from the aircraft or even worse when it bounced off the ground and hit the aircraft from below. On the landing, the Me 163 were to use a simple retractable landing skid, placed beneath the fuselage. After landing the aircraft was immobile and essentially an easy target for enemy crafts.  For this reason, a normal retracting landing gear unit was desirable but once again due to Me 163 small size impossible to install.

To redress the previously mentioned issues engineers at Messerschmitt began working on an improved version named Me 163C. It incorporated a longer fuselage, extended cockpit, having an engine with two combustion chambers, and other modifications. The work on this version was rather slow and by war end not much was done on it besides a few incomplete airframes.

Illustration of a Me 163C aircraft, which was to replace the Me 163B. [walterwerke.co.uk]
One or two Me 163B prototypes had their fuselage extended in order if such modification was possible. [walterwerke.co.uk]
Parallel with the Me 163C development another project was carried out in early 1944 once again by Messerschmitt. This project was initially designated as Me 163D and was to have substantial numbers of improvements mostly regarding the overall shape of the aircraft, engine use, weaponry etc. For testing this new concept of substantially extending the aircraft fuselage if it was feasible at all. One or two (depending on the source) Me 163 (BV13 and BV18) was to be experimentally modified with an extended fuselage. In addition, experimental landing gear was also to be added. The testing of this rebuilt aircraft proved to be feasible and so the work on a fully built prototype began in earnest.

Name

The Me 163D project, due to Messerschmitt being simply overburdened with the Me 262 production, would instead be given to Junkers company. Once in their hands, the project was renamed Ju 248. The Me 163D obviously had an identity crisis as in late 1944 it was once again given back to Messerschmitt. Once back to its original designers, the project once again changed its name, this time to Me 263. As all three designations are basically correct for this aircraft, this article will use the original Me 163D designation for the sake of simplicity and to avoid any possible confusion.

First Prototype

Despite being originally designed by Messerschmitt, it was actually assembled in Junkers factories sometime during August 1944 or in early 1945 (the sources are not clear here). After that it would be returned to Messerschmitt where it was planned to examine and test its overall performance. While it was intended to have an increase in fuel capacity and an improved engine, the first prototype had actually no engine installed at that time. The Me 163D V1 (DV-PA) prototype was also provided with a new retractable tricycle landing gear which was to help with the mobility during the ground drive.

Given that no engine was fitted to the Me 163D, first flight testing was done as a glider, in late 1944. After these were conducted the prototype was in a series of wind-tunnel testings. The results of these two test trials (flight and wind tunnel) showed that the Me 163D was not capable of safely achieving dive speeds that were greater than its normal flight speed. In this regard, it was inferior to the original Me 163 aircraft which could achieve extensive dive speed but still managed to preserve good flight controls. The Messerschmitt engineers at this phase even considered redesigning the rear tail unit, but nothing came of it. The tricycle landing gear units did not offer good mobility on the ground, this was mainly due to it being too narrow. The Germans had plans to test using a parachute that was to be released during landing to help reduce the need for a long airfield. If this was tested or even installed on a Me 163D is unknown.

Technical characteristics

The Me 163D like its predecessor was designed as a high-speed, rocket-powered, swept-wing tailless aircraft. Given its experimental nature and its late development into the war, not much is known about its precise technical characteristics. Its overall construction would probably be similar to the previous versions, with a fuselage being built of metal and wooden wings.

The semi-monocoque construction fuselage was longer and was now 7.88 m ( 25 ft 10 in) compared to the original 5.84 m (9 ft 2 in) length. It had a good overall aerodynamic shape. The wings were swept to the back at a 19° angle, compared to the Me 163B 23.3° angle.

The Me 163D like its predecessor had wings that were swept to the back at a 19° angle. The fuselage had an excellent aerodynamic shape. [forum.warthunder.com]
The pilot cockpit received a new ‘bubble-shaped canopy. This provided the pilot with a much greater field of view. Given that it was intended to operate at great heights, the Me 163 D cockpit was to be pressurized and for this was bolted to the fuselage.

The Me 163D received a much better canopy which offered a much better all-around view. It was also completely pressurized so that the pilot could effectively fly it, on great heights. [forum.warthunder.com]
Interior of the Me 163D pilot cockpit. [forum.warthunder.com]
The Me 163D was to be powered by an improved Walter 109-509C rocket engine. It was provided by two combustion chambers.  While the sources are not clear if this engine was ever installed in the Me 163D, the estimated maximum speed was noted to be 950 km/h (590 mph) or up to 1,000 km/h (620 mph) depending on the source. It should also provide more economical consumption of fuel providing an operational range of some 160-220 km (100-140 mile) once again depending on the source. The operational flight endurance was increased from 7 minutes and 30 seconds to 15 minutes.

To overcome the previous Me 163B version’s lack of proper landing gear, the Me 163D was provided with the retractable tricycle landing gear. It consisted of a forward smaller and two larger wheels in the rear, just below the wing roots. All three of these retracted to the rear into the fuselage.

The fuel load consisted of 1040 liters (229 gallons) of T-Stoff and 492 liters of C-Stoff. The Me 163 was notorious for having only a limited endurance flight ofOnce the fuel was spent the pilots were to simply glide the aircraft back to the base.

The armament consisted of two 30 mm (1.18 in) MK 108 cannons, which were placed in the wing roots. Depending on the source the ammunition storage for each cannon ranged between 40 to 75 rounds.

Production

It is often mentioned in the sources that one complete and one partially complete prototype were built, by the war’s end. According to M. Griehl (Jet Planes of the Third Reich)  on the other hand, mentioned that at least three prototypes were built with less than 20 aircraft being in various states of construction when these were captured by the Allies in 1945.

Service

The limited operational test use of the Me 163D  and the German plans for it is not clear. Once again depending on the sources, there are mostly two versions. It appears that despite some faults in its design the Germans were willing to proceed with its further development. Given the end of the war, it should not be surprising that this was ever achieved. In another version, the work on the Me163D after some testing flight in February 1945 was officially terminated by the Luftwaffe officials. Mostly due to the fact that production of its unique and dangerous fuel is no longer possible.

The fate of these aircraft is not clear, given either information that these were either destroyed or captured by the Soviets. The latter option seems more likely as some sources suggest that the Soviets based on the Me 163D after the war developed their own version of it, the I-270. The project led nowhere and it would be abandoned.

    • Me 163D V1 – Completed prototype
    • Me 163D V2 –  Incomplete second prototype
    • Me 163D V3 –  Possible third prototype being built with additional 18 airframes

Conclusion

Given its experimental nature and its late introduction, it is quite difficult to make the final decision on the general properties of this aircraft. While it introduced some improvements in comparison to the previous version it also had issues regarding its reaching speed during dive flights. Despite offering the Germans a relatively cheap aircraft the whole Me 163 project by 1945 was essentially over given the general impossibility of production of its unique fuel. Nevertheless despite its downsides, the Me 163 whole series was certainly an interesting concept that had some merits that unfortunately for the Germans were never completely implemented.

Me 163D V1 Specifications

Wingspans 31 ft 2 in / 9.5 m
Length 25 ft 10 in / 7.88m
Height ft  in  /  3.17 m
Wing Area 192.6 ft² /  17.91 m²
Engine HWL 509  rocket engine
Empty Weight 4,400 lbs / 2,000 kg
Maximum Takeoff Weight 11,660 lbs / 5.300 kg
Maximum Speed 590 mph / 950 km/h
Operational range 100 mil / 160 km
Engine endurance 15 minutes
Maximum Service Ceiling 52,480 ft /  16,000 m
Crew One pilot
Armament
  • Two 30 mm MK108 cannons

Gallery

Artist Conception of the Me 163C – by Carpaticus

Artist Conception of the Me 263 – by Carpaticus

Credits

  • Written by Marko P.
  • Edited by Henry H. & Ed J.
  • Illustrated by Carpaticus

Source:

  • D. Nešić (2008)  Naoružanje Drugog Svetsko Rata-Nemcaka. Beograd.
  • E. T. Maloney and U. Feist (1968) Messerschmitt Me 163, Fallbrook
  • M. Emmerling and J. Dressel  (1992) Messerschmitt Me 163 “Komet” Vol.II, Schiffer Military History
  • J.R. Smith and A. L. Kay (1990) German AIrcraft of the Second World War, Putham
  • http://www.walterwerke.co.uk/walter/me163d.htm
  • W. Spate and R. P. Bateson (1971) Messerschmitt Me 163 Komet , Profile Publications
  • M. Ziegler (1990) Messerschmitt Me 163 Komet, Schiffer Publishing
  • D. SHarp (2015) Luftwaffe secret jets of the Third Reich, Mortons Media Group
  • M. Griehl (1998) Jet Planes of the Third Reich, Monogram Aviation Publication

Dewoitine D.520

French flag France (1936-1953)
Fighter – 900 Built

A restored D.520 in GC I/3 camouflage. [le blog du lignard]
The Dewoitine D.520 was the most advanced French fighter aircraft of the World War II period to have been employed in large numbers during the Battle of France. It was superior to the Morane-Saulnier MS.406 and Bloch MB.152. Often considered the only French fighter able to challenge the dominance of the Luftwaffe’s Bf 109E, the D.520 garnered a strong reputation and popularity among the general public in France. Though this aspect of its history is typically overlooked, the Dewoitine would also see extensive service after the Battle of France, particularly in the air force of the Vichy Regime, but also with Germany’s Italian and Bulgarian allies.

Dewoitine: French Pioneer of Interwar Metal Monoplanes

The Constructions Aéronautiques Emile Dewoitine (Emile Dewoitine Aeronautical Manufacturing) society was founded in 1920 under the lead of the eponymous engineer. Dewoitine had previously been employed by Latecoere during the First World War, which gave him experience on the subject of military aviation.

Dewoitine’s company was located in South-Western France, in Toulouse – an ideal location for strategic industry, as it was about as far as one could be in France from what was still viewed as a potential future adversary in 1920, namely Germany.

Dewoitine’s main products quickly became monoplane fighters. Though other types of planes were also developed, it was with parasol wing monoplanes that Dewoitine met its initial success. While the company failed to procure major domestic orders, Dewoitine fighters such as the D.1, D.9, or D.25 were export successes, seeing service in a number of countries such as Switzerland, Czechoslovakia, Turkey, Italy or Argentina. Dewoitine’s fighters were occasionally quite innovative – for example, the Dewoitine D.9 was an entirely metal parasol wing fighter, which was quite remarkable for a plane which first flew in 1924. While rejected by France, it was licence-produced by Italy as the Ansaldo AC.3, with 150 being manufactured for the Regia Aeronautica. Dewoitine also manufactured small numbers of D.9s for Belgium, Switzerland, Yugoslavia and Hungary.

Dewoitine’s D.9 metallic parasol monoplane fighter. [Aviafrance]
In large part due to none of its planes being adopted by France’s military, Dewoitine faced considerable woes in the late 1920s, being liquidated in January of 1927, before being re-founded the next year. The 1930s would prove more fruitful for Dewoitine. Most notably, the company won some sizeable contracts in the mid 1930s for its Dewoitine D.500, D.501 and D.510, which were low wing, or cantilever-wing, monoplanes, the latter two featuring, a 20 mm autocannon firing through the propeller hub. With more than 300 aircraft ordered for French service, and some limited export contacts, the Dewoitine cantilever wing monoplanes powered the company through the 1930s, and formed the bulk of France’s fighter force all the way up to 1938-1939.

A Dewoitine D.510 in flight. The D.500/501/510 fighters were a great achievement for, Dewoitine which helped cement the manufacturer’s credibility as a major French fighter manufacturer. [avion-légendaires]
Dewoitine first experimented with a cantilever-wing monoplane fighter with a retractable landing gear in the form of the D.513 fighter which first flew in January of 1936. It generally proved quite disappointing, suffering from instability, and was unable to reach the speed that was expected of it, while also suffering from cooling and landing gear problems, leading to the fighter quickly being discontinued.

The Birth of the “520”

In the French Air Force’s nomenclature, the role of single-seat fighters was classified “C1” (C for chasseur, the French equivalent of fighter, and 1 for single-seat). The air force department in charge of equipment procurement, the Service Technique Aéronautique (STAé – ENG : Aeronautical technical service), would regularly publish calls for aircraft manufacturers to design fighters to fill this role along with a series of required specifications. By late 1936, the last design request had been formulated more than two years prior, in March of 1934. The aircraft from this program, which was being considered for adoption, Morane-Saulnier’s MS.405 (which would become the MS.406), was still in the prototype phase, and had yet to receive orders for production.The MS.405 was already a fairly modern fighter, being a cantilever wing monoplane with a retractable landing gear. But Dewoitine believed that more advanced fighters using the same features could be developed. Anticipating a new design request for the C1 role, Dewoitine began development of a single-seat fighter in late 1936. It was not long before the STAé issued a new request. On the 12th of January 1937, aircraft manufacturers were asked to design a fighter able to reach a maximum speed of 520 km/h, climb to 8,000 meters in less than 15 minutes, land on a runway of 400 meters, and featuring a centerline Hispano-Suiza 20 mm HS.9 autocannon and two 7.5 mm MAC 34 machine-guns, equivalent to the armaments on the D.520 and MS. 405/406.

As the Dewoitine fighter project was still very early in development when the specifications were issued, its design took them into account. The requested maximum speed, 520 km/h, ended up being the project’s number designation.

Another major event happened in March of 1937, when Dewoitine’s Constructions aéronautiques Emile Dewoitine was nationalized by the French state. This was part of a massive nationalization plan that concerned all aspects of France’s defense industry, which was being run by the socialist-leaning popular front government in power since May 1936. Though this meant Dewoitine’s company was now state property, Emile Dewoitine was not displaced in his function as main engineer and leader of the company. The company, however, took a new name – Société Nationale des Constructions Aéronautiques du Midi (SNCAM – ENG: National Society of Aeronautical Constructions of the Midi -‘Midi being the area allotted to the company near Toulouse).

Though Dewoitine was still in full control of his company, all of the reorganization that took place in 1937 meant that work on the D.520 was mostly postponed or paused, resuming only in 1938. On the 3rd of April 1938, SNCAM obtained a contract for the construction of a prototype. Production of the first D.520 began and the prototype, D.520-01, would take off for the first time on the 2nd of October 1938.

Design of the Dewoitine fighter

The first D.520 prototype in flight. [joseph bibert fichiers]
The fighter aircraft designed by Dewoitine and his team was a low, cantilever-wing monoplane fighter that used an Hispano-Suiza 12Y in-line engine. The plane used riveted duralumin construction, both in structure and skinning.

The D.520’s wings used a one-piece, reinforced single-spar structure. Two MAC 34 7.5 mm machine-guns with gun cameras were installed towards the front, closer to the fuselage, while further inboard in the wings, a 120 liter fuel tank was located. To the rear were the flaps, which were also the only part of the aircraft covered with fabric instead of duralumin. Without the flaps, the wings had a surface of 13 square meters. The flaps had a surface area of 1 square meter, and each wing had a surface area of 14 square meters in total. When counting the wing root, where the fuselage and wings meet, the surface area was 16 square meters. On the first prototype, there was no radiator in the fuselage, and instead a radiator was installed under each wing.

The D.520-01 prototype used a Hispano-Suiza 12Y-31 V12 890 hp engine, without the cannon installed, though later prototypes, followed by production models would use more powerful versions of the Hispano-Suiza 12Y engine with provision for a 20 mm gun firing through the propeller hub. Between the engine and pilot, a 396 liter fuel tank was located (though typically it would only be filled for ferrying, and not combat operations). With a total fuel capacity of 636 litres, the D.520 had high endurance, with a ferrying range of up to 1,500 km in good weather.

The landing gear of the D.520 opened outwards. The definitive production model of the D.520 had a length of 8.6 meters, a wingspan of 10.2 meters, and a height of 3.435 meters.

Prototype Testing

The first prototype, D.520-01, was in some ways more of a demonstrator than a true prototype. From the start, the prototype had a number of differences from the standard models. The model of Hispano-Suiza 12Y that was used, the 12Y-21, did not have a provision for a propeller-hub-firing cannon, and with 890 hp, was less powerful than what was later installed. The wing machine-guns were not mounted either. During its first flight, the prototype failed to reach the desired speed of 520 km/h, not exceeding 480, and several issues were found. The two wing radiators caused too much drag, and a fuselage-mounted radiator was chosen instead. The tail’s control surfaces were found to be too small, and were enlarged. New exhaust pipes were also installed. The 12Y-21 engine was replaced by a 12Y-29, which produced 910 hp. Lastly, a variable pitch propeller was also installed.

A view of D.520-01 in flight. [Guerre et Histoire – Sciences et vie]
The first D.520 prototype undertook a second flight on the 11th of January 1939. This second attempt was much more successful, and showed great promise. It possessed good dive capabilities, with the prototype reaching more than 800 km/h in a dive, and reached 525 km/h in level flight, exceeding the 520 km/h required of the specifications.

A formidable view of the second D.520 prototype in flight over fields, France, 1939. [WW2aircrafts.net]
The second prototype of the D.520, D.520-02, had its first flight on the 28th of January, 1939. This prototype was much closer to the production model. It was fully armed, including the 20 mm propeller mounted autocannon, and had incorporated all the changes the D.520-01 had undertaken, as well as some new ones: a new landing gear and larger empennage. On the 5th of May, the third prototype, D.520-03, took to the air for the first time. This example featured the 12Y-31 engine, with full armament.

With successful trials of the second prototype, a production order for the D.520 was first placed on the 7th of April 1939, with 200 fighters ordered. The successful trials of the third prototype led to an additional order, initially for 600 aircraft, though reduced to 510 in June. In September, France entered into conflict with Germany, which saw widespread industrial mobilization and orders for new equipment. The total number of D.520s on order rose to 1,280 and through most of 1939, production was being set up at SNCAM’s facilities at Toulouse. Orders continued to accumulate, with 2,250 aircraft on order in April of 1940, including 120 for the navy.

In the meantime, testing continued on the D.520 prototypes. On the 11th of January 1940, D.520-02 was flown by pilot Leopold Galy in diving trials. During a dive from an altitude of 8,000 meters, the aircraft reached a speed of over 900 km/h – Leopard Galy indicated that the instruments showed the speed that the aircraft reached as 920 km/h.

Production Model: Features and Performance

Plans of the Dewoitine D.520 production model. [joseph bibert fichiers]
The first D.520s from the production run took to the air in November of 1939. A number of additional features had been added to Dewoitine’s fighter. The newer Hispano-Suiza 12Y-45 engine was chosen, as this model produced 935 hp and featured a much improved Szydlowski-Planiol supercharger, providing the Dewoitine with better high-altitude performance.

The armament of the production model consisted of a Hispano-Suiza HS.404 20 mm autocannon firing through the propeller hub (the prototypes used the earlier HS.9). The HS-404 had a rate of fire of 700 rpm, with a drum magazine holding only 60 rounds, the D.520 could expend its 20 mm ammunition in 9 seconds of continuous fire. The MAC 34 machine-guns were provided with more ammunition. Chambered for the 7.5×54 mm French cartridge adopted in 1929, the MAC 34 machine-guns had 675 rounds each. With a rate of fire of 1,200 rounds per minute, the MAC 34 would expend their ammunition in a little over half a minute. These machine-guns were electrically heated to avoid ice jamming the gun action at high altitudes.

The mounting of the MAC 34 machine-guns in the D.520’s wings. [L’Armement des avions de chasse français]
Empty, the D.520 had a weight of 2,050 kg. The aircraft had a structural weight of 892 kg, the engine block empty 517 kg, additional engine accessories 373 kg, empty fuel tanks 56.4 kg, and additional equipment 252 kg. 650 kg would be added on average to get the plane into operation: 337 kg of fuel (the aircraft’s fuel tanks had a capacity of 636 litres), 226 kg including the guns and their ammunition, and an average of 87 kg for the pilot and his equipment. The weight of the plane in operation would therefore be 2,740 kg. With a wing surface of 16 square meters, this meant the D.520 had a quite high wing load of 195 kg/cm2. The D.520 used a three-bladed Ratier variable pitch propeller, with a diameter of 3 meters.

The plane had an automatic fire extinguishing system controlled from the cockpit. As for fuel capacity, the plane featured a 396 liter self-sealing fuel tank located between the cockpit and the engine. Each wing featured a 120 liter fuel tank. The D.520’s fuel capacity of 636 liters was fairly considerable by 1940, and would give it a better range than most one-engined fighters used in Western Europe, with a ferry range of about 1,500 km.

The D.520 could reach a maximum speed of about 535 km/h at the altitude of peak engine performance, which was 6,750 m, and with the engine running at 2,400 rpm. Cruising speed at the same altitude was of 400 km/h with the engine running at 2,000 rpm. The stall speed was 125 km/h.

The rate of climb was 12 meters per second for the first 1,000 meters of flight. 4,000 meters could be reached in a little under 6 minutes, and thanks to its supercharger, the D.520 retained a good climb rate at high altitude. It reached 6,000 meters in 9 minutes and 8,000 meters in a little under 14 minutes. The D.520 would typically be capable of reaching those altitudes before the Bf 109E. The ceiling of the Dewoitine fighter was 11,000 meters.

Though the first examples of the D.520 were completed in November of 1939, some changes were still made, notably, the engine block was lengthened by 16 cm, meaning the first examples produced had to be retrofitted. The D.520 would only commence delivery to the air force in January of 1940, and by May, only a single fighter group had been equipped, though several would receive the new type as production was hastened during the Battle of France.

The aircraft were painted in the standard French air force camouflage scheme of brown, green, and gray color during their manufacturing process. The rudder section was painted in the colors of the French flag. The type of the aircraft (Dewoitine D.520) as well as the aircraft’s production number were indicated in black letters over this French flag-colored tail. French roundels were featured on the wings and on the central fuselage. The underside was typically painted in the same metallic gray color as parts of the fuselage and wings. The propeller hubs and propeller were painted in black.

Two completed D.520s outside of Dewoitine’s factory, 1940. [Archives Départementales de la Haute-Garonne, Airbus collection]
D.520s that have just been delivered to the air force, aligned before they are tested, 1940. [Archives Départementales de la Haute-Garonne, Airbus collections]
The D.520 assembly lines at Saint-Martin du Touch in February of 1940 [sam40.fr]

Future Production Models as Planned in 1940

Improved versions of the D.520 were quickly scheduled for production, and it was planned that these improved models would quickly be introduced to the production lines in the summer of 1940, if everything went well.

The D.521 was an experimental aircraft which mated the D.520 fuselage with the British Merlin III engine. Only one prototype was built, and it was not meant for serial production. The D.522, 523, 524 and 525, however, were D.520s powered by more powerful versions of the Hispano-Suiza 12Y engine.

The D.522 actually went back to the old Hispano-Suiza 12Y-31 860 hp engine block, which was significantly less powerful than the 12Y-45 on paper. It would, however, be fitted with a new Hispano-Suiza supercharger, larger in size than the Szydlowski-Planiol and providing better high-altitude performance. The planned production run for the D.522 was of 75 aircraft, from the 526th to the 600th Dewoitine fuselages, which would likely have meant the production run would have commenced in July of 1940. The D.522 would then have been succeeded by the D.523.

The D.523 used the 12Y-51 model of the 12Y engine, but retained the Szydlowski-Planiol supercharger. This new model of the 12Y produced up to 1,000 hp at optimal altitude. One D.523 prototype was produced (using the 45th D.520 fuselage), and underwent trials from the 9th to the 14th of May 1940. It was able to reach a maximum speed of 570 km/h at the optimal altitude, and climbed faster than the D.520 by a significant margin. This would have made this model a powerful rival to German Bf 109E and F fighters.

Though the D.525 was nominally the last, it was to be produced between the 523 and 524, and was more closely related to the 523 than the 524 was. The D.525 merely combined the 12Y-51 engine from the D.523 and the Hispano-Suiza supercharger from the D.522. Just 30 were to be produced, fuselages 751 to 780.

Finally, the D.524 was to be the last direct derivative of the D.520 scheduled for production by 1940. Its main improvement over previous models was to be the Hispano-Suiza 12Z engine – the most refined model of Hispano-Suiza’s 12Y engine yet, it was to produce 1,300 hp. While very promising in concept, the D.524 was yet to reach the prototype stage by the Invasion of France. While D.520 variants using the 12Z would come to be built at prototype stage later, the D.524 was canceled with the fall of France. It was expected to reach a maximum speed of around 616 km/h at 7,000 m, and climb to 8,000 m in 8’20’’.

By the armistice of June 1940, which put a temporary end to the D.520’s production run, about 440 aircraft had been manufactured, of which closer to 350 had been accepted by the French Air Force. This meant that no further D.520-derived models would see production, and plans to produce them were indefinitely shelved and never revisited.

A rear view of the HD 780 prototype, which featured a significantly redesigned wing as well as the necessary provisions to enable the land-based monoplane into a floatplane fighter. The HD 780 never flew and, as such, its performance data is not known. An estimate placed its maximum speed at around 440 km/h. [war thunder forums]
A floatplane fighter version of the D.520, the HD 780, had also been designed, with one prototype being produced. It incorporated many differences, such as folding, gull-shaped wings, a larger engine block, and two large floats. The prototype was completed in March of 1940, but remained inside its factory and would never take flight.

Into GC I/3

While the first serial-production D.520 had been delivered in November of 1939, these aircraft would later have to be revised and were by no means ready for service.

Dewoitine D.520 n°12 of GC I/3 in early 1940. The plane was flown by French pilot Commandant Thibaudet. [ww2fighters.e-monsite.com]
The D.520 would start effectively entering service during the first months of 1940, with the first squadron, GC I/3, being entirely outfitted with the type in the months of April and early May 1940. There, the D.520 replaced the Morane-Saulnier MS.406. Although another monoplane fighter with a retractable landing gear, the Morane was a plane which had noticeably lower performance in comparison to the Hawker Hurricane or Bloch MB.152, let alone the “triad” of modern fighters available by 1940, which would consist of the Spitfire Mk.I, the Bf 109E and the D.520.

As such, by the start of the campaign, the French Air Force had one squadron fully outfitted with the new fighter type. This fact, however, was tempered to a considerable extent. As mentioned previously, the fighters had only just been delivered to the squadron by the time fighting began in May of 1940. In other words, there had been little to no time for the pilots to accommodate with the newer fighter and become properly accustomed to it – which would prove a larger issue than anticipated, as the D.520 would prove a quite complicated and technical plane to pilot. Many of the pilots which flew the D.520 into combat during the Battle of France – perhaps even more so in the squadrons which would receive the plane during the campaign, would engage in combat during some of their first ten or even five flights of the D.520. Under these circumstances, one could hardly expect good performance with the pilots under such duress.

As hostilities began on the 12th of May, GC I/3 quickly moved into position at the airfield at Wez-Thuisy, in the Marne region of North-East France. From this point, the squadron would be engaged for the rest of the campaign all the way until the 17th of June, when it would retreat to the other side of the Mediterranean to avoid the capture of its planes.

The typical missions of the squadron were defensive, as simply put, the French Armée de l’Air struggled to impose any form of threat against the Luftwaffe. A large number of reasons for this can be attributed to this defensive role of the French air force. One could easily identify the comparative lack of modern fighters in comparison to a Luftwaffe that now universally operated the Bf 109E, a lack of coordination between the French air and ground forces, and many other limiting factors. As such, the D.520 would typically be used to try and intercept flights of German bombers, typically Heinkel He 111s or Dornier Do 17s, as these harassed French logistical centers and cities. In this role, the D.520 would enjoy some successes. It was faster at straight and level flight, and a better climber than previous French fighters, which was quite significant as the German bombers were moderately fast aircraft. The Morane Saulnier MS.406, notably, always struggled to catch the fast German bombers, while the D.520 could do so with relative ease.

Four pilots of the 2nd flight of GC I/3 in front of D.520 n°73 in 1940. [ww2fighters.e-monsite.com]
An MS.406 of GC III/6 before the squadron converted to the D.520. The older Morane monoplane was already fairly lacking by its introduction in the late 1930s, outperformed by the Hawker Hurricane or early variants of the Bf 109. Still fielded in large numbers during the campaign of France, the fairly sluggish monoplane would often struggle to intercept German fast bombers, particularly the Dornier Do 17 and Junkers Ju 88. [ww2fighters.e-monsite.com]
The D.520 was credited with its four first victories on the 13th of May, when planes from GC I/3 shot down an He 111 bomber from KG 55 as well as three Henschel Hs 126 reconnaissance planes. The next two days, 14th and 15th, would see very heavy engagements for the squadron. On the morning of the 14th, the squadron would be engaged against a strike force of Dornier Do 17 and He 111 bombers under escort by Bf 109Es. The D.520 of GC I/3 would claim six confirmed kills in the morning, two on He 111s, two on Dornier Do 17s and two on Bf 109s, plus a claimed but unconfirmed kill on another Bf 109. In the late afternoon, D.520s of the squadron would engage in combat against a flight of Bf 110 heavy fighters from ZG 26. As often when the Bf 110 was faced with single-engine fighters without backup from Bf 109s, this ended up fairly bloody for the German squadron which lost four planes, with an additional probable Bf 110 killed claimed by the French.

On the 15th, defence against German raids in the morning would see the squadron claim three confirmed and a probable Dornier Do 17 kills, as well as a confirmed Bf 110 and He 111. In the early hours of the afternoon, D.520s would claim one confirmed and two probable Bf 109s.

The squadron’s actions would wind down in the following days, as it retreated from its first airfield to a new one in Meaux-Esbly, closer to Paris. With German pressure now concentrating against the encircled French and British forces in the North, action would be more sporadic. Between the 15th of May and the 3rd of June, the squadron would claim confirmed kills on an He 111, a Bf 109 and a Do 17, as well as further probable kills for another He 111 and another Dornier 17.

From early June onward, with the Dunkirk pocket liquidated by German advance, attention would shift towards the south once again as Germany progressed further into France, while the French organized a fairly desperate defense on the so-called “Weygang Line.” On the 3rd of June 1940, the squadron claimed its first Ju 88 kill, as well as claiming another Bf 109, and probable shoot downs on three Dornier Do 17s and a Heinkel 111. The 5th and 6th of June were particularly intense in terms of combat with German fighters, with the D.520 claiming four Bf 109s and an Hs 126 on the 5th, and a further two confirmed and two probable 109s as well as a confirmed Do 17 on the 6th. The 7th saw the squadron claim a confirmed Do 17 and Bf 109, and two further probable Do 17s.

A flight of German Dornier Do 17Z during the Campaign of France. Variants of the Do 17, alongside with the slower He 111 and the lighter Ju 87, were the most common bombers encountered by the French air force in 1940. The fairly fast Dornier could prove hard to catch for the MS.406. The later MB.152 and Curtiss H75 were already more effective in such a task, but the D.520 was clearly the best equipped French fighter to deal with fast enemy bombers. [Asisbiz]
German soldiers pose in front of a shot down D.520 of GC I/3. This particular plane was flown by Lieutenant Clarisse and shot down on the 21st of May 1940, the pilot being killed. [ww2fighters.e-monsite.com]
The 9th of June 1940 saw the D.520 make the most claims of the Battle of France. The squadron was engaged against a raid of Dornier Do 17s escorted by Bf 109s around noon, claiming four fighters and a bomber. In the late afternoon, the squadron was engaged again against Dornier Do 17s and Junkers Ju 87s once again escorted by Bf 109s, seeing the French fighters down a confirmed Do 17 and Bf 109 as well as two Ju 87s, with a further two probable Do 17 and Bf 109.

The 9th of June 1940 would also begin to see the squadron retiring from its airfield near Paris to go further south, to avoid the now very threatening German advance on the ground. Though a further few engagements were fought fromt the 14 to 16th, most of the action was now behind the squadron. From the 17th to the 21st of June, the squadron would jump from airfield to airfield, from Southern France, to Algeria, finally settling in Kaala-Djerda and later Tunis-El Aouina in French Tunisia.

GC I/3 had claimed a considerable number of victories during the campaign, showing the qualities of the aircraft despite the general lack of training that was to be found in a squadron only recently introduced to its fighter. In total, the squadron claimed 55 confirmed and 19 probable victories. This was at the cost of 32 D.520s lost – of which 21 were lost in aerial combat, the rest being victims of either bombing runs or accidents. This was a rather decent success for a unit which had just received the new fighter type.

Other Squadrons

A number of other squadrons did receive the Dewoitine D.520 during the campaign and used it against German and later Italian forces.

A D.520 of GC II/3 in flight in 1940. The squadron’s emblem, a greyhound, can be observed on the tail. GC II/3 was the second most successful squadron flying the D.520 during the campaign of France. [ww2fighters.e-monsite.com]

The first squadron to receive D.520s after GC I/3 was GC II/3, which transitioned to the D.520 in 10 days from the 10th to the 20th of May. This was a very short transition for the new fighter, which many would imagine to be fairly worrying for the performance of the squadron. Nonetheless, GC II/3 would perform quite admirably during the campaign. Engaged heavily from the 20th of May onward, it would claim a single victory, an He 111, on its first day of combat, five confirmed and two probable victories on Dornier Do 17s, He 111s and Me 110s on the 21st, and ten confirmed victories (eight Ju 87s and two Hs 126s) on the 22nd. During the entire duration of the campaign, GC II/3 would claim 31 confirmed and 15 probable victories at the cost of 20 D.520s, though only three pilots were killed. The squadron notably counted on Czechoslovak pilot Cukr Vaclav, who would claim two confirmed kills and six shared kills, as well as French Capitaine Raymond Clausse, with three confirmed, and two probable kills on his own, as well as two confirmed, and two probable shared kills.

D.520 n°273, flown by GC II/7 in June of 1940. [ww2fighters.e-monsite.com]
D.520 n°119 of GC II/7, shot down on the 15th of June 1940. [ww2fighters.e-monsite.com]
Other squadrons received their D.520s later in the campaign and would see the fewer kills , among other factors, due to the D.520 being received later in the campaign, at which point German air superiority had more or less been established, and sometimes having to work in mixed squadrons that still incorporated slower Morane-Saulnier MS.406s. GC II/7 was one such mixed squadron, receiving their first D.520s around the 25th of May, while at the same time retaining Moranes until at least the 1st of June. The D.520s of the squadron would still claim more than a dozen victories at the cost of nine of their own aircraft.

GC III/3 fought the most intense parts of its campaign with MS.406s, but was refitted with the D.520 in late May, seemingly not engaged from the 20th of May to the 5th of June, during the transitional period. Going back into action with the Dewoitine, pilots of the squadron would go on to claim eight confirmed, and one probable victory in June, with three confirmed Bf 109s shot down, and another probable, one each of the He 111, Me 110, Dornier Do 17, and two Hs 126s.

Pilots of GC III/3 plot their next mission on the tail of a D.520, June of 1940. [AeroVFR.com]
GC III/6 is one of the most well known of the D.520 squadrons despite receiving the aircraft late into the campaign. By mid-June 1940, the squadron was in the process of converting from the MS.406 to the D.520, when the entry of Italy into the war forced it to be put into action against Italian aircraft. Under these conditions, French pilot Capitaine Pierre le Gloan would first shoot down two Fiat BR.20 bombers on the 13th of June. On the 15th, Le Gloan took off on a routine patrol around 11:45 pm, originally comprised of three Dewoitines, but soon reduced to two due to technical issues of one aircraft forcing it to return to base. The two remaining fighters, operating near Saint-Tropez on the Mediterranean coast, encountered a force of twelve Fiat CR.42 biplanes of the Italian squadron 23e Gruppo CT. The two D.520s engaged the biplanes. Le Gloan damaged two, one that caught fire and was later written off, and the other pilot ejected, before the faster French fighters broke off. Le Gloan’s wingman’s guns jammed, forcing him back to base as well. Not content with merely two CR.42 shot down though, Le Gloan encountered a further patrol of CR.42s from 18e Gruppo, shooting one down before evading the others in a dive using the largely superior speed of the 520. Le Gloan then returned to Luc airfield, where GC III/6 was stationed, shooting down a CR.42 attempting strafing runs. Lastly, he would down a BR.20 attempting photo reconnaissance of the airfield, attempting to identify the effects of Italian strafing. The Dewoitine was out of cannon ammunition by this point and the BR.20 had to be shot down by machine-gun fire, requiring a total of five passes. This action would have been sufficient to make Le Gloan an ace not just in a day, but in a single sortie, though he had already scored two victories previously. While it was performed using the higher speed of the D.520 against slower biplanes, which would not effectively pursue the French fighter, it remains an impressive feat and likely the most famous action of the D.520 during the campaign of France. Le Gloan’s victories also appear to be the only confirmed ones scored by GC III/6 with the D.520.

A D.520 of GC III/6 during the Battle of France. [ww2fighters.e-monsite.com]

Two other French army squadrons, GC II/6 and III/7, began transitioning to the D.520 in June but could not be made operational on the aircraft in time to meaningfully take part in the Battle of France. This was also largely the case for two ground-based squadrons of the French navy’s Flottile F1C, AC 1 and AC 2, which received a few D.520s in the later stages of the Battle of France.

The Tricolor Cockade and the Balkenkreuz: Dewoitine versus Messerschmitt

A topic which inevitably comes up when discussing the D.520 is its comparison with the mainstay German fighter at the time, the Bf 109E. This comparison has been a considerable subject of debates, particularly in France, where a significant amount of pride has often been instilled in the D.520 as the only modern indigenous French fighter that saw intense action and was able to challenge the German fighter.

In practice, the duel between the two aircraft was a rather complicated matter – which was known to the French air force, as a Bf 109E captured during the Phoney War was quite extensively tested in comparison to the D.520 in April of 1940.

A Bf 109E-1, previously of JG 76, which was forced to make a landing in France in November of 1939 and was subsequently tested by the French. [asibiz]
The Bf 109 had a clear climb rate advantage over the D.520, which was particularly felt at low altitude, due to being better engined than the French fighter, which was sometimes found to be lacking in horsepower. German engine cooling was also found to be superior, which allowed the aircraft to run for longer at full throttle, while French pilots would often have to temporarily limit running the engine at full throttle to avoid overheating. This would usually allow the German fighter to dictate the terms of engagement, but considering the mostly defensive use of the D.520s, the Bf 109s were forced to provide cover to German bombers, and were often operating in escort, and not air superiority sweeps.

Where the D.520 is often said to have had an advantage is in maneuverability. The D.520 had the advantage of more subtle and less abrupt controls in comparison to the Bf 109E, which would typically give an advantage to the French fighter in a prolonged dogfight. The Dewoitine also enjoyed good engine torque, and in comparison to the BF 109E the cockpit of the D.520 offered far greater visibility which would prove an advantage in such a situation. This was not, however, a massive advantage, and the comparative trials held in April of 1940 saw a duel typically last for several minutes before one of the two aircraft could mount an advantage over the other. In turning fights, the D.520 had a known issue where it was vulnerable to stalling and temporary loss of control during some turns. This was an issue if the enemy fighter was in a favorable position at the moment, though in some engagements it was found that the stalling could be used as an evasive maneuver if the enemy fighter was at a considerable speed advantage. In general, the D.520 was found to still be more comfortable to pilot than the 109 in prolonged dogfights. In turnfights, the D.520 would typically win when the turns were towards the right, but the Bf 109 could be expected to win those towards the left.

In general, while French patriotism would encourage many French authors to claim the D.520 as equal or sometimes even superior to the Bf 109, in practice, the German fighter could arguably be claimed to usually have a slight edge – its ability to dictate the terms of engagement was not entirely compensated for by the maneuverability of the French fighter. This, however, does not paint the full picture. While one may ponder at length over whether the D.520 could be considered equal or slightly inferior to the Bf 109E, it remains clear that it was highly superior to the pre-existing fighters in the French air force, such as the Curtiss H75, Bloch MB.152, and particularly the Morane-Saulnier MS.406, when it came to intercepting fast German bombers such as the He 111, and particularly the Do 17 and Ju 88. The MS.406, notably, would often struggle to catch up with German bombers, while the D.520 could do so relatively easily – giving the French air force a far better tool against enemy bombers, though obviously one which arrived way too late. As such, the D.520 represented a major improvement in the capability of the French air force – which would have been further reinforced by additional new fighter types entering service in June of 1940, the Bloch MB.155 and Arsenal VG.33, with the later managing even better performance than the D.520, with a less powerful engine of the same type, and likely offering a serious competitor to the Bf 109 and Spitfire had the war not abruptly interrupted for the French Third Republic.

An Arrow through the Cockade: Vichy’s Workhorse

Absolutely defeated on the ground by a better equipped, led, and coordinated German army, France was forced into an armistice with Germany, negotiated on the 22nd of June 1940 and going into effect on the 25th of June 1940. In this Compiègne Armistice, the Third Reich inflicted on its French archenemy what was, in many ways, a revenge and repeat of Versaille, with the French as the victim, seriously limiting the size of the French army and its ability to produce new equipment.

However, strategic requirements are a more important matter than symbolism. The French government was in control of many colonial areas around Africa and Asia which Great-Britain was now interested in seizing to further their situation and, with the sinking of the French fleet of Mers-El Kébir on the 2nd of July 1940, this set a major precedent of hostility between the new French regime and the British. Under these conditions, allowing the new Vichy French government to retain a military that could offer resistance to British and Free French attempts to seize colonial territories and naval assets was a useful prospect for Germany. As such, France was allowed to keep a number of squadrons and military units operational – most notably in French North Africa and the French Levant, but also Metropolitan France to an extent.The air force was allowed more strength than the army, which could not operate any armored vehicles outside of Panhard 178s downgraded to a machine-gun armament in mainland France.

D.520 n°277 of GCIII/6, the personal plane of French ace Pierre le Gloan, in flight in French North Africa during the early months of the Vichy regime. One can observe the identification arrow, which in this case extended all the way to the propeller hub, but on other aircraft stopped around or slightly in front of the cockpit. [ww2fighters.e-monsite.com]

Dewoitine D.520 of GC III/7 in Chateauroux, France, August 1940. The planes are yet to receive any Vichy identification markings and were likely not used operationally at this point. [Pinterest]
As such, authorization was given for the Vichy regime to maintain squadrons I/3, II/3, III/6, II/7 and AC1 operating the D.520. All would be stationed first in French North Africa, with all being located in Algeria outside of II/7 operating in Tunisia. The motive behind putting Vichy’s best fighters in French North Africa was that this location was now the most valuable colony still in the hands of the regime, and was much more vulnerable than the French mainland to potential attack attempts by the Allies. At the same time, while the D.520’s range could allow it to comfortably ferry over the Mediterranean and generally operate in a theater where longer ranges could be desirable, Vichy did retain a number of squadrons operating the shorter-ranged Bloch MB.152 in Metropolitan France. With the Bloch fighter unable to reasonably make the crossing, and ill-equipped to reasonably protect French North Africa, the D.520 was pretty much the only possible choice outside of a now incredibly outdated MS.406 that was on its way out of Vichy’s air force.

During their service life, Vichy aircraft were given a number of recognition markings to differentiate them from British or Free French aircraft and avoid friendly fire incidents from German or Italian planes. At first, this manifested in the form of a white line going through the rear and center of the fuselage, with the cockade superimposed on top and an arrowhead in the direction of the front of the plane. This was put on from the late summer of 1940 onward. From early 1941 onward, these were judged insufficient to reasonably identify Vichy’s aircraft, and they saw their tail sections and propeller hubs painted yellow to further ease identification; it is with these identification markings that the Vichy D.520 would fight during the Levant campaign in May of 1941. In the summer of 1941, the recognition markings were pushed even further, with orange stripes included within the yellow sections, and in many cases, parts of the engine cover painted in the same yellow and orange scheme as the tail.

A magnificent colorized photograph of GC III/6 D.520 fighters. This photo was taken at Eleusis airfield, Athens, in May of 1941, a refueling stop for the French fighters heading to the Levant. It gives a formidable view of the D.520’s camouflage, the yellow tail section, and the identification arrow. [Flickr]
A good view of a Vichy D.520 in the markings which were now standard by 1942, with the white identification line no longer featuring an arrowhead, and yellow-and-orange stripes on the empennage and engine fairing. [Asibiz]
In April of 1941, with German approval, production of the D.520 resumed to fulfill an order for 550 new planes for Vichy’s air force. The goal was now to make the D.520 the standard fighter of the French air force to the greatest extent possible, first replacing the MS.406 in the squadrons then operating it, and in the further future the MB.152 and MB.155 operated by the fighter groups in Metropolitan France. Two new fighter groups operating the D.520 were created, GC I/2 in Châteauroux, Metropolitan France, and GC II/6 intended for French Occidental Africa, while four squadrons operating other types were re-equipped with the D.520 in Metropolitan France, these being GC I/1, GC III/9 and GC II/1. The last squadron, GC II/5, located in Casablanca, Morocco, was in the process of switching during the Allied invasion of French North Africa, Operation Torch, in November of 1942.

A number of Dewoitine D.520 fighters in the SNCAM-Dewoitine factories of Toulouse/Saint-Martin-du-Touch in 1942. The planes are now being completed with the identification white band, the arrowhead no longer featured, and with the orange and yellow sections at the empennage and around the engine block. [ww2fighters.e-monsite.com]
In a fairly cruel twist of irony, what was once the only fighter able to offer resistance to Germany’s Luftwaffe, by 1940 now flew for the Vichy Regime, and only truly became the most common French fighter under this collaboration government. The D.520 would see considerable action in defending Vichy’s colonial territories against British, Free French and American intervention, now fighting a whole different set of aircraft. However, this would once again be under lackluster conditions; pilot training under Vichy was not as extensive and long as under the pre-armistice conditions, partly due to lack of fuel restricting the flight hours which would be performed. While the pilots who fought under Vichy during the Levant campaign and Operation Torch had had more time to accustom themselves to the D.520 than those flying during the Battle of France, these were often the same men from the same squadrons which had now made the switch to the D.520 during the Battle of France. They flew fewer hours per year overall, and as such had their skills not as “well maintained” as their Allied counterparts that were regularly flying combat missions against the Regia Aeronautica and Luftwaffe over North Africa and the Mediterranean.

Another view of the Toulouse/Saint-Martin-Du-Touch facilities, showing the considerable industrial effort by Vichy at manufacturing the D.520. Still present in only moderate numbers in the Battle of France, it is only under Vichy that the D.520 would truly become the mainstay fighter of the French air force. [aérothèque.com]
Under the Vichy regime, studies were also performed in outfitting the D.520 with more powerful engines in order to make the Dewoitine a viable fighter for later in the war. This resulted in the D.520Z, fitted with a Hispano-Suiza 12Z 1,600 hp engine. This project would result in work on a prototype, completed in February of 1943 with German approval, but would only fly in 1947. A project modernizing the D.520 further, the M.520T, would never even reach prototype stage. Vichy had hoped the D.520Z would be serially produced, and postwar trials indeed indicated the fighter had respectable performance even by mid-war standards, being able to reach 659 km/h at 9,150 meters, and could climb to 4,000 meters in 4 minutes 10 seconds, to 8,000 meters in 8 minutes 22 seconds, and to 11,000 m in 14 minutes 19 seconds. This was a very significant improvement in comparison to the D.520, though it came at the cost of the 12Z being a sometimes unreliable engine that would require a lot of maintenance. The occupation of the Vichy regime would prevent any further development, despite a production of up to 230 having been hoped for in the middle of 1942.

A view of the D.520Z prototype postwar. Had production been undertaken in the mid-war, the D.520Z would have been a decent fighter, but by the post-war era, it could only really be used as a testbed. [Pinterest]
A profile view of the M.520T. While on the loose technical basis of the D.520, it would in many ways have been a new aircraft. [War Thunder Forums]

Dewoitines Against Hurricanes: The Levant Fiasco

On the 1st of April 1941, a coup in previously British-influenced Iraq brought to power a pro-Axis government, the Golden Square, which would result in the Anglo-Iraqi War lasting for much of the month of May. Germany and Italy, eager to use this opportunity to open another front against the British Empire in the Middle-East, pushed Vichy France to allow Axis planes to use the French colonies of Syria and Lebanon as a base to get to Iraq and support their troops against British Commonwealth forces.

After the end of this campaign, this breach of Vichy’s non-belligerence in favor of Axis support would lead to British, Australian, Indian, and Free French troops invading the Vichy colonies of the Levant. The Vichy regime attempted to put up a defensive effort, which, in the air, relied on Dewoitine fighters.

Prior to May of 1941, only the older MS.406 were located in Levant. With the rise of tensions as the colony now hosted Axis planes, GC III/6 was relocated from Algeria to Rayack in Lebanon on the 27th-28th of May 1941. This airfield would be used until late June, when the squadron would move to Alep. During the Levant campaign, GC III/6 would be joined by GC II/3, which moved into the Levant, transiting through Axis-occupied Greece and would operate from Homs and later Alep during the campaign. The French Navy’s AC 1 squadron would be deployed to the Levant as well.

The opposition the French would face consisted of Hawker Hurricane and Curtiss Tomahawks (P-40), as well as occasionally older Gloster Gladiators, escorting bomber formations typically composed of Blenheim bombers.

Dewoitine D.520 N°383 of GC III/6 at Rayack airfield, Lebanon, May 1941. The aircraft features the yellow recognition tail as well as a recognition arrow stopping in front of the cockpit. This aircraft, flown by Capitaine Rival Mazières, second in command of GC III/6, was shot down by British Curtiss Tomahawk fighters on the 23rd of June 1941 with the pilot, at this time Sergent Savinel, killed. [ww2aircraft.net]
The mangled wreck of the same Dewoitine, shot down on the 23rd of June 1941. [joseph bibert fichiers]
The French squadrons put up considerable opposition in the air, with the D.520 still being a decent adversary for the fighter aircraft they were facing. GC II/3’s scoreboard was fairly moderate, with two Blenheims and a Tomahawk shot down on the 2nd of July, with one confirmed and one probable Tomahawk on the 11th of July. GC III/6, present in the operations for longer, would feature a much more accomplished score-board during the campaign. They claimed 16 confirmed and 2 probable Hurricanes, a Fulmar, a Maryland, a Tomahawk, and three Gladiators. Pierre le Gloan, still flying with GC III/6, claimed seven victories: six Hurricanes and a Gladiator. As for the Navy’s AC 1 squadron, it would claim seven confirmed and one probable kill.

Though these were some considerable victories, the D.520 suffered some significant losses during the campaign, with about 40 planes lost, though only eight pilots were killed. Most of these were not shot down in flight. The issue the French faced in Levant were limited aviation facilities that featured little to no anti-aircraft defenses. Against a considerably numerically superior adversary, this resulted in the French being unable to defend their airfields against strafing runs, which decimated the fleet of Dewoitine aircraft. As British forces were progressing through the region swiftly, the three D.520 squadrons were redeployed to Algeria transiting through Greece in early July, so that the remaining fighters, and most importantly their pilots, could participate in the defense of French North Africa, now that the French Levant was irredeemably lost.

A Navy D.520 during the early Vichy area. The aircraft’s branch can be identified by the anchor present on the rudder section. [Cols bleus : hebdomadaire de la Marine française, French Navy, September 1985]
It should be noted that two D.520s left behind by Vichy’s air force in the Levant would be captured by the Free French and re-used for a short while in order to train the pilots of Free French GC 3 “Normandie.” This squadron would, from late 1942 onward, be deployed to the Soviet Union, operating with great success using Soviet Yak fighters for the remainder of the war, and gaining great fame as the only Western Allied fighting unit on the Eastern Front, and a highly successful squadron by both Free French and Soviet standards. Previously, the Free French had operated three D.520s that had defected from France to England in June of 1940. Two were conscripted into the force which attempted to seize Dakar in September of 1940, and following the failure of this attempt, they were unloaded in French Equatorial Africa, a colony which joined the Free French. One was lost in an accident, and the other left at its airfield when Free French pilots moved to Egypt to be equipped with Hawker Hurricanes.

Dewoitine D.520 n°302, one of the two D.520s captured by the Free French in the Levant. The two fighters were used by GC 3 Normandie before it moved to the USSR and eventually became the famous “Normandie-Niémen”. [warisboring.com]
The Free French D.520 n°139, by this point in time the only one in service, preparing for take-off in Chad, January of 1941. [ww2fighters.e-monsite.com]
 

French Droplets on the Torch

A Vichy D.520 of an unidentified squadron in French North Africa, 1941. [ww2aircraft.net]
In November of 1942, with the war in the desert in Libya clearly going to the advantage of the Allies, French North Africa appeared as an increasingly appealing territory to seize to further the position of the Allies in North Africa. The large colony, comprising Morocco, Algeria and Tunisia, was however fairly well defended, with the heaviest military forces still in the hands of the Vichy Regime located there. In terms of squadrons using the Dewoitine, these being GC I/3, II/3, III/3, III/6, II/7 and AC 1.

The Anglo-American landings were performed on the 8th of November. For air cover, they relied on large numbers of Grumman F4F Wildcat/Martlet and some Hawker Sea Hurricanes, which were still fighters the D.520 could hope to challenge – and the French squadrons did put up some considerable opposition to Operation Torch.

US Navy F4F Wildcat aboard USS Ranger CV-4 during Operation Torch. The American carrier fighter was about a match for the D.520, with a fairly similar maximum speed, likely slightly superior manoeuvrability but lower climb rate. [World War Photos]
GC I/3, operating near Oran, racked up a considerable score on the 8th of November, shooting down six Fairey Albacore light naval bombers, five Douglas C47 transport planes, five Hurricanes or Sea Hurricanes, and even a Spitfire. GC III/3, operating near Oran, appears to have claimed nine victories for seven D.520s lost. GC II/3, III/6 and II/7 were not located in areas as hot as the major Algerian harbour of Oran, and appear not to have claimed any victories during the battle. The French Navy’s AC 1 operating in Morocco claimed two F4F Wildcats for no aerial losses.

A D.520 of squadron 2AC of Flottila 1F on the runway in French North Africa, 1942. [ww2fighters.e-monsite.com]

However, while the French Dewoitines could still put up quite a fight against an F4F in the air, the numerical superiority of Allied fighters, and lack of French airfield defences would once again come back to haunt the French air force, with the AC 1 losing 19 of its 27 D.520s against strafing and bombing runs during the three-days of fighting during Operating Torch.

Luckily for the French, the colonial authorities of North Africa swiftly decided not to continue a vain opposition to Allied advances, and instead sided with the Allies against the Axis. With this, the Vichy squadrons, comprising a little over 130 D.520s, were now fighting against Axis troops. One was repainted in American colors and tested by the US Army Air Corps.

However, the end of the service of the D.520 in North Africa would be fairly swift, with the squadrons soon refitted with fighters such as Hurricanes and Spitfires for further operations, the D.520 no longer being seen as an up-to-date fighter and they lacked the facilities in France likely necessary for the manufacture of spare parts. The Dewoitine was relegated to a training role, in which it was still used in early 1944.

A flight of Free French D.520s over North Africa, early 1944. The planes received a roundel, and no other markings. Due to their operation in an area now void of Axis activity, no risk of confusion with an aircraft of a now nonexistent Vichy air force was considered. [joseph bibert fichiers]

Case Anton: The Dewoitine Under the Balkenkreuz

Days after French North Africa was invaded by the Allies, attention would now turn to the unoccupied part of France under the jurisdiction of the Vichy Regime. On the 11th of November 1942, Germany launched Case Anton, the Wehrmacht rushing to take control of Southern France, facing no resistance from Vichy troops that had been ordered to stay in their barracks and not oppose the Germans invaders. With this swift move, Germany captured around 250 Dewoitine D.520 fighters as well as the facilities which were in the process of producing more.

D.520 n°95 of JG 101 at Pau airfield, France, 1944. The German D.520s were repainted in a camouflage fairly similar to what could be found on other German aircraft by that point in the war. [Asisbiz]
The French production facilities would continue to work during German occupation, albeit at a reduced rate, seeing as the D.520 was a very low priority by late 1942. About 60 further fighters would be completed under German occupation.

Within the Luftwaffe, the D.520 was put to use as a trainer aircraft. Though now obsolete as a frontline fighter, it could still provide a decent introduction to modern, metal monoplanes with retractable landing gear. For this purpose, JG 101 was outfitted with the D.520 and operated in occupied France, mostly from Pau, in the South, where it would be free from sweeps and raids performed from the British Isles. JG 103, operating during the remainder of the war in the Netherlands or Austria, also used the D.520, as did JG 105, operating near Paris and Chartres, and JG 107 in Nancy. In German service, the D.520s were painted in a light gray color with darker gray spots on much of the aircraft, something typically found on many late-war German aircraft. The underside of the aircraft, and in some cases the nose and tail sections, were painted in a garish yellow color, likely for identification purposes as a training aircraft. The planes received a Balkenkreuz marking on the central fuselage and a swastika on the tail.

German maintenance crews at work near a D.520 in occupied France. [Pinterest]
The D.520 was noted to not always be a very easy plane to pilot, as it had some unforgiving flight characteristics and suffered from some mechanical issues, such as landing gear which at times failed to retract completely. However, in comparison to German fighters of the time, it offered much smoother and lighter controls for the pilot in comparison to the now quite heavy Bf 109G which were being operated by this point. There would nonetheless be several accidents, with at least three German pilots killed and two wounded on the Dewoitine. A number were also destroyed by Allied bombings of French airfields used by the Luftwaffe.

Outside of a training aircraft, there was another use the Germans could find to the D.520 by the second half of the war. It offered a convenient ‘hand-me-down’ aircraft to outfit the air forces of Axis states which requested fighters from Germany, without diverting any frontline German fighters being manufactured by this point. Two German allies would be outfitted with considerable numbers of D.520 in this fashion, Italy and Bulgaria, though it is sometimes claimed some outfitted Romania as well.

The French Fighter of the Regia Aeronautica

The Regio Esercito (Italian Army) captured 30 Dewoitines during the Battle of France, with many more being transferred to Italy after German capture in France.

The D.520s were assigned to various Regia Aeronautica (Italian Air Force) fighter groups, tasked with intercepting American bombers in the defense of various major cities, an endeavor which was met with mixed results. As Italy began to fall, some Dewoitines were destroyed by retreating Italians, or recaptured by the Germans.

It is of note that the Italians regarded the D.520 largely inferior for various reasons, but did praise the aircraft’s armament, making mention of the formidable 20mm cannon.

Regia Aeronautica D.520 of an unidentified squadron. The planes have by this point received Italian markings, such as the cross and the white band, but the base camouflage appears to remain the one featured on the original French planes, outside of perhaps the red propeller hub. [Pinterest]

The Shield of Bulgaria

A magnificent view of a Bulgarian D.520 in front of a mountain range. The camouflage used by the Bulgarian air force was similar to the Luftwaffe’s, but using Bulgarian markings and stripping their planes of any garish yellow paint. [Pinterest]
The other Axis air force which received a large number of D.520s was the Bulgarian Air Force. Though a member of the Axis powers, Bulgaria had chosen to remain out of Operation Barbarossa, and to not declare war on the Soviet Union, with its contribution to the war effort mostly consisting of its occupation of parts of Greece and Yugoslavia as well as economic cooperation with the Reich. As such, providing fighters for the Bulgarian Air Force may have seemed to be a lower priority for Germany in comparison to other allies, such as Hungary and Romania, which were actively fighting on the Eastern Front. However, Bulgaria was nonetheless at war with the Western Allies and, from 1943 onward, the subject of air raids increasing in frequency and intensity.

The D.520 seemed to be an appropriate hand-me-down for this lower priority but not insignificant part of the Axis, especially as the aircraft, while obsolete against modern fighters by 1943, could still be used against bombers and Bulgaria was still mostly out of reach of Allied single-engined fighters. Up to 150 D.520s appear to have been offered to Bulgaria, of which 120 would be ordered and 96 effectively delivered, the first 48 in August of 1943.

6th Fighter Regiment D.520s at a hangar at Karlovo airfield, Bulgaria, September of 1943. While the Avia fighters which shared the same engine family as the D.520 were no longer frontline fighters by this point, the experience gained by Bulgarian mechanics working on them likely simplified the transitional period to the D.520. [ww2fighters.e-monsite.com]

A major advantage of the D.520 for Bulgaria was that the old Czechcoslovak fighters already in use by the Bulgarian air force, the Avia B-71 and B-135, already used engines of the Hispano-Suiza 12Y family, albeit older models. This meant that Bulgarian mechanics would already have some experience with engines similar to those found on the Dewoitines, and that some amount of parts commonality could be expected, easing the logistical burdens Bulgaria would suffer in comparison to obtaining a fighter with an unrelated engine.

The Bulgarian Dewoitines were painted in schemes generally similar to the German ones, with a light gray base, dark upper, along with mottled spots in between. They, however, made more use of brown and green colors as well. The cross of the Bulgarian air force was painted on the aft fuselage, with the individual fighter number behind it. A yellow or white band was sometimes featured in front of the cross, behind the cockpit. The tips of the wings and sometimes the propeller hub were also painted in yellow.

The Bulgarian Dewoitines were delivered to the 6th IP (Fighter Regiment), where they formed the core of the 1st and 2nd groups. They would be operated in intercept missions, fighting along with Bf 109G-2 fighters also operated by the Bulgarians. American raids at this time typically consisted of B-24 bombers escorted by P-38 twin-engine fighters. While these escorts were significantly faster and better armed than the Dewoitines, the Bulgarian fighters could still count on their superior maneuverability to avoid being shot down. It appears the first victories by Bulgarian Dewoitines were scored on the 24th of November 1943, when three to four American planes were shot down by a Bulgarian fighter force composed of 24 D.520s and 16 Bf 109s. The first loss in combat appears to have been on the 10th of December, when one of 22 D.520s flying to intercept a flight of 60 B-24s and 60 P-38s was shot down. Ten days later, on the 20th, D.520s would score two victories, including an escorting P-38. On the 10th of January, Bulgarian pilots, flying 23 D.520s and 16 Bf 109s, in cooperation with 30 German Bf 109s, would claim four B-17s and four P-38s for the loss of a D.520.

Bulgarian air force personnel in front of a D.520 at Karlovo airfield in 1943. The D.520 would form a considerable portion of the Bulgarian air force’s fighter complement in late 1943 and early 1944, though it would progressively be superseded by the more modern Bf 109G. [ww2fighters.e-monsite.com]
The 30th of March 1944 saw the largest air raid of the war on Bulgaria, with more than 360 B-17s and B-24s attacking Sofia. The Bulgarian air force scrambled all aircraft it could muster, including some Avia B-135s from training schools in addition to 28 D.520s from the first group of 6th Fighter Regiment (I/6) and 6 from the 2nd group (II/6). The Dewoitine-equipped groups claimed a B-17 for I/6, and two bombers and a P-38 for II/6. By this point however, losses were starting to increase for Bulgarian fighters, with 4 to 5 D.520s lost against P-38s and defensive fire from the bombers. By the spring of 1944, American air raids now included P-51 and P-47 escorts in addition to the P-38, further complicating the task of Bulgarian pilots. The D.520s appear to have been falling out of favor in comparison to Bf 109s for interception purposes by this point. While 44 Dewoitines were still available to the Bulgarian air force on the 1st of May 1944, they would claim their last victory on 5th of May with a B-17 shot down. Losses started to mount at this point, mostly due to bombing runs against Bulgarian airfields as well as lack of spare parts to support continued operation. By the 1st of September 1944, only 32 D.520s were still in Bulgarian hands, with only about half in flying condition. Overall, the D.520s appear to have claimed 5 B-17s, 2 B-24s and 4 P-38s, attacking in intercept missions against the USAAF, at the loss of seven D.520 in combat. Eight to ten were actually lost in accidents, and overall, eight Bulgarian pilots were killed flying the Dewoitine.

Bulgarian air force personnel of the 6th Fighter Regiment in front of a row of parked D.520s. [ww2fighters.e-monsite.com]
As Soviet forces reached Bulgaria, a communist coup took over on the 9th of September 1944 and Bulgaria joined the war on the side of the Soviet Union. Remaining Bulgarian D.520s would operate against German forces from September to November, with a further two planes being lost, before the type was sent away from the frontlines in November of 1944. D.520s would remain in use by Bulgarian flight schools until 1947, when the type was finally retired from the service of the Bulgarian air force, and surviving aircraft were scrapped.

Bulgarian air force cadets stand on a D.520 during the plane’s last year of service in Bulgaria, 1947. [ww2fighters.e-monsite.com]

The Dewoitine into Liberation

By the 6th of June 1944, the D.520 was no longer used as a frontline fighter by any air force in the West. The Luftwaffe and Free French air force both operated the type as a trainer, with many of the Luftwaffe’s fleet of Dewoitines based in France.

While in the first two months following Operation Overlord, Allied progress would remain fairly slow and confined to Normandy, the breakthrough of Operation Cobra in late July saw a lightning-fast liberation of France by a combination of Allied mobile troops, and uprisings by the Forces Françaises de l’Intérieur (French Forces of the Inside or FFI) the leading organized French resistance. This would result in many D.520s being left behind on overrun airfields.

A first use of the D.520 by the FFI would be by a group of resistance fighters taking over the German occupied airfield at Châteauroux on the 20th of August 1944, where they found several damaged aircraft. Cannibalizing parts from different planes, the FFI managed to repair a single Dewoitine. Repainted in French colors, with a Cross of Lorraine on the tail, a French flag on the empennage, and “FFI” painted on the central fuselage, the Dewoitine was flown by a pilot that had not flown since the Battle of France, but ended up belly-landing. Two days later, German troops fleeing Southern France temporarily occupied Chateauroux again, with the FFI camouflaging their plane, and going into hiding until German forces finally left on the 10th of September.

The belly-landed FFI D.520 of Chateauroux, 27th of August 1944. [ww2fighters.e-monsite.com]

A more organized and professional use of the Dewoitine by the Free French, or French Forces of the Interior (FFI) would be accomplished by the Marcel Doret fighter group. Following the Allied Landings in Provence on the 15th of August 1944, much of Southern France was liberated by Allied troops and FFI uprisings in the following days, including at German airfields in Southern France, the facilities of the Morane-Saulnier, the SNCASE-Dewoitine factories in Toulouse, and the surrounding area. This resulted in a considerable number of Dewoitines falling into the hands of the FFI, which would very swiftly put them to use. Under the command of Marcel Doret, the most prolific French test pilot in the pre-war era, a fighter group was established, operating two squadrons of D.520s, one in Toulouse and one in Tarbes, both in Southern France. This group was grown as the “1er Groupe de Chasse FFI” (1st FFI fighter group), or more colloquially as the “Doret group”. It appeared to have had a strength of 18 D.520s.

Doret fighter group D.520s in late 1944. This photo shows how different markings co-existed at the time. The aircraft towards the left features a Cross of Lorraine on the tail and “FFI” inscribed within the invasion stripes, which the aircraft to the right as well as the one in the background lack. [Association des Amis du musée de l’Air]
A Free French D.520 with an unusual-looking, dotted camouflage pattern. [ww2fighters.e-monsite.com]
 

The Doret group was officially dissolved on the 1st of December 1944 – in practice, it was integrated into the formal structure of the French army as GC 2/18 “Saintonge.” The group was deployed to the Western French coast and used in recon missions as well as escorting Douglas A-24 Banshee bombers over the remaining German “pockets”, areas on the coast which remained under German control due to the presence of highly fortified U-Boat bases the Allies preferred to blockade, rather than attempt a costly take-over. In February of 1945, the D.520s were transferred to GC I/18 Vendée, continuing to see use in similar operations. This fighter group, the last operating the D.520 as a frontline fighter, was dissolved in October of 1945.

The camouflages used by the FFI were based on the German camouflages the D.520 were found with when captured, meaning a lighter gray base with darker gray spots. In some cases, the same brown as present on the D.520 previously in the service of the French air force was reintroduced on parts of the plane. Green could sometimes also be found. The FFI repainted the plane’s tail control surface with the French flag, as found on French air force aircraft prior to the armistice and the capture of the French fighters. A red cross of Lorraine was often found in the white stripe of this tail making. In the first months of operation, the D.520s also received the black and white invasion stripes in order to avoid any form of friendly fire incidents. In some cases, “FFI” appears to have been written in black letters in the white parts of the invasion stripes on the central fuselage. The D.520s also received French roundels on their wings, and later had their invasion stripes removed, with the space left on the central fuselage used for another roundel. A number in a circle was also present on the tail of many aircraft for identification purposes.

GC I/18 “Vendée” D.520s in flight in the spring of 1945. [WWII aces e-monsite]
A number of FFI D.520s were also exhibited during an aviation exhibition in Paris in the spring of 1945.

D.520s exhibited on the Champs-Elysées, Paris, Spring of 1945. [ww2fighters.e-monsite.com]

The Undying Trainer

One would expect the conclusion of the war to finally have buried the old D.520, by this point completely obsolete against modern prop fighters, let alone jets. Nonetheless, the plane saw continued use in the training role it had often been relegated in the later phases of the war.

This trainer role saw a final variant of the D.520 be designed and produced, the D.520 DC, double commande (dual control.) As the name suggests, this was a D.520 with an extended cockpit to the rear, intended for two men, a cadet and an instructor. The plane would receive dual controls allowing the instructor to take over control of the plane.

The unusual-looking D.520DC trainer conversion seen in 1946. This plane is D.520 n°243, the first of the 13 D.520DC, arguably the “prototype” of the series of conversions. [ww2fighters.e-monsite.com]

The modification had been devised by a French air force adjutant, with a first D.520, n°243, converted in the autumn of 1945. This was a very much makeshift conversion, using pedals from an Fw 190, a control stick from a no longer flyable D.520, and seemingly a seat from an A-24 Banshee for the instructor. Nonetheless, after a first flight in October of 1945, impressions were positive, and after a few modifications were performed, a dozen of D.520s were converted to the DC standards in early 1946. These planes would be used to train a number of French air force cadets, including the first few women to obtain military pilot licenses in the French air force.

The training service of both DC and single-seat D.520s would continue in the following year, though the type was progressively retired as more modern aircraft, including jets, were introduced. The last flight of a D.520 in the French air force was performed on the 30th of September 1953.

Surviving Aircraft

A D.520 is present on static display at France’s Musée de l’Air et de l’Espace du Bourget (ENG: Museum of Air and Space of the Bourget) near Paris. It is painted as a fighter of GC III/6, the squadron of the type’s most successful pilot, Pierre le Gloan.

A restored D.520 in GC I/3 camouflage. [le blog du lignard]
A D.520 in flyable condition is currently in the hands of the Conservatoire de l’Air et de l’Espace d’Aquitaine (Air and Space Conservatory of Aquitaine). It was restored to airworthiness from 2005 onward, after having been in storage for decades. A third D.520 is present in a hangar of the French navy, awaiting restoration alongside a number of other aircraft.

A fourth D.520, n°408, was part of the Musée de l’air et de l’espace as soon as it was phased out of service in 1957. Surviving as a warbird, it tragically crashed in July 1986, killing the pilot.

Variants

  • D.520-01 – The first prototype, utilizing a Hispano-Suiza 12Y-21 generating 890hp. No armament fitted. Numerous modifications included changes to the radiators, tail, exhaust, a 12Y-29 engine, and propeller.
  • D.520-02 – A fully armed prototype. Implemented all prior modifications, along with improved landing gear, and a larger empennage.
  • D.520-03 – Prototype with upgraded 12Y-31 Engine
  • D.520 – Main Production Version, fitted with the Hispano-Suiza 12Y-45 engine. Around 900 produced.
  • D.521 – Prototype utilizing the British Merlin III Engine.
  • D.522 – Version fitted with the slightly older Hispano-Suiza 12Y-31, fitted with a new Hispano-Suiza supercharger, providing better high-altitude performance. Production was scheduled to start in July 1940, but never occurred due to the German invasion of France.
  • D.523 – Fitted with the improved Hispano-Suiza 12Y-51 mated to a Sydlowski-Planiol supercharger, producing up to 1,000 hp at altitude. Also offered significant speed and climb advantages over the original D.520. Only one prototype produced.
  • D.524 – Scheduled for 1940 production, would have used the Hispano-Suiza 12Z engine, a refined version of the 12Y engine, expected to have produced 1,300 hp. None built.
  • HD 780 – Prototype floatplane naval version of the D.520 featuring foldable, angled, gull wings, increased engine size, and two floats. Was completed in March 1940 but never flown.
  • D.525 – Combined the Hispano-Suiza 12Y-51 engine with the Hispano-Suiza supercharger used on the D.522. Only 30 produced.
  • D.520Z – Produced under the Vichy Regime in 1943 with German approval, this prototype installed the Hispano-Suiza 12Z engine, making 1,600 hp, a considerable boost in power. First flight didn’t take place until 1947.
  • M.520T – Project to further modernize the D.520, never reached the prototype stage.
  • D.520DC – A two seat trainer version developed immediately post-war. DC roughly indicates ‘dual control.’

Operators

  • French Armée de l’Air (French Air Force) – The French Air Force hastily produced and deployed to active squadrons mere months before hostilities broke out between Germany and France. After the conclusion of the Battle of France, and subsequent armistice, the aircraft would continue to serve under the air force the Vichy Regime.
  • Forces Françaises de l’Intérieur (FFI / Free French Forces) – Organized FFI forces operating in recaptured areas of France after Allied breakthroughs in 1944 assembled a few small squadrons and began flying reclaimed D.520s, most notably the “Doret Group,” before being reabsorbed into the formal structure of the revitalized French Army.
  • Regia Aeronautica (Italian Air Force [Axis]) – The Italians managed to acquire several dozen D.520s throughout the course of the war, and pressed them into domestic service defending and intercepting allied bombers over the Italian mainland.
  • Luftwaffe (Nazi Germany) – During Germany’s various incursions into France, several hundred D.520s came under their control, in addition to continuing serial production under German occupation. The Dewoitines that found their way into German service were primarily used as trainers, or were transferred to Axis allies, namely Italy and Bulgaria.
  • Bulgarian Air Force – As Bulgaria was an ally of the Axis powers, upwards of 98 D.520s were transferred to the country’s air force, and used to intercept Allied bomber raids.

Conclusion – The Incarnation of “Trop peu et trop tard”: The D.520 in French Mythos

Since the end of the Second World War, the D.520 has progressively gained a near-mythical status in French military enthusiast circles. The reasons for this are quite easy to identify. The D.520 was the best performing French fighter introduced in large numbers during the Battle of France, and seemingly the only one which posed a credible threat to the Bf 109. However, it arrived too late, and numbers too small to Germany’s advance. In this regard, it was one of a considerable amount of fairly advanced pieces of equipment the French army was close to introducing in 1940, but never could due to the Armistice, similar in this fashion to its fellow Bloch MB.155 and Arsenal VG.33 fighter aircraft, the two Richelieu-class battleships, and the MAS 40 semi-automatic rifle of the French army.

This massive place in French mythos, reinforced by Pierre Le Gloan’s commendable combat record with the type, could be said, however, to have caused some bias to exist in some French analysts, where placing the D.520 as an equal to the Bf 109 has become sort of tradition. While the D.520 was much closer to competing with the German fighter in comparison to the previous MS.406 or MB.152, in some ways, the German fighter could be said to still be a little better performing. It is also questionable whether or not the D.520 could have evolved to become a mainstay fighter for the French air force for the rest of the war, as the Spitfire was for the Royal Air Force and the Bf 109 for the Luftwaffe. In some ways, the VG.33 airframe, which slightly outperformed the D.520, with a previous and weaker version of the same engine, may eventually have provided a better long-term mainstay fighter for France. In any case though, difficult circumstances prevented the VG.33 from ever reaching service, but the D.520 would have the opportunity to live an active service life in a number of air forces, one which saw it in action against both Axis and Allied forces alike.

Dewoitine D.520C-1 specifications

Wingspan 10.18 m /
Length 8.75 m /
Height 2.55 m /
Wing Area 16 m² /
Engine Hispano-Suiza 12Y-45
Power at Critical Altitude 935 hp at 4,200 m
Max RPM 2,400 RRM
Propeller Three-bladed Ratier or Chauvière (3 m diameter)
Empty Weight 2,050 kg /
Maximum Takeoff Weight 2,740 kg /
Wing Load 195 kg/m²
Fuel Capacity 400 liters standard

640 liters with wing fuel tanks

Time to Altitude 4,000 m in 5’13”

6,000 m in 7’57”

8,000 m in 13’24”

Maximum Speed 425 km/h at sea level

535 km/h at 6,750 m

Cruising Speed 400 km/h
Stall Speed 125 km/h
Range Around 900 km with standard fuel load

1,500 km at max fuel fuel load (equipped w/ wing tanks)

Maximum Service Ceiling 11,000 m /
Crew 1 Pilot
Armament 20 mm HS-404 firing through the propeller hub with 60 rounds

4x MAC34M39 machine-guns with 675 rounds per gun in the wings

Number Completed Around 900 (produced 1939-1944)

Gallery

D.520 No.12 Cdt Thibaudet – GC I/3, Cannes-Mandelius, March 1940
D.520 No.90 Sergent Michel Madon who would go on to be credited with 11 confirmed kills during the war – GC I/3, Suippes, France, May 1940
D.520 No.61 Czechoslovak Pilot Cukr Vaclav – GC II/3, Oran-La-Senia Airfield, July 1940
D.520 No.277 flown by “Ace in One Day” Pierre Le Gloan – GC III/6, Prior to Armistice 1940
D.520 No.343 Cdt Moriat – GC II/3, Alep-Nerab Syria, July 1941
Free French D.520 – Not long after the Invasion of Normandy

Credits

  • Written by Marisa Belhote
  • Special Thanks for Contributions to the Italian Section by Arturo Giusti
  • Edited by Henry H., Stan L. and Ed J.
  • Illustrations by Ed Jackson

Sources

Messerschmitt Me 163B Komet

Nazi flag Nazi Germany (1944)
Rocket Powered Fighter – Around 370 Built

The Me 163B in standard camouflage. Note the brightly colored nose. [militaryimages.net]
Following the successful testing of the previous Me 163A series, the Germans began developing a new improved version that was intended for operational use. This would lead to the Me 163B series, which was the first, and last, operational rocket-powered aircraft to be used in active combat. In comparison to its predecessor, the Me 163B offered a number of improvements to its design and shape. By the war’s end, less than 400 aircraft of this type would be built.

History

Work on the second series of the Me 163, which would be built in greater numbers than the experimental A-series, began at the start of September 1941. In comparison to the predecessor, the B-version had a number of modifications. The most obvious change was the completely redesigned fuselage, which was larger and had an overall more aerodynamic shape. Its armament was installed in the wing roots, the engine was replaced with an improved version, and the pilot cockpit was enlarged.

The differences between the Me 163A (on the left) and the main production version are clearly evident here. [acesflyhigh.wordpress.com]

Initial plans for this aircraft were quite ambitious, as Messerschmitt had predicted that the production of four operational prototype aircraft with additional airframes should commence in October 1941. Once the first few prototypes were completed, a small series of 66 aircraft were to follow. The actual responsibility of building these was given to Messerschmitt production plants at Regensburg with assembly at Obertraubling. It was estimated by RLM (Reichsluftfahrtministerium – Ministry of Aviation) officials that, after the first batch of 70 aircraft was built, it would take some 7 months to actually begin mass production of fully operational aircraft.

One of the first few Me 163B prototypes built. [luftwaffephotos.com]
As was the case with many German wartime projects, it suffered from delays due to a lack of resources. The work on the initial group of prototypes started only at the end of 1941. Once again, further delays due to the slow delivery of engines postponed production until March of 1942. At this stage, the Germans were replacing the R II 209 rocket engines with the modified RII 211. The new engine used different types of fuel tanks which necessitated the redesign of the fuselage interior. This engine used a combination of T-Stoff and C-Stoff (a mixture of hydrazine hydrate, water, and methanol). As the construction of the Me 163B V1 prototype was approaching completion, it was proposed to switch to the older R II 203 engine to save development time, but this modification was not carried out. The development of the rocket engines was very slow and plagued with many setbacks, especially the limited production of fuel, which eventually led to huge delays in the Me 163 production. Finally, for the Me 163 production aircraft, the improved HWK-509 engine was chosen.

In May 1942, Me 163 B-0 V1 (KE+SX) was completed, minus the engine, and was tested as an unpowered glider. By 1943, it was obvious that Messerschmitt alone could not cope with the wartime demands, so RLM officials decided to bring aboard another aircraft manufacturer. They chose Klemm’s Stuttgart-Boeblingen factory, with a monthly goal of some 30 Me 163 aircraft. Klemm was also tasked with providing additional workers for Messerschmitt. Delays in delivering essential parts, such as weapons, caused setbacks in the Klemm Me 163 production.

Despite the problems with the Me 163 production, a small number of available aircraft were allocated to the Erprobungkommando (EKdo) 16 unit from April 1942 onward.

First Flights by EKdo 16

Once the first prototype was available, it was flight-tested as a glider by Heini Dittmar in late June, or May of 1942, depending on the source. Heini Dittmar had plenty of experience as a test pilot flying the Me 163A aircraft. The BV1 prototype would be, from this point on, mainly used as a training glider aircraft. From this point forward all aircraft built would be transported to Bad Zwischenahn near Oldenburg. Once there, they would be flight-tested by a number of pilots under the command of Karl Voy from EKdo16. This unit, which was formed in April of 1942, had the primary function of testing and evaluating the newly built Me 163 and helping in the development and improvement of its overall design. Another purpose that this unit had to fulfill was the training of new pilots for the Me 163.

An interesting episode in EKdo 16’s history is connected to the well-known German test pilot Hanna Reitsch. After a number of attempts to get permission to flight test the Me 163, she was finally allowed to do so at the end of 1942. Shortly after she took off, the jettisonable takeoff dolly refused to successfully detach from the aircraft, preventing it from using the landing skid. She managed to land the aircraft but was badly wounded and was placed in a hospital for some time. She later requested permission to fly the Me 163 again, but was explicitly rejected and was forbidden from flying it.

In early 1943, this unit was also tasked with testing jet-powered aircraft that were currently in development. These included the Me 262 and the He 280. EKdo 16 began receiving the first operational Me 163Bs only in July, or February of 1943. Due to extensive Allied Air Force activity near EKdo 16’s base of operation, the unit began the process of relocating its aircraft to Anklam. By this time, the unit had some 7 Me 163A and 1 of the B version. Due to poor ground conditions for Me 163 operations, the aircraft was relocated back to Bad Zwischenahn in late August. The delays with the construction of auxiliary support buildings on this airfield meant that crew training could not begin until October 1943. These initial training flights were carried out using two-seater gliders. Due to a lack of C-Stoff fuel, another series of delays impacted progress on training. In November, the Me 163As were used for crew training. In November and later in December, two aircraft were lost in accidents with the loss of life of both pilots.

In the following months, due to a number of factors like slow production, bad weather, and Allied activity, the Me 163 training program progressed at a slow pace. By May 1944, only a small group of fewer than 50 pilots had a chance to fly either the powered or towed versions of the Me 163. Once these were successfully tested, they would be then allocated to the 1./J.G. 400. unit.

The first combat action of the Me 163 was conducted on 14th May 1944, piloted by Major Spate. Amusingly, just prior to the first flight, his Me 163 BV 41 (PK-QL) aircraft was painted in red. This was done by the unit mechanics, who wanted with this small gesture to bring good luck to their pilots. Seeing no harm in it, Major Spate gave instruction that his aircraft be fully fueled and armed. During his flight, he attempted twice to attack Allied bombers but failed to properly engage them. It seems the red paint did not help with the luck.

During May, a number of unsuccessful combat flights with the Me 163 were undertaken. At the end of May, the airfield at Bad Zwischenahn was heavily bombed. During this attack, several Me 163s were damaged. This attack left the airfield at Bad Zwischenahn unusable for some time. To continue the training of pilots, the whole operation was temporarily moved to Brieg on the Oder. As this airfield lacked any proper workshops, the dismantled aircraft could not be assembled again and, for this reason, no test flights were ever carried out from Brieg.

Interestingly, on the 12th and 13th June 1944, three Me 163s from the EKdo 16 were demonstrated to the Japanese and Italian military delegations. As, at that time, EKdo 16 could not provide a fully operational Me 163, these were instead taken from 1./J.G. 400.

On 15th June 1944, the unit was once again back to Bad Zwischenahn. At their disposal, there were 2 prototypes, 7 gliders and 11 fully operational Me 163 aircraft. A few days later, another accident occurred when the towing aircraft lost power to one of its engines. The towed Me 163 was released at some 50 meters of altitude and the pilot was forced to land at a nearby lake. While the aircraft was heavily damaged, the pilot managed to survive.

In July 1944, a second auxiliary unit (Erganzumgsstaffel) was formed. It was also subordinated to the 1./J.G. 400. It had 6 Me 163s, of which only one was equipped with a rocket engine. It was intended to supplement the training of pilots for 1./J.G. 400.

In mid-August 1944, the airfield was once again attacked by Allied bombers. This caused further delays in training operations, until August 23rd. On that day, another accident led to the death of a pilot and the loss of yet another aircraft. Not wanting to waste the parts of the destroyed Me 163, these were collected and then sent to the training school at Fassberg.

At the start of September, Luftwaffe Generalmajor Adolf Galland told EKdo 16’s Commander Hauptmann Thaler, that the unit was to be disbanded and all personnel and equipment were to be relocated to Brandis. While the commanders of EKdo 16 were against such a decision, there was little they could do and, by the end of September, the unit was on its way to Brandis.

An Me 163 from EKdo 16. While some combat flights were undertaken, the primary purpose of this unit was to provide necessary pilot training. [aviationshoppe.com]

Technical Characteristics

The Me 163 was a high-speed, rocket-powered, swept-wing tailless aircraft. Its fuselage was constructed of metal, while the wings were wood. The fuselage could be divided into three sections, the cockpit, the central fuel tanks, and the rear engine compartment. In order to help the ground crew with repairs, the fuselage was specially designed to contain a large number of removable panels. Thanks to this, the replacement of damaged parts or even the whole engine could be done relatively quickly.

The wings were quite simple in design, consisting of two spars covered in 8 mm thick fabric. The Me 163 wings were swept to the rear at a 23.3° angle. At the wing’s trailing edges, ailerons were placed, which the pilot used for pitch and roll. For landings, large hydraulically operated flaps were added on the wings.

In order for the pilot to enter the cockpit, a ladder was placed on the left side of the aircraft. While the cockpit was not pressurized, it could be jettisoned to help the pilot escape the aircraft in case of emergency. Being unpressurized actually placed time limits for how long the pilot could endure without losing consciousness at altitude and during high-speed maneuvers. For this reason, the pilot had to endure altitude chamber training and had a specially designed diet. Despite attempts to improve visibility compared to the previous version, the Me 163B suffered from poor visibility, especially to the rear and in front of the aircraft’s nose.

In order to enter his flight position, the pilot used a small ladder placed on the left side of the aircraft. [acesflyinghigh.wordpress.com]
Close-up view of the Me 163 cockpit and instruments. [luftwaffephotos.com]
The Me 163 was equipped with various onboard equipment, including a FuG 16 ZE radio transmitter and receiver. In addition, a FuG 25 IFF (identification friend or foe) transmitter and receiver was installed. Given its small size and limited overall weight, the onboard batteries had a limited capacity. In order to provide the necessary power, the Germans simply added a small windmill generator which was placed on the nose of the fuselage.

During its development, the Me 163B was tested with a series of different rocket engines. Ultimately, for the main production version, the HWK (Helmuth Walter Kiel) 109-509A rocket engine was chosen. This had a thrust power ranging from 100 kg (220 lbs) to 1,500 kg (3,300 lbs) or 1,700 kg (3,750 lbs), depending on the source.

The Me 163 initially used a fuel mixture of the T and Z-Stoff. T-Stoff consisted of a mix of hydrogen peroxide with oxyquinoline or phosphate. Z-Stoff was an aqueous solution of calcium permanganate. Z-Stoff would later be replaced with C-Stoff, which was a mix of methyl alcohol, hydrazine hydrate, and water. T-Stoff was stored in one main and two smaller auxiliary tanks. The smaller tanks were placed on both sides of the cockpit. The C-Stoff fuel tanks were placed in the Me 163’s wings. In order to help circulate the fuel, two centrifugal pumps were placed inside the Me 163.

These chemicals were extremely flammable and dangerous to handle and thus required safety procedures to be used properly. Before each flight, the fuel tanks had to be thoroughly washed with water. During refueling, the ground and the aircraft had to be sprayed with large amounts of water. If the safety procedures were not followed, there was a great risk of explosion, which happened on occasion. Due to the volatile nature of the fuel, any harsh landing with fuel still onboard offered a great chance of explosion as well, which led to a number of pilots being lost. Being highly corrosive and deadly to the touch, the maintenance crews and pilots had to wear specially designed protective clothing and gloves. Preserved photographs seem to indicate that these precautions were not always strictly adhered to. Given that the Me 163 operated in late 1944 were shortages of all kinds of equipment and materials were common, this should not come as a surprise. Still, handling the Me 163 fuel without this kind of protection was highly dangerous for the ground maintenance crews.

This Me 163 is in the process of being refueled. [acesflyinghigh.wordpress.com]
The fuel load consisted of 1040 liters (229 gallons) of T-Stoff and 492 liters of C-Stoff. The Me 163 was notorious for having only a limited powered flight endurance of 7 minutes and 30 seconds before its fuel reserve was spent. The actual flight could be much longer, however, since at sufficient altitude, the pilot could switch off the engine, and reactivate it as needed. After all rocket fuel had been spent, the pilot would then use the Me 163 as a glider to fly back to its base, or to any nearby German airfield.

The initial armament consisted of two 20 mm MG 151/20 cannons, which were positioned in the wing roots. To increase the firepower these would be replaced with the stronger 30 mm MK 108 cannons. The Me 163B-0 series was armed with the weaker 20mm cannon while the Me 163 B-1 with the stronger 30mm cannon. While the Mk 108 had sufficient firepower to outright destroy or heavily damage enemy aircraft, it was plagued with low velocity. This combined with the extraordinary speed of the Me 163 made engaging targets difficult. For this reason, the Me 163 was tested with some experimental weapon systems. These include the 5.5 cm R4M air-to-air rocket, and the more revolutionary SG 500 Jagdfaust. This weapon consisted of five rockets usually placed under each wing, but on the Me 163 it was actually mounted vertically in the wings. It was provided with an optical sensor that activated its weapon load once it detected shadow, in theory, a shadow of an enemy plane. This was an automated weapon firing mechanism capable of friendly fire if not managed properly. But this situation would be rare given the fact that Me 163 was a short-range and unique interceptor that operated on its own without support from other aircraft.

The Me 163 was armed initially with two MG 151 and later with MK 108 cannons which were placed in the wing roots. The left-wing cannon muzzle brake is visible in this picture. The pilot in this picture is Heini Dittmar was a vital test pilot for the whole Me 163 project. [acesflyinghigh.wordpress.com]
The Me 163 utilized an auxiliary landing gear unit. This was mainly done to reduce the overall weight of the aircraft. Take-offs and landings were divided into two phases. For take-off, the Me 163 sat on a simple two-wheel dolly unit. Once at sufficient altitude the dolly was jettisoned from the bottom of the aircraft. On occasion, there were accidents involving this system, when, for example, the dolly refused to release from the aircraft, or even worse, it could bounce off the ground and strike the aircraft from below. Therefore the Germans worked on developing safer types of dollies. On landing, the Me 163 were to use a simple retractable landing skid, placed beneath the fuselage. In addition, to the rear of the aircraft, a small steerable tail wheel was added to help during take-off and landing.

Close-up view of the Me 163 landing skid. [Wiki]
The rear wheel was completely steerable and was added to help during take-off and landing. [warbirdphotographs.com]
 

Once at a sufficient height, the two-wheel dolly would jettison from the aircraft (in the left corner). While in theory, this should work without any issue, in some cases the dolly would simply bounce off the ground and hit the aircraft from below potentially causing damage to it. [luftwaffephotos.com]
While this takeoff and landing system offered the desired reduction in weight, it was not without its problems. Besides the issues previously mentioned, after a successful landing, the Me 163 was immobile and vulnerable to possible enemy attacks. To move it across the airfield the Germans designed and built a small specialized aircraft tug, called the Scheuchschlepper, especially for this task.

The Scheuchschlepper is specially designed to either tow or lift the Me 163 aircraft. [warbirdphotographs.com]
The Scheuchschlepper essentially fulfilled two roles. Initially, in the three-wheel configuration, it was to tow the Me 163 along the airfield, using its own dolly, to a designated takeoff position on the airfield (upper picture). After the Me 163 returned from a sortie, the Scheuchschlepper rear wheel would be replaced with a tracked platform which supported a cradle that fully supported the entire aircraft at its wing roots, to move the Me 163 for refueling and to be refitted on a takeoff dolly for the next flight. [wiki]

Operational Combat Use

The first operational unit that was to be equipped with the Me 163 was the Staffel of Jagdgeschwader 20./JG 1 located at Bad Zwischenahn. According to initial plans, this unit was to be formed at least by the end of 1943 or in early 1944 depending on the sources. In its inventory, there were some 12 fully operational Me 163 available. In addition, the Germans planned for the Me 163 to be positioned at a series of auxiliary airfields along Allied bomber routes. These would be fully equipped with spare parts, ammunition, and fuel, and positioned close to each other. This way, after an attack run, the Me 163 pilots could simply choose on which airfield to land, knowing that they could resupply without any problems.

But in reality, it took a few more months before the unit was actually officially formed at the start of March 1944. The development of a network of supporting airfields for the Me 163 was also never completed. The unit was by that time being renamed to Jagdgeschwader 1./JG 400 and stationed at Deelen. The commander of the unit was Oberleunant Rober Olejnik. They were relocated to Wittmundhafen as the airfield at Deelen proved unfit for the Me 163 aircraft’s operation.

The unit received its first operational Me 163 on the 10th of March, and seven more were to arrive by late April 1944. Concurrently, pilots were beginning to arrive from the EKdo 16 training unit. More test flights were carried out until mid-March 1944 when they had to be temporarily stopped. The reason for this was the lack of sufficient water supply which was essential for flushing the Me 163 fuel tanks in order to avoid any accidental explosion. To resolve this issue the unit personnel began drilling wells to collect water.

1./JG 400 was at this stage prohibited from making combat flights in order to avoid the attention of the Allies. However, the unit was permitted to conduct live firing trials during flights in order to test the Me 163 weapons systems. While generally successful, during sharp maneuvers at a speed of some 800 km/h, the ammunition belts proved prone to malfunction. While Olejnik suggested using a drum magazine, which was even tested successfully, his idea would not be adopted. On the 21st of April Olejnik had an accident during a forced landing where he spent some time in hospital thereafter.

In April and May, 1./JG 400 took delivery of a group of 10 aircraft, but one had to be returned to Klemm for modifications. That particular aircraft would be destroyed in an Allied bombing raid on Klemm. These were still prototype aircraft of the B pre-production version. The first Me 163B-0 series aircraft began to arrive from May 1944. At this time the Luftwaffe officials were determined to introduce the Me 163 to service. For this reason, the work on testing and experimenting with the Me 163 was stopped in favor of increasing the overall production of the Me 163 B-1.

With the expected increase in production, another unit, 2./J.G.400, was to be formed in May 1944. It was initially to be involved with crucial crew training. At that time, the size of both units was to be increased to 14 instead of 12 operational aircraft.

In July 1944, 1./JG 400 received permission to make combat flights. The Me 163 were then used in several failed attempts to intercept the Allied reconnaissance aircraft that made frequent flights over the base. At the same time, 1./JG 400 and other available Me 163 were being relocated to new positions at Brandis. The original plans to build numerous connected airfields were abandoned in favor of concentrating all available Me 163 in a few selected airfields. For this reason, Brandis would become the main key point for the Me 163 combat operations. It is from there that the Me 163s attempted to intercept a huge Allied air formation of some 766 bombers, supported with over 14 groups of cover fighters. The Me 163 did not engage the Allies probably due to the small number of available aircraft and the heavy fighter cover. By the end of July, the 1./JG 400 had only four operational aircraft out of 16 available.

In mid-August, Me 163s from this unit attacked an Allied B-17 bomber formation. While evading the fighter cover, they managed to heavily damage at least one bomber, killing two crew members. On the 16th of August, five Me 163 attacked a group of B-17s, and even managed to shoot down two of the bombers. The Germans lost one Me 163 during this engagement being hit by an Allied P-51. On the 24th of August, eight Me 163 managed to shoot down three more bombers while successfully evading enemy fighter cover.

While this aircraft managed to fly back to Allied Air Bases in England, the damage inflicted by the Me 163 cannons is evident here. The rear gunner position was completely destroyed while the right tail unit was heavily damaged. [. Ransom and H.H. Cammann Jagdgeschwader 400]
On the 8th of September, the Me 163 were officially taken into service. Given the previous success, of destroying 5 enemy bombers with a limited number of available Me 163, attempts were made to increase the number of squadrons with 20 aircraft. This was never achieved, as the Allies destroyed the vital C-Stoff fuel production facility at Kiel in August. On the 11th of September, a single Me 163 attacked and destroyed a lone B-17.

During these initial combat engagements with the Allied bombers, German pilots noticed that the Me 163s armament had a huge flaw. The weapons were difficult to use with the standard attack tactics of the aircraft. This involved getting the Me 163 high above the Allied bombers and then plunging down at them with a dive speed of 885-930 km/h (550-580 mph). Due to its main cannon’s low velocity, and in order to avoid collision with the target, the pilot had only a few seconds available to engage the enemy. This meant that only the highly experienced Me 163 pilot had a chance of hitting the enemy aircraft. The Me 163 also had another flaw, as it could be only used when the weather was clear.

At the end of September 1944, II./JG400 was formed, under the command of Lieutenant Peter Gerth (3/JG 400) and Oberleutnant Franz Woidich (4/JG 400). These units were renamed in November or December 1944 to 5. and 6./JG 400. During this time the 7/JG 400 was also formed, which was stationed at Stettin-Altdamm. In late 1944 II./JG400 was repositioned at Stargard. Few sorties were carried out mostly due to lack of fuel. In November 1944 a Me 163 engaged a British Mosquito, damaging it and forcing its crew to abandon the aircraft.

An Me 163B is engaging Allied B-17 bombers. The Me 163, despite its small number, proved to be a shock to the Allies pilots. Given that they could do little against it when the Me 163 was in its dive attack. [acesflyinghigh.wordpress.com]
Bad weather, lack of fuel and the rapid Allied advance on the West and East temporarily stopped all Me 163 combat operations. Combat operations began again in March of 1945. For example on the 16th March, an Me 163 managed to damage another Mosquito on a reconnaissance mission. While the Mosquito pilot managed to fly back to France, he was forced to crash land. A quite interesting Me 163 air victory was achieved on the 10th April 1945 while piloted by Leutnant Fritz Kelb. This aircraft was equipped with the experimental SG 500 Jagdfaust and managed to shoot down a British Lancaster bomber.

In late April I/.J.G.400 would be disbanded and its remaining few operational Me 163 were allocated to the J.G 7. The former I/.J.G.400 commander Wolfgang Spate, flying one of the remaining operational Me 163, managed to destroy 5 additional Allied bombers by the end of the war. The remaining ground personnel from the I/.J.G.400 were dispatched to the East to fight as infantry in Bavaria. There, they allegedly managed to destroy a Soviet tank using a MK 108 cannon removed from an Me 163, which was placed on makeshift undercarriage wheels, also taken from a Me 163. Given the chaotic state of Germany in 1945, it’s conceivable that the crew operating this gun may have found a way to make it work.

After the War

In May 1945 the Allied forces were rapidly advancing into Germany, capturing many airfields in the process. The crews of the Me 163 were often instructed to destroy their own aircraft to prevent them from falling into the enemy’s hands, but despite this, the Allies managed to capture a number of intact Me 163. This was the case of the II./J.G.400, which surrendered its 48 aircraft to the Allies on the 8th of MAy 1945. Of these, some 25 were transported back to the UK to be properly examined. The Americans also managed to capture a number of Me 163 in various working conditions across occupied Germany. The French Air Force received at least 4 Me 163 from the British after the war. The Soviets were not idle either as they also managed to acquire unknown numbers of the Me 163 including the rare two-seater trainer version Me 163S.

One of the 25 aircraft that were shipped to the UK by the English after the war. [acesflyinghigh.wordpress.com]

Me-163C

In an attempt to increase the Me 163’s performance, Junkers cooperated with Dr. Lippisch. This resulted in the development of a modified Me 163 (based on the BV6 prototype) which was slightly larger, had greater fuel capacity and had two engines. In theory, during take-off, both engines would be activated until a certain altitude was reached. This project would eventually evolve into Me 163C. This aircraft was to have a redesigned fuselage and cockpit. It was to be powered by HWK 109-509A-2 and HWK 509C engines. By the end of the war, only a few incomplete airframes were built.

The Me 163B V6 was tested with two engine configurations It was to serve as the basis for the planned Me 163C version which was never completed, aside from a few airframes. [E. T. Maloney and U. Feist Messerschmitt Me 163]
An Me 163C illustration of how it may have looked given that only few uncompleted airframes were built. [walterwerke.co.uk]

Japanese Me-163B

In 1944, on Adolf Hitler’s instructions, a number of previously secret projects were to be shared with the Japanese. For this reason, several submarines were to transport parts of a disassembled Me 163B to Japan. While the one carrying the aircraft parts was sunk, the others that were carrying technical manuals managed to reach the German ally. Based on these, the Japanese managed to build a slightly modified copy of the Me 163. It was known in Japan as J8M1 Shuri (Rigorous Sword). During the first test flight, there was an accident in which the prototype was lost.

During negotiations between Japanese and German military officials, it was agreed to hand over to Japan a production license for many weapons including the Me 163 and Me 262. It was named Mitsubishi Ki-200, for the army, and J8M1 for the navy. The first Me 163B flew in July 1945 but was lost in an accident. Several more were built but the end of the war led to the end of the project.

While the Japanese experimented with their own copy of the Me 163, they did not manage to put it into production. [Wiki]

Production

The production of Me 163 was initially allocated to the Messerschmitt Regensburg factory. As it was overburdened with other projects, it would then be allocated to a much smaller Klemm factory where less than 60 aircraft were built in total. Some sources also mentioned that the production was carried out at the Dornier factory in Oberpfaffenhofen and the Bachmann von Blumenthal factory in Fürth. On the 1st of September 1944, the production of the Me 163 was officially handed over to Junkers. To avoid concentrating the production in one location, given the Allied bombing campaign, Junkers dispersed it across numerous smaller companies. Each of these was tasked with the delivery and production of parts before being finally assembled at Brandenburg-Briest. This, in theory, would increase the overall production and avoid potentially being targeted by Allied bombers. In reality, this backfired, as it caused huge confusion and chaos with the delivery of parts, and poor quality in production. Junkers managed to produce around 299 aircraft of this type by the end of the war.

The question of how many Me 163B were produced during the war is difficult to pinpoint precisely. The sources give different numbers, for example, most state around 400 of all models, of which some 370 were estimated to be of B-version, were built by the war’s end.

  • Me 163B-0 – Pre-production aircraft
  • Me 163B-1 – Main production aircraft
  • Me 163C – Experimental twin-engine modifications of the Me 163B aircraft but only few incomplete airframes were ever built

Operators

  • Germany – Built less than 400 aircraft of which only a smaller number were ever used in combat
  • Japan – Built a small number of slightly modified Me 163B by the end of the war.
  • Soviet Union – Several Me 163B and one Me 163S, captured, were used for many different tests after the war. The results of these tests will lead to the development and creation of several different projects (The Lavochkin I-162 and Mikoyan-Gurevich I-270).
  • UK – Managed to capture some 48 or so Me 163 aircraft of which 25 were sent to the UK for testing and evaluation.
  • France – Received four aircraft from the British after the war.
  • USA – Acquired an unknown number of Me 163 at the war’s end.
  • Australia and Canada – Both received one aircraft from the British after the war.

Surviving Aircraft

Today at least several Me 163 are known to still exist. One could be found in the Australian War Memorial in Canberra, and one in the Canada Aviation and Space Museum in Ottawa. Two are located in German museums: Luftwaffenmuseum at Berlin-Gatow and Deutsches Museum in Munich. Few more are in the USA Flying Heritage Collection, National Museum of the USAF, and Smithsonian National Air and Space Museums. And in the UK, RAF, Science and National Museum of Flight. The one captured by the Soviets existence is currently unclear.

Luftwaffe Museum at Berlin-Gatow [acesflyinghigh.wordpress.com]

Conclusion

The Me 163 was designed to be light and relatively cheap to build. This was certainly a strength if we take into account the huge shortage of resources and materials that the Germans endured during the later stages of the war. It also used special fuel that was specially designed for it, and thus there was no need for allocating the vital German fuel reserves to it.

With the two MK 108 cannons, the Me 163 was formidably armed given its small size. Just a few rounds of this cannon was enough to destroy or heavily damage an enemy target. Given its phenomenal speed during dive attack at the enemy formation, the Me 163 was essentially immune to enemy fighter cover and was unable to do much against it. That is until it ran out of fuel, at that point it was completely helpless and could only glide back to base.

On the other hand, it was overshadowed by a number of critical faults that were never corrected. For example, while the Me 163 was cheap, due to many reasons it was never produced in any sufficient numbers to cause any serious threat to the Allies. While the number of some 400 aircraft built seems significant, in reality only a dozen or so aircraft were ever used at any given time in combat. Most were used for training, either as gliders, or with an operational engine. Not all built aircraft would be delivered to the operational units, given the great confusion and chaos that the Germans were surrounded with from 1944 on. The fuel could never be produced in sufficient quantities. The problem with fuel was even complicated by the increase in production of the Me 163. Because of this the Germans simply had to reduce the number of aircraft that they used for combat, as there wasn’t enough fuel for all of them. The volatile nature of its fuel, occasionally lead to accidents and explosions, losing aircraft in the process, but more importantly the vital pilots. While its speed was great, its maximum burn time for the engine was only slightly longer than 7 minutes, however this capability could be stretched by the pilot’s ability to switch the engine on and off throughout the flight. Once the engine consumed all the fuel reserves, the aircraft essentially became a simple glider that was vulnerable to enemy fighter cover.

In the final analysis, the Me 163 theoretically possessed great potential for a rocket-powered aircraft. In reality, due to many delays, lack of unity in German aviation circles, and problems with its design and production, the Me 163 never managed to fulfill the role that its designer had intended for it. Its achilles heel was its dangerous and volatile fuel from which a number of planes and pilot lives were lost. Probably its greatest contribution was that it provided a good experimental platform for flight tests at transonic speeds. But due to its unusual design the Me 163 certainly deserves a great place in the history of the development of aviation.

Me 163B Specifications

Wingspans 30 ft 7 in / 9.32 m
Length 19 ft 2 in / 5.84 m
Height 9 ft 1 in / 2.77 m
Wing Area 199.4 ft² / 18.5 m²
Engine One HWL 509A rocket engine
Empty Weight 4,200 lbs / 1,900 kg
Maximum Takeoff Weight 9.060 lbs / 4.110 kg
Fuel Capacity 1,530 liters / 400 US gallons
Maximum Speed 600 mph / 960 km/h
Engine endurance 7 minutes and 30 seconds
Maximum Service Ceiling 39,700 ft / 12,100 m
Crew One pilot
Armament
  • Two 20 mmMG 151
  • Or two 30 mm MK108 cannons

Gallery

Me 163BV 41 PK+QL 1./J.G. 400. This aircraft, painted in red and piloted by Major Wolfgang Spate, flew its first combat mission on May 14th, 1944.
Me 163B V45 PK+QP Erpobungskommando 16 at Bad Zwischenahn, May 1944
Me 163B V52 GH+UI ‘Yellow 1’ 7./JG 400, Stettin-Altdamm, October 1944
Me 163B
Me 163B

Credits

  • Written by Marko P.
  • Edited by Henry H. & Ed Jackson
  • Illustrated by Carpaticus

SourcesMe

  • D. Nešić (2008) Naoružanje Drugog Svetsko Rata-Nemcaka. Beograd.
  • W. Spate and R. P. Bateson (1971) Messerschmitt Me 163 Komet , Profile Publications
  • M. Ziegler (1990) Messerschmitt Me 163 Komet, Schiffer Publishing
  • M. Emmerling and J. Dressel (1992) Messerschmitt Me 163 “Komet” Vol.II, Schiffer Military History
  • E. T. Maloney and U. Feist (1968) Messerschmitt Me 163, Fallbrook
  • S. Ransom and H.H. Cammann (2010) Jagdgeschwader 400, Osprey publishing.
  • D. Donald (1990) German aircraft of the WWII, Brown Packaging books ltd
  • D. Monday (2006) The Hamlyn Concise Guide To Axis Aircraft OF World War II, Bounty Books.
  • D. SHarp (2015) Luftwaffe secret jets of the Third Reich, Mortons Media Group
  • H. Morgan and J. Weal (1998) German Jet Aces of the World War 2 , Osprey Aerospace

Belyayev DB-LK

USSR flag USSR (1938-1940)
Experimental Long-Range Bomber – 1 Prototype Built

The Belyayev DB-LK [airwar.ru]
In the late thirties and early forties, the Soviet aviation industry had developed and tested a variety of aircraft design concepts, some quite peculiar. While generally unknown around the world, a number of these strange aircraft would represent a serious departure from anything resembling their contemporaries. Such is the case with Victor Nikolayevich Belyayev’s DB-LK experimental long-range bomber.

History

Victor Nikolayevich Belyayev, March 1896 – July 1953, began working for the Department of the Marine Experimental Aircraft Construction, OMOS, in 1925, where he gained his first experience in aircraft design. In the following years, he worked for the Central Aerohydrodynamic Institute, TsAGl, and Tupolev. During this time, he became an advocate for tailless aircraft designs. He also argued that the so-called “batwing”  or “butterfly”, offered better performance, due to their reduced drag and better stability, than regular wing designs.

The “batwing” design possessed a slightly forward-swept wing with back curved tips. Belyayev managed to construct a glider, designated BP-2, which was equipped with this kind of wing design in 1933, on which he tested this concept. During its test flight, it was successfully towed in the air from Crimea to Moscow, where it proved to have good stability and control during flight.

The BP-2 glider in flight. [airwar.ru]
The next year, Belyayev participated in the competition for a new Soviet military transport plane design. His design was unusual, as it consisted of a large wing and two nacelles,  powered by Tumanskii M-87B 950 hp (708 kW) engines. His design was not approved nor did he build a working prototype. However, four years later, he would reuse this project and adapt it for the role of a long-range bomber. In 1938, he designed the DB-LK long-range flying wing bomber, which the TsAGl approved and ordered the construction of a fully operational prototype. The prototype was built the following year by factory No.156 and by November 1939 it was ready for testing.

Technical Characteristics

The DB-LK had an unusual overall design with no classical fuselage. Instead, the crew, armament, and other equipment were located in the two extended engine nacelles that ended in glazed tail cones (gondolas), somewhat similar to the later German Fw 189. The two extended engine nacelles were, technically speaking, the plane’s fuselage. The semi-monocoque fuselages were constructed by using a combination of metal frames and longerons covered with a duralumin sheet. The DB-LK was designed in this unusual configuration in the hope of reducing the overall drag and weight and thus increasing its speed and range.

The DB-LK’s wings had a unique design, where beside the “batwings” there was an additional center wing section between the two fuselages. Also, the wings were slightly swept to the front with back curved tips. The wings consisted of an airframe covered with light metal stressed-skin. The outer wings had a Gottingen 387 profile, while the center section had a CAHI (TsAGI) MV-6bis profile. The wing edges were curved at an angle of -5° 42′.

A side view of the DB-LK. The strange wing design can be seen. [elpoderdelasgalaxias.wordpress.com]
The rear tail was located on the middle section wing between the two fuselages. The tail consists of one fin and a large 20 ft2 (1.9 m2) rudder. Above the rudder, a smaller tailplane with two, one on each side, large elevators was placed.

A rear view where the large tail and the left glazed rear cone can be seen. [airwar.ru]
One Tumansky M-87B 950 hp (708 kW) 14-cylinder radial engine was installed at the front of both nacelles. For these engines, three-bladed propellers with variable pitch were used. It was planned to upgrade these two with much stronger 1,100 hp (820 kW) M-88 engines, or even the 1.700 hp M-71, but this was never implemented. The fuel was stored in the wing and fuselage tanks, with a total fuel load of 3.444 l.

The landing gear retracted rearwards, with one wheel (900 x 300 mm) in each fuselage. During later testing, the landing gear design was changed with a forward retractable one. This whole landing gear system was operated hydraulically. There was a small fixed rear wheel (450 x 150 mm) located at the bottom of the tail unit.

The DB-LK was to be operated by a crew of four: the pilot, navigator, and the two rear gunners. The pilot position was in the left cockpit and the navigator in the right. The gunners were positioned in both rear glazed cones. One of the two gunners was also the radio operator. The crews entered their positions through roof hatch doors. The two glazed cones could be mechanically rotated 360° by using a small electric engine located at the fuselage top, but the sources do not specify why this was done.

Inside the pilot cockpit [авиару.рф]
The interior of one of the two fuselages. In the picture on the right, the rear machine gun mount can be seen. On the left, the radio and the mechanism that rotated the whole glazed cone can be seen. [авиару.рф]
Both rear glazed tail cones had a recess where a twin  7.62 mm (.30 caliber) ShKAS machine gun mount was installed. These machine guns had a -10 to +10 field of fire in all directions.  Besides these four machine guns, there were two additional ones forward mounted in the leading edge of the center section. These two machine guns were operated by the pilot. In total, around 4,500 rounds of ammunition were provided for these machine guns. The bomb bays were located behind the landing gear doors in each of the two nacelles.

Depending on the sources, the load capacity of the bomb carried is different. The authors Yefim G. and Dimitri K. note that the bomb load was 1000 kg (2,200 lb) with another 1000 kg that could be carried on external racks. According to Bill G., the capacity of each bomb bay (in each fuselage) was one 1000 kg (2.200 lb), two 500 kg (1.100 lb), or smaller bombs with a total of 1000 kg (2.200 lb) weight.

 

Both front and rear views of the DB-LK’s unusual design. [авиару.рф]

Flight Tests

While being completed in November 1939, the first extensive flight test would only begin the following year. This was due to the unwillingness of the test pilot to fly this plane. He did not believe that it was safe to fly due to its unorthodox design. During this time, the plane received the nickname “Kурица” (chicken).

In order to move the entire project testing through this roadblock, the Soviet Direction of the Air Force Scientific test institute, GK Nil WS, appointed M. Nyuikhtikov as the main test pilot, supported by aircraft engineer and test pilot T. T. Samarin and N. I. Shaurov. Under the new leadership, the tests were carried out in the spring of 1940. During the new leadership, the DB-LK was extensively tested in over 100 flights.

During these flights, the pilots managed to reach speeds of 245 mph (395 km/h) at sea level and 300 mph (490 km/h) at an altitude of 16,400 ft (5,000 m). The DB-LK needed a 2,030 ft (620 m) long airfield for landing and taking off. However, the  DB-LK was never truly trialed with a fully loaded payload. The numbers presented above would have likely been different with a full payload of equipment.

The test pilot Nyuikhtikov, after flying on the DB-LK, pointed out some issues with the plane’s design. The main problems were the inadequate overall flight-control system, poor visibility for the pilot and the navigator, especially on the ground. He also noted the poor construction of the landing gear. These reports were examined by the Nil WS Commission led by A. I. Filin. They agreed that the control system should be improved, but Filin had a positive opinion on the landing gear construction. Ironically, during a test flight, where Filin was the pilot, there was a landing gear malfunction during the landing when one of the front wheels broke free, after a possible collision with a treetop. The aircraft was only lightly damaged and the testing continued, but this led to a change in the landing gear design.

There were also other problems mentioned during the tests, like uncomfortable cockpits, low-level of fire protection, structural problems, a limited firing arc of the rear-mounted defense machineguns, and the tendency for the crew compartments to be filled with exhaust fumes from the engines. To solve these issues, there were plans for the DB-LK improvements, with stronger engines, wings, and various other modifications, to be completed by late 1940 but they were probably never implemented.

Rearview of the accident. [авиару.рф]

Conclusion

Despite plans for more testing and improvements, unfortunately for the DB-LK design team, they never got a chance to do so. In late 1940, the Nil WS Commission gave orders for the cancellation of the DB-LK program. The main reason for this was the decision for the production of the Il-4 as the main Soviet long-range bomber.

 

Belyayev DB-LK specifications
Wingspan 70 ft 10 in / 21.6 m
Length 32 ft  1 in /  9.8 m
Wing Area 612 ft² / 65.9 m²
Engine 2x Tumanskii M-87B 950 hp (708 kW) 14 cylinder radial engines
Empty Weight 13,230 lbs / 6,000 kg
Maximum Takeoff Weight 23,530 lbs / 10,670 kg
Fuel Capacity 3.444 l
Maximum Speed 300 mph / 490 km/h
Cruising Speed 245 mph / 395  km/h
Range 790 mi /  1.270 km
Maximum Service Ceiling 27,890 ft / 8,500 m
Climb speed Climb to 3,000 m in  8 minutes
Crew Pilot, navigator, gunner and radio operator/gunner
Armament
  • Six 7.62 mm ShKAS machine gun
  • Two 1,000 kg bombs or Four 500 kg bombs

Gallery

Illustration by Godzilla

Credits

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

Sources

  • Y. Gordon, D, Khazanov (1999), Soviet Combat Aircraft Of The Second World War, Midland Publishing
  • Yefim G. and Bill G (2000), Soviet X-Planes, Midland Publishing
  • Peter G. D. (2015), Soviet Aircraft Industry, Fonthill Media
  • D. Nešić (2008), Naoružanje Drugog Svetskog Rata SSSR, Beograd.
  • Aviamuseum

 

 

 

Messerschmitt Me 163A Komet

Nazi flag Nazi Germany (1943)
Rocket Powered Fighter – 10 Built

The first operational Me 163 prototype. [luftwaffephotos.com]
During the Second World War, the Luftwaffe experimented with a number of unorthodox designs. This included a handful of rocket-powered aircraft, like the Me 163. This particular aircraft was created thanks to the somewhat unexpected combination of two different projects. One was the airframe designed by Alexander Martin Lippisch, and the second was the rocket engine developed by Helmuth Walter. Following the testing of the first prototypes, a small series of some 10 aircraft were built that were mainly used for testing and training.

Alexander Martin Lippisch and Helmuth Walter

The history of Me 163 was closely related to the work and design of aircraft engineer Alexander Martin Lippisch and rocket development pioneer Helmuth Walter. Lippisch was somewhat unorthodox in his aircraft design work, to say the least. He was quite interested in the development of gliders and later aircraft that were either completely lacking a tail unit or of an all-wing configuration.

In 1921, Lippisch, together with a colleague, participated in the formation of the so-called Weltensegler GmbH (World Glider Ltd.) company. At that time, the Germans were prohibited from developing and building military aircraft. The Germans worked around this prohibition by instead focusing on gliders and civilian aircraft which if needed would be quickly converted for military use, and conducted secret experiments. While glider development may seem like a waste of effort, it actually provided the Germans with an excellent foundation on which they managed to develop the Luftwaffe during the 1930s, becoming a formidable force at the start of the war. In 1925, Lippisch joined Rhön Rossitten Gesellschaft RRG, where he soon began working on his first glider. It was named Storch I, and incorporated his unusual all-wing design.

Over the years, Lippisch also became interested in rocket technology. With assistance from Fritz von Opel, Lippisch managed to build a rocket-assisted glider. This contraption was flight tested in June 1928. This was actually the first-ever rocket-assisted flight in the world. While initially successful, the glider crash-landed, and caught fire. The plane would be lost in the accident.

This accident did not prevent Lippisch from experimenting with rocket-powered all-wing gliders. He focused his work on a powered version of his Storch V glider. For this project, he used an 8 hp DKW engine. His work was successful and he managed to find investors who were willing to provide funds for the project. This led to the development of the Delta I all-wing aircraft during the late 1920s, and it was followed by Delta II, III, and IV.

Lippisch Delta I prototype. [aviastar.org]
Following this, Lippisch joined the Deutsche Forschungsinstitut DFS, where he worked as an engineer. There, he developed a series of new glider designs, like the DFS 40. In 1938, the work of Helmuth Walter came to his attention. Walter was a young scientist who was highly interested in rocket propulsion. He managed to gain military funding, which greatly helped in his work. In 1937, he even managed to gain attention from the Reichsluftfahrtministerium RLM (German Air Ministry). The RLM formed a Sondertriebwerke (Special Propulsion System Department) with the aim of experimenting with rocket engines in the aircraft industry. While this department was mainly focused on developing rocket engines for short take-off assistance, Walter desired a more prominent role in rocket propulsion. He intended to develop a rocket engine that could replace standard piston engines. Walter managed to develop such an engine, named Walter TP-1, which was fueled by the so-called ‘T-Stoff’ (hydrogen peroxide) and ‘Z-Stoff’ (water solution of either calcium or sodium permanganate). His engine design would be tested in 1939 on the He 176. However, the final results were disappointing and the engine did not go into production.

The DFS 194 predecessor

Lippisch and his design team began working on a new project incorporating the Walter rocket engine. Initially, the project was designated simply as Entwurf X (Design X), before being changed to 8-194 and finally DFS 194. Work on the prototype came to a temporary halt as the DFS lacked proper production capabilities to finish the aircraft. To keep the project going, the RLM instructed Messerschmitt to provide the necessary manpower and production support.

Given the small chance of progression in the DFS and in order to increase the speed of the project, Lippisch and his team moved to Messerschmitt’s base at Augsburg at the start of 1939. He also tried to negotiate with Heinkel for the production and development of the DFS 194 project, but nothing came of this. At Augsburg, Lippisch and his team worked in Messerschmitt’s newly formed Department L (which stands for Lippisch).

The DFS 194 prototype served as the base for the future Me 163. [nevingtonwarmuseum.com]
The first calculations were promising, as the plane would be able to reach a speed of 550 km/h (342 mph). Once completed the DFS 194, was transported to the secret German rocket test center at Peenemunde-West Airfield during the summer of 1939. During ground tests, it was noted that the engine installation was poorly designed and too dangerous to be actually flight tested. Instead, it was decided to use the design as a glider. Surprisingly, despite this huge setback, production orders for three prototypes were given. Initially, these were designated simply as Lippisch V1, V2, and V3, but would be renamed to Me 163A V1 to V3. This was mainly done to mask the true purpose of this aircraft, as this was the name given to an older, rejected Bf 163 Messerschmitt reconnaissance aircraft project.

The Me 163A Prototype Series

The RLM was not satisfied with the general design of the engine compartment initially tested on the DFS 194. They requested that for further Me 163 development, it would need to be substantially changed. In addition, the engine was to be replaced with the Walter R II-203 engine. This engine was to have a manually regulated thrust ranging from 150-750 kg of thrust (330-1,650 lbs). The engine compartment was also to be completely redesigned in order to have easy access to the main components for maintenance.

Following the start of the Second World War in September 1939, the work on the Me 163 slowed down but still went on. The first unpowered flight by the Me 163 V1 prototype, in some sources marked as V4, (KE + SW) was carried out during early 1941. This prototype was towed by a Bf 110 heavy fighter. Once at a sufficient altitude, the V1 was released. During the test flight, the pilot, Heini Dittmar, managed to reach a speed of some 850 km/h (528 mph) during a dive. While this was a great starting point for the project, Hitler, following military victories in Poland and in the West, ordered that funds for such projects be reduced. In the case of the Me 163, this meant that only two more additional prototypes were to be built.

Side view of the Me 163 V1 (V4).[luftwaffephotos.com]
In May 1941, a wooden mock-up of a Me 163 was completed, which was then transported to the Walter Werke. Once there, it was to be equipped with the R II-203 engine. Once the first prototype was fully completed and equipped with this engine, the first tests were carried out at Peenemunde-West in August 1941. The test pilot was once again Heini Dittmar. After a series of test flights that lasted from August to September 1941, the Me 163 prototype showed promising results. The pilot managed to reach top speeds of 800 km/h (500 mph). At this time, the second V2 prototype was also equipped with a rocket engine and used in various test flights. Ernst Udet, Director-General of the Luftwaffe, was highly impressed with its performance. He even gave orders that an additional 8 prototypes were to be built, bringing the total to 13 at this time.

Once the prototype was equipped with the R II-203 engine, the first tests were carried out in August 1941. These proved to be highly successful, which led to an increase in interest for the Me 163 project. [Spate & Bateson]
At the start of October, Heini Dittmar said that, in order to fully test the Me 163’s flying performance, the fuel load had to be increased. On his personal insistence, the V3 (CD + IM) prototype, was fully fueled. This is according to W. Spate and R. P. Bateson (Messerschmitt Me 163 Komet). Other sources like M. Griehl (X-Planes German Luftwaffe Prototypes 1930-1945) this aircraft was described as being the V8 prototype instead. On the 2nd of October 1941, he took to the sky, initially towed by a Bf 110. At an altitude of 3,960 meters (13,000 ft), Dittmar activated the engine. After reaching a speed of 965 km/h (600 mph), he lost control of the aircraft as the result of compressibility effects. The prototype began a rapid descent toward the ground. He then switched off the engine, which enabled him to regain control, after which he landed safely on the ground. Later analysis of the flight indicated that Dittmar managed to reach a speed of 1002 km/h (623 mph). As the whole project was undertaken under great secrecy, this success was not published at the time.

The Me 163 in the middle was the aircraft that Heini Dittmar flew when he reached a speed of 1002 km/h (623 mph). [Spate & Bateson]
Following these events, the Me 163 project got a temporary boost in prominence, with Herman Goring himself placing great interest in it. Ernst Udet additionally placed an order for 70 new Me 163 airframes together with engines for the B version in October 1941. A month later, things changed dramatically for Me 163 after Udet committed suicide. His replacement, Erhard Milch, was less interested in unconventional aircraft designs, like the Me 163. Work on the project nevertheless continued.

A breakup with Messerschmitt

While the Me 163 project was underway, relations soured between Willy Messerschmitt and Lippisch. Messerschmitt personally disliked the Me 163, partly due to its unique overall design, but also given that he was not involved in its development. By 1943, Lippisch left Augsburg and moved to Vienna. While not physically present in the design bureau, he tried to maintain contact with the Me 163 development team at a distance.

In the meantime, Messerschmitt was unwilling to be involved in the Me 163 project, under the excuse that his company was already overburdened with the production of other aircraft. For this reason, the production of further Me 163 aircraft was instead given to Klemm Leichtflugzeugbau, a relatively small aircraft company owned by Hans Klemm.

Production of the A-0 series

While the V1 prototype was mainly used for initial testing, the V2 would serve as a base for the A-0 series. An initial order for ten A-0 aircraft was previously given to Messerschmitt, but only seven were completed. The remaining three aircraft were actually completed by the Klemm factory. These were all completed from 1941 to 1942. The number of prototypes built is not clear in the sources. The numbers range from 1 to 8 prototype aircraft. According to S. Ransom and H.H. Cammann (Jagdgeschwader 400), while three prototypes were meant to be built initially, not all met the requested specifications, except one, which received the V4 designation. Author M. Griehl (Jet Planes of the Third Reich) on the other hand noted that the V4 was the first prototype. He explained that the previous three prototypes were actually related to the initial Bf 163 reconnaissance project that was rejected.

In-Service

Of the 10 built Me 163 A-0 planes, not all were equipped with fully operational engines. A number of them were instead operated as unpowered gliders. This version was not intended for combat operations and was mainly used for crew training and further experimentation.

At the end of November 1943, the V6 aircraft was lost in an accident with the loss of the pilot. In another accident at the end of 1943, another pilot died when the engine stopped working during a takeoff. While the pilot tried to turn back for a landing, having limited control, the aircraft hit a ground station radio antenna before hitting the ground and exploding. It was discovered in an investigation that the undercarriage dolly bounced off the ground much higher than usual, and struck the aircraft, damaging the rocket engine. Some prominent pilots, like Hanna Reitsch, actually had the chance to flight-test the Me 163 aircraft. At least one aircraft was still operational by February 1945 and was used for testing the 55 mm R4M rockets by Erprobungkommando 16.

Me 163A at Peenemunde, 1943. [Ransom & Cammann]
At least one Me 163A survived up to February 1945. It was used by Erprobungkommando 16 (Eng. testing or evaluation-coomand) in Silesia to test the 55 mm R4M rockets. This unit had the primary function of testing and examining the newly built Me 163 and helping in the development and improvement of its overall design. Besides these, no other armament was installed on the Me 163 A series. Source Source: W. Spate and R. P. Bateson Messerschmitt Me 163 Komet

Technical Characteristics

The Me 163A was a high-speed, rocket-powered, swept-wing, short fuselage, mixed-construction tailless aircraft. The Me 163A fuselage was built using metal, divided into three sections, the front cockpit, central fuel tank, and the aft engine compartment.

The wooden wings had a very simple design consisting of two spars covered in thick fabric. If needed, the wings could be detached from the fuselage for transport. At the wings’ trailing edges ailerons were placed, which the pilot during flight used for pitch and roll. The wing area was 17.5 m² (57.4 ft²). The tail did not have the standard horizontal stabilizers, instead of having a single large vertical stabilizer. Despite this, no major problems during flights were ever noted on the Me 163A.

For the pilot to enter the cockpit he was provided with a ladder placed on the left side of the aircraft. The cockpit canopy opened upwards. Overall visibility was poor, and later versions would have an improved canopy. While it did offer some improvements for the pilot’s line of sight, it would not resolve the overall poor visibility of the aircraft. Given that the Me 163A was based on a DFS 194 glider, it was equipped with minimal instrumentation needed for the aircraft to be flown.

View of the Me 163A’s cockpit interior. [Spate & Bateson]
The Me 163A was powered by a single HWK R II 203 rocket engine, which gave 750 kg (1,650 lb) of thrust. The main fuel consisted of a mix of T and Z Stoff. These two chemicals were highly reactive, volatile, and prone to explosion. To avoid this, extensive preparation and security measures were necessary. The maximum speed this engine achieved was some 850 km/h (530 mph). This high speed was achieved to some extent thanks to the aircraft’s low weight. The empty weight was 1,140 kg (2,513 lbs) while the maximum takeoff weight was 2,200 kg (4,850 lbs).

Interestingly, in order to save weight, the Me 163 did not have a conventional landing gear unit. Instead, during take-off, it was provided with a specially designed two-wheel dolly. It would be jettisoned upon take-off. When landing on the airfield, the Me 163 used a retractable skid located beneath the fuselage.

Despite the A series having not been designed to have any weapon systems, at least one Me 163A was tested with the installation of the 5.5 cm (2.16 in) R4M air-to-air rockets.

Production Versions

  • DSF 194 – Prototype whose further development led to the creation of the Me 163
  • Me 163 Prototype Series– Prototype aircraft
  • Me 163A-0 – 10 Pre-production aircraft built

Conclusion

The Me 163A series, despite its unusual appearance and overall design, proved to be a rather successful aircraft. It had some shortcomings, mostly regarding its dangerous fuel load. Upon completion of successful testing, order for the Me 163B version was given.

Me 163A Specifications

Wingspans 8.85 m / 29 ft 3 in
Length 5.25 m / 17 ft 2 in
Height 2.16 m / 7 ft 8 in
Wing Area 17.5 m² / 57.4 ft²
Engine One HWK R II 203 rocket engine with 750 kg (1,650 lbs) of thrust
Empty Weight 1,140 kg / 2,513 lbs
Maximum Takeoff Weight 2,200 kg / 4,850 lbs
Maximum Speed 850 km/h / 530 mph
Crew 1 pilot

Gallery

Me 163A – Illustrated by Carpaticus

Credits

  • Written by Marko P.
  • Edited by by Ed Jackson & Henry H.
  • Illustrations by Carpaticus

Sources

  • D. Nešić (2008) Naoružanje Drugog Svetsko Rata-Nemcaka. Beograd.
  • W. Spate and R. P. Bateson (1971) Messerschmitt Me 163 Komet , Profile Publications
  • M. Ziegler (1990) Messerschmitt Me 163 Komet, Schiffer Publishing
  • M. Emmerling and J. Dressel (1992) Messerschmitt Me 163 “Komet” Vol.II, Schiffer Military History
  • E. T. Maloney and U. Feist (1968) Messerschmitt Me 163, Fallbrook
  • S. Ransom and H.H. Cammann (2010) Jagdgeschwader 400, Osprey publishing.
  • D. Donald (1990) German aircraft of the WWII, Brown Packaging books ltd
  • D. Monday (2006) The Hamlyn Concise Guide To Axis Aircraft OF World War II, Bounty Books.
  • M. Griehl (1998) Jet Planes of the Third Reich, Monogram Aviation Publication
  • M. Griehl (2012) X-Planes German Luftwaffe Prototypes 1930-1945, Frontline Book

Heinkel He 112

Nazi flag Nazi Germany (1935)
Fighter – 66 to 100 Built

He 112 the unsuccessful competitor of the Bf 109. [luftwaffephotos.com]
Prior to the Second World War, the German Luftwaffe was in need of a new and modern fighter that was to replace the older biplane fighters that were in service. While four companies responded to this request, only the designs from Heinkel and Messerschmitt were deemed sufficient. The Heinkel He 112 was an especially good design that offered generally acceptable flight characteristics and possessed a good basis for further improvements. While it was in some regards superior to the Messerschmitt, ultimately it would not be accepted for service, and only 100 or so aircraft would be built. These would be mainly sold abroad, with those remaining in Germany used for various testing and evaluation purposes.

History

By the early 1930s the Heinkel company was a well-established aircraft manufacturer. It was rapidly expanding, mostly thanks to the export of some of its aircraft designs. The Heinkel company also had a good relationship with the German Air Ministry RLM (Reichsluftfahrtministerium RLM), which entered a series of different aircraft production contracts with Heinkel.

At this time the German Air Force was in the process of a huge reorganization, and the development of new military aircraft. Quite of interest was the development of a new fighter aircraft that would replace older Arado Ar 68 and Heinkel He 51 biplanes that were in service. For this reason, in May 1934 the RLM issued a competition for a new and modern fighter plane that could reach speeds of 400 km/h (250 mph) at an altitude of 4,000 meters (19,685 feet). Initially, three companies were contacted, including Arado, Focke-Wulf, and Heinkel. Interestingly, and somewhat ironically as it later turned out, Messerschmitt, a relatively small company at that time, was also contacted by the RLM.. All four companies were to build three prototypes of their design, which were to be tested before a final decision was to be made.

Arado and Focke-Wulf completed their prototypes, the Ar 80 and Fw 159 respectively, by the end of 1934. The Heinkel He 112 and Messerschmitt Bf 109 prototypes took a bit longer to complete, which was completed in September 1935. The He 112’s design was greatly inspired by the He 70 passenger plane, which would later be modified for military purposes. Heinkel engineers used the He 70’s the overall design as the basis for the He 112, mainly regarding its wings and the fuselage construction.

The inspiration for the He 112 was the He 70. While the He 70 had good general performance it would not be employed by the German in any major military role. [Wik]
Once all four companies submitted their designs, evaluation trials were carried out at the German test centers located at Rechlin and Travemunde starting in October of 1935. After some initial testing, both the Ar 80 and Fw 159 experienced too many mechanical breakdowns and even crashes, which ultimately led to both being rejected. The He 112 and Bf 109 on the other hand proved to be more promising designs. Interestingly due to shortages of domestically built engines, both aircraft were initially powered by Rolls-Royce Kestrel engines.

The He 112 V1 (D-IADO) was powered by a 695 hp Rolls-Royce Kestrel Mk. II engine during trials. Once the aircraft was completed, it was first flight-tested by Heinkel’s own test pilot Gerhard Nitschke. While he gave a generally positive review of its performance, he also noted the aircraft’s drag was a bit higher than expected. However, given that its overall performance was deemed sufficient for the competition, Heinkel decided to proceed with the project. This prototype arrived at the designated test center of Travemunde by the end of 1935. During a series of flight tests, the maximum speed achieved was 466 km/h (290 mph).

The He 112 V1 first prototype, used for the trials held at Rechlin and Travemunde. [luftwaffephotos.com]
It was clear that the RLM would never accept an aircraft powered by a foreign engine. The Heinkel engineers began working on the second prototype that was to be equipped with a domestically built engine. The V2 (D-IHGE) was powered by a 640 hp Junkers Jumo 210C liquid cooled engine. The first test flight was made in November 1935 by another Heinkel test pilot Kurt Heinrich. The V2 was more or less just a copy of the first prototype.

Construction of Additional Prototypes

During the series of test flights, the performance of the two competitors was quite similar, with some minor advantages between them. In the case of the Bf 109, it was slightly faster, while the He 112 had lower wing loading. In addition, the He 112 had a better design and safer landing gear unit.

As the V2 was flight tested at Heinkel, the initial results of the competition began to arrive. The Heinkel engineers were keen on finding a way to overcome the Bf 109’s slightly faster speed. So the Gunter brothers began to redesign the V2 wings. Walter and Siegfried were at that time, probably Heinkel aircraft designers (for example the He 51 biplane is one of their designs.). Their calculation showed that a reduction in the wing profile would provide an additional boost to the maximum speed by at least 24 to 29 km/h (15 to 18 mph). This modification reduced the overall size of the wings, but led to another problem. Namely, the wing loading exceeded that of the RLM commission requirement. Given that the aircraft speed was increased, Heinkel officials deemed that it was a necessary compromise that would not affect the general rating of the aircraft.

The V2 prototype reached the Travemunde test center sometime in early 1936. In February 1936 the V1 and V2 prototypes were moved to the Rechlin Testing Center. In early March, a series of dive tests were carried out. In one of these, the V2 was seriously damaged, luckily the pilot survived the crash. After a few weeks of repairs with Heinkel, the aircraft was quickly put back to use. But in another landing crash, it was completely destroyed and listed as irreparable. Once again the test pilot managed to escape without any injury. This accident, while it did not prevent Heinkel’s involvement in the new fighter competition, it certainly affected the commission’s opinion on the He 112 at least to some extent.

The last of the prototypes intended for the competition was the V3 (D-IDMO). While initially, it was more similar to the first prototype, it received the wing modification implemented on the V2. Additional changes include increasing the rear tail unit size, adding a new radiator, installation of three (or two depending on the source) 7.92 mm MG 17 machine guns. In addition, it would later receive a new enclosed cockpit with a sliding canopy.

Side view of the V3 (D-IDMO) prototype. [luftwaffephotos.com]

Further Competition Developments

Despite the series of improvements to their He 112 design, the tide was slowly but surely turning toward the Bf 109. The RLM commission was getting somewhat frustrated with Heinkel’s constant changes to the design, and the previously mentioned crash did not help matters. In March, it was already being discussed to proclaim the Bf 109 as a winner. The Germans were also informed by the Abwehr intelligence service that the British were developing and preparing for the production of the new Spitfire. RLM officials were simply not willing to risk taking a chance on an aircraft design that could not quickly be put into production, as the Bf 109 was.

While the He 112 project would have ended there, thanks to Heinkel’s strong political connections, an extension of the trials was agreed to. Both companies were to build additional 15 0-series aircraft to be used for testing. The production was to commence in October 1936 with the last aircraft to be completed by May the following year.

Heinkel’s first completed aircraft, which was included in the previously mentioned contract, was actually a He 112 V4 (D-IDMY) prototype which was ready in June 1936. The V4 received a new and stronger 680 hp Jumo 210D that was equipped with a supercharger. In addition, it had an open cockpit, besides which it was in essence a copy of the V3. Possibly anticipating the contract for additional aircraft, Heinkel began working on additional airframes in advance. This led to the completion of the V5 (D-IIZO) and V6 (D-IQZE) prototypes in July of 1936. The V6 was intended as a replacement for the lost V2 aircraft. This aircraft was powered by a Jumo 210C engine. The last aircraft of the prototype series was the V8 (D-IRXO) powered by a Daimler DB 600A engine. It was primarily intended to serve as test aircraft. All of these previously mentioned prototypes were to serve as the forerunners of the He 112 A-0 series.

The V4 prototype before it received any markings. [luftwaffephotos.com]
Following more test flights by numerous Luftwaffe pilots, the Bf 109 was receiving more and more positive reviews from pilots that had the opportunity to fly them. The Bf 109, while proving to have excellent flying performance, was also cheaper and easier to build than the He 112. Given the fact that the Germans were attempting to accelerate the production of the new fighter, this was seen as a huge advantage over the He 112.

In late 1937 Ernst Udet, who was at that time the director of the RLM technical development sector, visited the Heinkel company Marienehe Test Site. There he informed Heinkel that his He 112 was rejected as a fighter. Possibly to compensate for the huge investment in the fighter project, Heinkel company was permitted to export the He 112.

Heavy Fighter Role

Parallel with the development of the first fighter aircraft, the RLM was also interested in the so-called Zerstorer (heavy fighter). This aircraft was to be armed with cannons and machine guns. Heinkel proposed that the V6 be armed with a 2 cm MG C/30L cannon placed in the centerline of the engine. According to D. Bernard the V6 was designated for further testing, under real combat conditions, and would be sent to Spain at the end of 1936. It would be lost there in a landing accident in July 1937. Ernst Heinkel was likely dissatisfied with this outcome, as Messerschmitt once again triumphed as its Bf 110 would be accepted for this role.

The A and B series

Despite being inferior to the Bf 109, the Heinkel company continued working on the He 112, improving its design, in the hopes of gaining the attention of the RLM. The construction of the limited production He 112 A-0 series was still underway, with a total of only six aircraft (D-ISJY, D-IXHU, D-IZMY, and D-IXEU) built. The last two aircraft of the A-0 series received no registration numbers, as they were intended to be sold to Japan. The remaining four aircraft were used for various proposals. For example, the A-01 aircraft was to be used as a base for the proposed He 112 C-0 aircraft carrier modification, which was never implemented. The A-02 and A-04 were used for further flight tests. The A-03 was mainly used as an exhibit aircraft for various European aviation exhibitions, which were quite common before the war.

The A-series was built in small numbers and mostly employed for testing various equipment and design changes. [luftwaffephotos.com]
The A-series was built in small numbers, as Heinkel’s attention moved to the B-0 series instead. The B-0 series was quite different from the previous version, as it introduced a number of changes and modifications. Some of which included a new cockpit design, more powerful armament, changes to the engine ventilation design, fuselage and engine cowling changes, and other modifications.. The forerunner of the B series was the He 112 V7 prototype, which included many modifications previously mentioned.

Following the unsuccessful attempt to gain the Luftwaffe’s attention Heinkel and his team of engineers began working on redesigning the He 112. The basis for the next version, the He 112B-0, the V7 (D-IKIK) was reused. It incorporated a newly redesigned wings and tail unit, and was to be powered by a 1,000 hp Daimler DB 600A engine. Heinkel officials and Hertel himself were hoping that this new version could potentially persuade RLM to reconsider the He 112. Following it was the V9 (D-IGSI), which was powered by a weaker 680 hp Jumo 210E engine. In the following months, work on the B-series was intensified with many different engines being tested (Jumo 210E, 210G etc). Ultimately meager export sales, and the RLM’s rejection of the He 112 by the start of 1939 forced Heinkel to finally terminate the project.

The B-series was in many aspects a complete redesign from the previous series. Including the introduction of a new tail unit, and part of the fuselage, to name a few [luftwaffephotos.com]

Rocket Engine Tests

Prior to the Second World War, the Germans were quite interested in the experimentation and the development of rocket technology. Various tests conducted by Dr. Wernher von Braun were carried out at the Kummersdorf-West test centers. While this research eventually led to the creation of the infamous V-2 rocket, the development of rocket engines that were intended to possibly be installed in aircraft is often overlooked. Ernst Heinkel was quite a supporter of this project and even donated a number of aircraft to be used as testbeds for the potential new engine. He even donated a few pre-production series He 112 for this research.

A rocket engine was installed in the rear of the fuselage, with the engine nozzle being placed just beneath the tail unit. During the first ground test, the engine exploded, destroying the aircraft (He 112 A-01) in the process. Another He 112 V3 aircraft was outfitted with the rocket engine and was being prepared to conduct its first test flight. As the pilot was approaching this aircraft, the rocket engine exploded again. Somewhat miraculously the pilot survived with no major injuries. While again the aircraft was lost, another aircraft that was built as a replacement would receive the same markings.

The V3 prior to the start of testing. Which would spectacularly explode shortly after the picture was taken. [luft46.com]
Von Braun requested another aircraft which Henkel provided, this was the He 112 V8. During these trials it received a slightly altered designation V8/U. The plane was to ascend on its own piston engine. Then at a certain height, it was to fire the rocket engine wich was placed to the rear of the fuselage for a 30-second burst. This flight test was carried out in April 1937 and was more than successful. During the short burst, the plane reached a speed of 460 km/h (286 mph). The He 112 V8 was returned to Heinkel but two more aircraft (H7/U and A-03) would be donated for the rocket research program. The V8 would be eventually sent to Spain in 1937 and its final fate is unknown. Thanks to the He 112, the German rocket engine program gained a huge boost, which would eventually lead to the He 176 and later Me 163.

Technical Characteristics

The He 112 was an all-metal single-engine fighter. The monocoque fuselage consisted of a metal base covered by riveted stress metal sheets. The wing was slightly gulled, with the wingtips bending upward, had the same construction as the fuselage with a combination of the metal construction covered in stressed metal sheets.

During its development life, a great number of different types of engines were tested on the He 112. For the main production version, He 112 B-2, the 700 hp Jumo 210G liquid-cooled engine was used. With this engine the maximum speed achieved was 510 km/h (317 mph). For the Jumo engine, an all-metal three blade variable pitch propeller was used. The He 112 had a fuel capacity of 101 liters in two wing mounted tanks, with a third 115 liter tank placed under the pilot seat

The landing gear were more or less standard in design. They consisted of two larger landing wheels that retracted into the wings, and one smaller wheel placed at the rear. The He 112 landing gear was wide enough to provide good ground handling and stability during take-off or landing.

The pilot cockpit received a number of modifications. Initially, it was open with a simple windshield placed in front of the pilot. Later models had a sliding canopy that was either partially or fully glazed.

While the armament was changed during the He 112’s production, the last series was equipped with two 7.92 mm MG 17 machine guns and two 2 cm Oerlikon MG FF cannons. The ammunition load for each machine gun was 500, with 60 rounds each for the cannons. If needed, two bomb racks could be placed under the wings, with one per side. Each could carry one 10 kg anti-personnel bomb. For the acquisition of targets, the pilot used the Revi 3b gun sight.

Brief Service with the Luftwaffe

Despite losing to the Bf 109, Heinkel was permitted, after some lobbying from Ernst Heinkel himself, to send one He 112 to Spain for combat evaluation. Once it reached Spain during the end of 1936, the He 112 was allocated to the Experimental Fighter Unit 88 which was part of the Condor Legion. In Spain, it was mostly used against ground targets. One of its greatest successes happened during an attack on the Republican-held Cesena train station. The pilot, Obereutnant Balthasar, made three attack runs in which he managed to destroy an armored car and a tank. The aircraft would be lost in a landing accident that happened in July 1937. Two more prototypes would be sent to Spain during 1938, the V8 and V9. The V8 was heavily damaged during initial trials and spent some four months in repairs. The V9 had a better service life, as it was used in a number of ground attacks. Both aircraft would be returned to Germany by the end of 1938.

Only a small number of He 112 (less than 20) saw limited service with the Luftwaffe in 1938 [luftwaffephotos.com]
In 1938 a possible conflict with Czechoslovakia and the Western Allies, France, and the United Kingdom over the dispute caused huge concern in the RLM. The Luftwaffe was simply not ready for open war, as it was not yet fully equipped. For this Reason, the RLM instructed that all available aircraft be relocated to the Luftwaffe to temporarily boost their readiness numbers. An unknown number of He 112 B, taken from the Japanese purchase order, were temporarily pressed into service. These were allocated to the IV./JG 132 station at Oschatz. In November they relocated to Mahrish-Trubau. Once the crisis was over, the aircraft were replaced with the Bf 109. The pilots that had the chance to fly them gave a generally positive review of their flying performance.

Export Attempts

As mentioned earlier, the He 112 was permitted to be exported abroad if there were any interested customers. This order was officially given at the end of January 1938. A number of countries such as Austria, Japan, Romania, and Finland showed interest, but only a few actually managed to procure aircraft.

Negotiation with Austria

During November 1937 an Austrian delegation visited Heinkel with a desire to enter into a purchase agreement for acquiring 42 He 112B aircraft. Due to lack of funds, this order was reduced to 36 at the start of 1938. Eventually, nothing came of this as the Germans simply took over Austria in March 1938.

In Japanese Hands

At the end of 1937, a Japanese delegation made a contract with Heinkel for purchasing 30 He 112B’s. If these proved to be satisfactory, an additional order for 100 would be placed. This order included 2 He 112 A-0, 6 B-0, and 21 B-1 and the V11 prototype. After a series of tests, the Japanese were not impressed with the He 112 and did not accept it for service. The experimental He 112 C aircraft carrier version was also sold to Japan, according to D. Bernard.

J. R. Smith and A. L. Kay provide a completely different story. According to them, Japan expressed an interest in buying 30 He 112B-0 aircraft, with the first group of 12 aircraft arriving in Japan in 1938. While the remaining 18 were to arrive soon after, the Sudeten crisis changed the plan. The Germans were preparing for a potential war with Czechoslovakia and needed every possible aircraft. So they requisitioned the aircraft intended for Japan. Once the crisis was over, Heinkel offered to ship these delayed aircraft to Japan, which rejected the offer. The Japanese were disappointed with the He 112 B-0 performance and decided to cancel the purchase. The sources also conflicted with each other if the He 112 in Japanese service ever saw action.

In Spain

Some three He 112 were tested during the Spanish civil war. Thanks to this, Francisco Franco’s forces had some insight into the He 112’s performance. Based on this, Spain initially asked for 12 aircraft. The order would be eventually increased to 18 aircraft. Interestingly, Spanish pilots managed to shoot down an Allied P-38 that likely accidentally entered the Spanish air space while flying the He-112B-0 in 1943.

He 112 in Spain’s service. [luftwaffephotos.com]

In Romania

Romania initially asked for 24 aircraft, with the order later increased to 30 He 112 aircraft. These arrived from June to October (or September) 1939. The Romanian He 112 would be used during 1941 against the Soviet Union. The following year, all would be allocated for pilot training.

Romanian He 112 even saw service against the Soviet Forces during 1941. [luftwaffephotos.com]

Hungary

The last nation that operated the He 112 was Hungary. In September 1937 a delegation from Hungary visited Heinkel where they inspected the He 112. This delegation was satisfied with what they saw and ordered 36 aircraft, but also showed interest in a licensed production. Ultimately the RLM rejected this offer and only one aircraft ever reached Hungary.

Other Unsuccessful Negotiations

Prior to the war, Heinkel organized a series of demonstrations of the He 112B to various interested European air forces. These include Yugoslavia, The Netherlands, Finland, Turkey, and Switzerland. While many of these parties were interested, for various reasons, chiefly budget constraints, nothing came of these negotiations.

Production

The production numbers of the He 112 are not clear and vary widely depending on the source. According to F.A.Vajda and P. Dancey the production run was as follows with 3 in 1935, 11 in 1936, 13 in 1937, 30 in 1938, and 46 in 1939 for a total of 103 aircraft. Author D. Berliner mentioned a number of 66 aircraft being built. Author Duško N. gave a number of 68 aircraft of all versions being built. D. Bernard gave us a number of 98 aircraft. While C. Chants mentioned a number of 110 aircraft.

Prototype and Production Versions

  • He 112 V1-V – Prototype series used for testing of various engines and overall design
  • He 112 A – Planed main production version, which was not adopted
  • He 112 B – Extensively modified versions of preceding models
    • He 112 B-1 – Equipped with a Jumo 210E engine
    • He 112 B-2 – Equipped with a Jumo 210G engine
    • He 112 B-3 – Proposed version powered by a Daimler DB 601A engine, none built
  • He 112 C – A proposed aircraft carrier version, only one prototype was built and sold to Japan
  • He 112 E – Intended as an export version, based on the B series
  • He 112 U – Propaganda aircraft, which was actually based on the He 100

Operators

  • Germany – Briefly operated a small number of the He 112
  • Japan – Operated some 12 to 30 aircraft mainly for testing
  • Spain – Operated less than 20 He 112 aircraft
  • Romania – Purchased some 24 to 30 He 112, which saw combat action against the Soviet Union
  • Hungary – Purchased one He 112
  • Austria – Planned to acquire 42 He 112, but nothing came from this as it was annexed by Germany.

Conclusion

The He 112 during its brief service life was shown to be a good fighter aircraft. It proved to be a worthy competitor to the Bf 109. It’s quite difficult to pinpoint the exact circumstances that ultimately led to its downfall. Sources often mention that one of the main reasons was political involvement, which favored Messerschmitt. Political quarrels in Germany often influenced decision to adopt aircraft during the war. This factor was surely at play when the fate of the He 112 was decided. But a more practical answer was simply that the Bf 109, while shown to have good flying performance, was also cheaper and easier to build than the He 112. Given that at that time, the Luftwaffe was in the middle of a huge reorganization and rearmament effort, conditions certainly favored the Bf 109. The He 112’s constant design changes did not help either.

He 112B-2 Specifications

Wingspans 29 ft 10 in / 9.1 m
Length 30 ft 2 in / 9.22 m
Height 12 ft 7 in / 3.82 m
Wing Area 180 ft² / 17 m²
Engine One 700 hp Jumo 210G liquid-cooled engine
Empty Weight 3,570 lbs / 1,620 kg
Maximum Takeoff Weight 4,960 lbs / 2,250 kg
Climb Rate to 6 km In 10 minutes
Maximum Speed 317 mph / 510 km/h
Cruising speed 300 mph / 484 km/h
Range 715 miles / 1,150 km
Maximum Service Ceiling 31,170 ft / 9,500 m
Crew 1 pilot
Armament
  • Two 20 mm cannons and two machine guns 7.92 mm  machine guns

Illustrations by Godzilla

He 112 as seen during its brief service with the Luftwaffe
An alternate livery of the Luftwaffe He 112
He 112 in Romanian Service
He 112 in Romanian Service
He 112 v5 as it was tested by Japan

Credits

  • Written by Marko P.
  • Edited by by Ed Jackson & Henry H.
  • Illustrations by Godzilla

Sources

  • Duško N. (2008) Naoružanje Drugog Svetsko Rata-Nemаčaka. Beograd.
  • D. Monday (2006) The Hamlyn Concise Guide To Axis Aircraft OF World War II, Bounty Books.
  • D. Berliner (2011) Surviving fighter aircraft of World War two, Pen and sword
  • F.A.Vajda and P. Dancey (1998) German aircraft industry and production 1933-1945, Airlife Publishing Ltd.
  • J. R. Smith and A. L. Kay (1990) German Aircraft of the Second World War, Putnam
  • D. Bernard (1996) Heinkel He 112 in Action, Signal Publication
  • R.S. Hirsch, U, Feist and H. J. Nowarra (1967) Heinkel 100, 112, Aero Publisher
  • C. Chants (2007) Aircraft of World War II, Grange Books.

 

North American P-51B Mustang

sweden flag USA (1943)
Fighter Aircraft – 3,738 Built

 

A P-51B undergoes testing at a Lockheed reassembly plant in Liverpool, UK. December 1943. [National Archives]
Initially developed to provide an export alternative to the P-40 for France and the UK, North American’s P-51 would prove to be a superb aircraft that would rank among the most decisive weapons of the Second World War. With its streamlined airframe and highly efficient cooling system, the aircraft would reach new heights when equipped with the far more advanced Packard Merlin engine. Though its early years would prove troublesome, it would solve long standing issues regarding the lack of long range bomber escorts, and achieve a level of performance beyond its Axis contemporaries.

Interwar Fighter Developments

The Merlin powered P-51’s share the distinction of being among the most successful fighter aircraft ever developed, but also having one of the convoluted development paths of any mass production fighter. While the aircraft would make its first flights in 1943, it had its roots in the late interwar period where many of the technologies it incorporated were first established.

US interwar fighter development saw rapid technical advancement, but a comparatively small build up of planes. Here an XP-40 undergoes wind tunnel testing, the design would go through a number of changes that would result in the P-40. [This day in Aviation]
The general environment of interwar fighter development for the US Army Air Corps was one of high theoretical advancement, but comparatively slow practical development. While major milestones were made in regards airframe and powerplant design, there was considerably less urgency to develop and mass produce fighters for use by the Air Corps. This was mostly a result of an isolationist foreign policy, which limited availible resources, and to a lesser degree, a desire within the Air Corps to focus on bomber procurement. While the development of new fighters was limited, the Air Corps had great freedom in procuring aircraft for testing purposes. While funding was still limited, they were allowed to procure up to 14 examples of an aircraft through their budget before they would need to petition Congress for additional funding. While a large build up of the Air Corps during this period was a financial and political impossibility, it would prove sufficient for exploring aircraft design and development. This environment would exist into the late 1930’s as the political situations in both Europe and Asia destabilized, and subsequently, the order was given to continue the development of the XP-38, XP-39, and XP-40 into new fighters for use with the Air Corps (Ethell 9).

While these aircraft were being prepared for service, vital new developments were being made in regards to airframe design. At the National Advisory Committee for Aeronautics (NACA) offices at Langley field, efforts had been made to produce airfoils which could achieve laminar flow. In short, this effect is characterized by minimal disruptions to the airflow of the surfaces of the wings and adjoining fuselage. In the context of fighter aircraft, this allowed for a much lower drag coefficient, which would permit better acceleration and would lessen the instability encountered at higher Mach numbers. They would achieve this by June of 1938 when an airfoil displayed laminar flow characteristics in wind tunnel tests (Ethell 10).

Europe Ablaze

The escalation to and the outbreak of hostilities in Europe would completely dispense with the interwar malaise and saw the US begin a massive arms build up. The most notable shift in policy was President Franklin Delano Roosevelt’s call for 50,000 aircraft in January of 1940. The resulting surge of orders would end up leaving most US aircraft manufacturers at capacity, and though they would satisfy domestic demand, the fulfillment of export orders was not a priority. This represented a serious issue facing the Allies in Europe. At the outbreak of the war, the French and British air forces were still largely in the process of expanding and modernizing. While they both possessed examples of modern fighter aircraft, such as the Dewoitine D.520 and Supermarine Spitfire Mk.I’s respectively, they also employed a large number of outdated aircraft in comparison to the better equipped German Luftwaffe. The expedient solution to this problem seemed to be to purchase aircraft abroad, and the US was by far the best source.

To this end British and French interests were served by the British Purchasing Commission. While they had decided on the ideal candidate being the Curtis-Wright P-40, they found the at-capacity firm unwilling to compromise its contracts to the US Army. They were soon negotiating with other firms for P-40’s which would be manufactured under license, and by 1940 had placed as many orders as they could. It was clear to all parties involved that any of the larger firms that were involved in US rearmament would be unable to deliver any sizable number of aircraft to the Allies. In January of 1940, Oliver Echols, in charge of Air Corps procurement, would suggest to the Purchasing Commission to approach a manufacturer that lacked any major contracts involved with US rearmament (Ethell 10).

This suggestion would see the British Purchasing commission returning to older offers from firms that they had turned down the previous year. The most important of these would be North American Aviation. North American had earlier proposed to build P-40’s under license for the Allies, though the offer was given little consideration (Ethell 10). They were likely turned down over their relative inexperience in the field of fighter aircraft, having previously built advanced trainers, like the AT-6 Texan, and the crude NA-50 and NA-68 export fighters. In spite of this, and finding few options among other US aircraft manufacturers, the British Purchasing commission would once again approach North American. This time however, North American was given the option to either produce license-built P-40’s, or instead to design a new aircraft with the aid of research data acquired from Curtiss-Wright on the XP-46 fighter prototype. NAA’s small, but enthusiastic team would choose the latter, and prepared to design a new fighter built around the Alison V-1710 engine.

Enter North American

North American’s greatest claim to fame before the Mustang was the AT-6, arguably the best advanced trainer of its day. [Wikimedia]
By the standard’s of most US industries of the time, North American Aircraft was a fledgling company, though one with great promise. It was originally formed as a holding company in 1929 to purchase stock in other aviation concerns, and was later incorporated under General Motors’ General Aviation branch. As a holding company, North American would gather a considerable amount of resources in these early years, of particular note was the firm’s acquisition of Fokker. In 1934, as a result of new regulations on air mail carriers, General Motors was required to divest itself of North American, which then became an independent firm. Thereafter, North American incorporated its parent company, General Aviation, and continued under the direction of its president James H. ‘Dutch’ Kindelberger (O’Leary 9). He would subsequently take the company west in 1936 where they would open a new facility at Mines Field, California. Prior to the war they would develop the O-47 reconnaissance and observation aircraft, which had begun under General Aviation, and the AT-6 advanced trainer, which was among the most successful designs of its type. They would also produce a set of unsuccessful export fighters which were altogether unimpressive. With this in mind it’s understandable North American was initially passed over, they were in fact, inexperienced in fighter development and their only real foray into that field was a disappointment. However, when the British Purchasing commission returned to the company in 1940, they found the firm more than ready to meet their needs. Their contract was worked out for 400 planes at a price no higher than $40,000 dollars a unit, and spare parts in the amount of 20% of the value of the aircraft.

The first step in developing the new fighter was purchasing the most recent data on fighter design from Curtiss-Wright’s XP-40 and XP-46 prototypes, and acquiring the new breakthrough aerofoil designs recently developed under NACA (Ethell 10, 11). This information was made available to the design team headed by Edgar Schmued, a German born aeronautical engineer who had previously been a GM field service manager for their Brazil branch. The work soon began on a new fighter under the designation NA-50B, later changed to NA-73, under a common and straightforward design strategy. Schmued would work to build a plane that would excel by incorporating all of the most recent developments in fighter design to produce an aircraft that was both cutting edge, yet conventional (Douglas 252). The Curtiss-Wright prototypes were a starting point that was quickly surpassed, with engineer and aerodynamicist Ed Horkey considering the prototypes too dated for use on the new project, and the data was discarded (Forsyth 13). This came as somewhat of a blow considering they were forced to pay about $50,000 for the test data. The same cannot be said for the data acquired from NACA.

Edgar Schmued would join North American through its parent company’s acquisition of Fokker. He would lead the team responsible for designing the Mustang which would be developed continuously through the Second World War. [alchetron]
Horkey would come across NACA’s research through a confidential release for American industrial use, and was convinced that it would make an excellent addition to the new fighter’s design. NAA would send a representative to collect the data from NACA at Langley Field, and they would go on to receive minor technical support. While the design did not possess true laminar flow characteristics, it did drastically reduce drag and improve the performance of the aircraft (Ethell 11). Further streamlining was achieved through the mounting of a low drag, centerline radiator which incorporated the work of British scientist, Dr. F.W. Meredith. This divergent-convergent duct was capable of using the heat ejected by the radiator to actually produce thrust and offset some of the speed loss incurred by drag incurred by the radiator’s air scoop (Douglas 252).

 

Great care was taken to build the prototype in good time. The NA-73X, would make use of a number of components from North American’s AT-6 trainer, including its landing gear, hydraulics, and electrical systems. Remarkably, the construction of the prototype was completed on the 102nd day of the project, but it would have to wait another 20 days for its Allison V-1710-39/F3R engine (Marshall & Ford 94). The supply of Allison engines at the time was constrained, and resulted in the project having to delay its deliveries to the British. Despite this, the fast pace of the program, and the fall of France would see the British order another 320 aircraft before the prototype even flew. With the program approaching testing, the British were awaiting the results and readying their own test pilots to become acquainted with the new plane. The prototype was first flown by American test pilot Vance Breese on the 20th of October, 1940. It would go on to make several more test flights before having to be repaired after an accident with test pilot Paul Balfour. The accident was a result of pilot error, who failed to switch over from an empty fuel tank, and as such the incident did not reflect poorly on the design itself (Marshall & Ford 151). As the sleek new fighter was taking shape, the British Purchasing Commission would notify NAA that the aircraft’s RAF designation was to be the ‘Mustang’ in a communique sent in December 1940 (O’Leary 24).

This prototype NA-73 was delivered to the US Air Corps for testing, though they would not place orders for Mustangs until a later date. [This day in aviation]
Among the last modifications to the NA-73 regarded its armament, fuel capacity, and reinforcement of its wings. Several proposals for its armament were considered, but for the British Mustang they installed a pair of .50 caliber guns in the nose cowling with another two .30 caliber guns in each wing. With these last additions made, the British soon received several of the new aircraft, which now bore the more familiar title of Mustang. The first, AG345, would be put through tests to find any issues from the transition from the NA-73. Several issues arose over the stiffness in the ailerons, power surges in dives, and overheating. These were subsequently addressed, though more drastic changes were needed in the case of the engine, which required installing a new carburetor scoop, and altering the scoop for the radiator (Marshall & Ford 165). The culmination of these new changes would result in the finalized Mustang Mk.I, and a second development prototype, NA-83.

While the aircraft’s development was proceeding at a rapid pace for the British, the USAAC would show very little initial interest in the Mustang. The aircraft the USAAC had dubbed the XP-51 was largely overshadowed by other developments and comparatively little effort was made to conduct exhaustive tests on the XP-51 prototypes at Wright Field to correct their faults. Their interest in the aircraft would be piqued only after the U.S. entrance into the second World War.

Mustang Mk. I

In British service the Mustang would take a different developmental path than what was proceeding in the United States. While the British were receiving their Mustang fighter aircraft, the US had been forced to develop the aircraft into a dive bomber, the A-36, as funds for fighter development had been expended for 1942. In the case of the RAF, the Mustang Mk. I went into service as soon as was practicable and saw their first squadrons, numbers 161 and 613, receive supplies of the new aircraft in April of 1942. They would first be employed as reconnaissance aircraft before later taking on more dangerous work during Operation Jubilee in which they undertook offensive recon sorties over the raid area in Dieppe, France. Beyond this they would be subsequently used to fly nuisance raids and fighter sweeps across the low countries. Its long range, high speed, and effective armament were used to great effect over these areas as they harassed rail and road communications, while also remaining quite capable against enemy fighters wherever they were encountered (Ethell 24, 25). Even by this early mark, the once uncertain contract they signed with North American had already paid off.

It was during this period that the aircraft’s faults and strengths would make themselves evident. The nose mounted guns were troublesome and complicated maintenance; they were often removed from operational planes and were eliminated from the succeeding models of the aircraft. The radiator still presented teething issues, as under certain conditions the oil could freeze over and would fail to circulate, and eventually cause the radiator to boil over. Visibility too would become an issue, as the canopy frame of the cockpit severely restricted the pilot’s view. However despite its faults, the plane was fast, possessing good acceleration and a high top speed that made it capable of outrunning all fighters in the theater at sea level (Ethell 24).

The Mustang Mk.I would prove an exceptional fighter with the RAF, if at first, a little rough around the edges. [wikimedia]
While the radiator issues would be addressed and a new bubble canopy was developed, another, more serious drawback of the design would require far more resources to address. The Allison engines that the early Mustangs were equipped with were considerably lacking when it came to high altitude performance due to their single stage, single speed superchargers. While the aircraft received good marks for its low altitude performance from pilots in the RAF, above the 15,000ft the Allison V-1710 suffered considerable power loss. Though this was by no means surprising, it represented an area where performance could be significantly improved. At higher altitudes the aircraft was outpaced by both contemporary models of the Fw 190 and Bf 109. At low altitudes, it was made somewhat redundant by the RAF’s new Hawker Typhoon, which both flew faster at low altitudes and was better armed. It wasn’t long until the idea arose to fit the Mustang with an engine possessing better high altitude performance, a combination that might well produce an exceptional fighter that was as capable at high altitude as it was down low (Douglas 253).

The first major step toward this came on April 29, 1942, when Wing Commander Ian Campbell-Orde invited one of Rolls Royce’s test pilots, Ronald W. Harker, to test the new aircraft. Harker was impressed by its performance and he believed that if the aircraft was fitted with the new Merlin 61, it would be able to outpace a similarly equipped Spitfire by a considerable margin (Marshall & Ford 215). The Merlin 61 was the obvious choice for many reasons, chief of which was its two stage, two speed supercharger which stood to offer the plane exceptional high altitude performance. To this end, a Mustang Mk.I was provided to Rolls Royce at Hucknall to undergo the necessary modifications. By the beginning of June 1942, the British had correctly projected that the Mustang’s top speed would be increased to 430mph at an altitude of 25,000ft, which was roughly twice as fast as the Allison powered Mustang at that altitude (Douglas 254). When the test aircraft was complete the results were quite impressive, as during a fly off between a Spitfire Mk. IX and a Mustang, both fitted with Merlin 61’s, the Mustang quickly outpaced the Spitfire.

Across the Atlantic, a parallel development began underway after a study of the Mustang’s combat debut with the RAF. The new United States Army Air Force, no longer constrained by funding, rushed to acquire supplies of the Mustang, and sought to re-engine the fighter to improve its high altitude performance. To this end, two P-51’s were set aside for conversion. By the early half of the Summer of 1942, both British and American Mustang experiments were underway. While the Mustang was previously seen as a side project which was never a wholly American or British effort, it was by then extremely clear that the design had tremendous potential and the development of which was of immense importance to the Allies.

Shoeing the Mustang

Orders for various Mustang types for the USAAF would begin in 1942, including this P-51 armed with four Hispano 20mm cannons. These orders were quickly overshadowed by developments to get the Packard engine into the aircraft. [Wikimedia]
Re-engining the Mustang was by no means an easy task, as the Merlin was considerably heavier than the Allison and required a larger cooling system. To achieve this, the radiator was reworked, with the oil cooler moved apart from the radiator matrix to a forward position, and the ducting of the entire scoop assembly being redesigned. Earlier aerodynamic and buffeting issues caused by the radiator intake were also resolved by moving the scoop out of the boundary layer under the fuselage. The resulting set up would also achieve the earlier described Meredith effect, which produced thrust that offset the drag caused by the scoop (Marshal & Ford 97, 219). Additionally, the carburetor’s intake duct was moved beneath the nose which also necessitated lowering the wing to accommodate the lower cowl.

In addition to higher cooling requirements, the new Merlin engine weighed 350lbs more than the Allison and would mount a larger, heavier propeller, which would represent a significant shift in weight. To compensate, 61lbs of ballast was added, the primary fuselage longerons were strengthened, and the wings were strengthened and moved lower and forward. These changes would also help to compensate for the stronger vortex generated by the propeller and the greater forces generated by the improved ailerons (Marshall & Ford 219). The new engine and the subsequent operations would also result in some yaw instability. Adding a fin ahead of the horizontal stabilizer seemed an adequate solution, but it would not be undertaken until far later.

While the testing for most of these modifications was done through a variety of converted air frames, the prototype that brought them all together was the XP-51B, which first flew on October 1, 1942. The importance placed on this aircraft was considerable, as several months prior, a large order for 1200 P-51A’s was placed by the US government on the provision that their production could be switched for P-51B’s, given advanced notice (Marshall & Ford 230).

The first of two XP-51B’s would be ready in October of 1942, however, a long and difficult development process would delay serial production until the summer of the following year.[Thisdayinaviation]
The XP-51B would prove promising but it was troubled by radiator issues which would remain with the aircraft through January of 1943. These were tracked down to a chemical reaction which was found to be degrading the coolant tubes, and was resolved by a lacquer liner. There were also air flow issues within the radiator, which were solved through moving its aftercooler core to improve airflow through the scoop. The prototype’s last major issue was the tendency for its air scoop to produce loud, and worrying, vibrations at high speed. Resolving the problem once again required them to change the geometry of the scoop (Marshall & Ford 258, 311). This was solved by the aforementioned modification that moved it out of the boundary layer below the wing, and further improved as the depth of the gutter was increased and the inlet size was reduced (Matthews 7).


Most of the issues with re-engining the P-51 involved its cooling systems and air scoop, which were revised several times. [NACA]
All of the production models of the Merlin powered P-51’s would fly with engines produced under license by Packard. It was a matter of good fortune that Packard was already engaged in the mass production of their version of the Merlin engine prior to the demand for the engine for the new Mustangs. Packard had built its first V-1650-1’s, a license built Merlin 28, in August of 1941 which were later destined for use in Canadian built Avro Lancasters, DeHavilland Mosquitos, and the updated Curtis Wright P-40F (Marshall & Ford 176). Changing production to suit the needs of the P-51B would however not be easy, and matters were made worse by a general strike at the main plant which, alongside slow development at Wright Field, made for considerable delays. Some of the supply issues would be addressed as the new Mustangs would receive the first priority in terms of supplies, superseding the P-40F and L, and denying its use on the P-38. However, beyond these were the predictable teething troubles, and combined with the less predictable hurdles, they saw widespread deployment of the P-51B delayed considerably. Packard would go on to supply North American with engines, however they would never fully be able to meet the massive demands of both the United States and Great Britain (Marshall & Ford 347).

My Kingdom for a Horse

While development on the Merlin powered P-51’s proceeded, the USAAF had formulated and launched a strategic bombing campaign dedicated to destroying industries vital to the German war effort. The theoretical foundations of this strategy had been set in the interwar era and were initially seen as a means to expand the Army Air Corps into a force with greater autonomy. Many early interwar theorists, such as Maj. Harold George, would describe a vague ‘economic web’ that could be destroyed and force an industrial and morale collapse, but in 1943 these theories were put to the test. The practical details of the campaign were laid out at the Allied conference at Casablanca. There a series of targets was decided upon, but later altered to a plan that favored targeting aircraft and submarine production, in addition to ball bearing plants (Overy 45, 305). However, the main concern for USAAF bombing operations was that thus far, all daylight strategic bombing campaigns had ended in failure after formations of unescorted bombers were shredded by fighters.

The USAAF bombing campaign against Germany began in earnest in early 1943, it was based on a number of untested theories which planners hoped would bring an early end to the war. [National Archives]
Since before the war, it was commonly believed among the Air Corps senior officers that a formation of well armed bombers was capable of defending itself from whatever threats it might face. This assertion would be disproven, as even the small raids against targets in France and the low countries sustained casualties that made consistent raids impossible. In early 1943, the next step of the campaign would be far more ambitious, moving on to targets deeper within Germany itself. The need for a long range escort fighter had already become apparent before this point, and work was underway to produce external fuel tanks for existing fighters, but the offensive would be continued without a fighter aircraft able to accompany raiders for the full duration of their missions.

Throughout the summer and autumn of 1943, the USAAF would launch numerous raids against targets in Western Germany, though the bombers could only be escorted over the low countries by P-47’s and P-38’s. It wasn’t long until these range limitations were understood, and soon after, exploited by the Luftwaffe. Wherever Luftwaffe fighters were untroubled by Allied fighters, they were free to make use of their most effective anti-bomber tactics.

Generalmajor Adolf Galland’s prescribed method of attack for single engine fighters was to make head on, or oblique, attacks from slightly above the bomber formation, carried out by at least a Schwarm, or two pairs of fighters (Marshall & Ford 267). This achieved two things, it increased the closure rate to reduce the likelihood of being hit by defensive gunners, and it was from this position that both the pilot and copilot of the bomber were most vulnerable. In the absence of escort fighters, Luftwaffe pilots would be able to regroup, fly ahead of the formation, climb, and repeat the attack. The lack of escort fighters also meant the Luftwaffe was safe to employ its two engined fighters against bomber formations, which with their heavier armaments, were much better equipped to bring down bombers. Over time their tactics grew even more complex as dedicated aircraft, typically Ju 88’s, were tasked with shadowing bomber formations to pass their altitude, course, and speed to flak and fighter control services.

Many Luftwaffe aircraft would be re-equipped to take on heavy bombers, like this Bf 109G-6 with its underwing 20mm gun pods. [Bundesarchiv]
Prior to the arrival of the P-51’s, the USAAF had two suitable fighters for the purposes of escorting bombers at high altitude, the P-38 and P-47. While they had the high altitude performance, they did not have the range to reach deep into the continent. The issue would be partially resolved through the addition of external fuel tanks, which had been discussed at a conference with the Material Division at Wright Field in March of 1942 (Ethel 51). Work however, was slow and the 108 and 75 gallon drop tanks were not delivered in large numbers until the end of summer, 1943.  These tanks would allow the shorter ranged P-47 to be able to cover bombers over their flight over the low countries, and the P-38, over the Rhineland. It should also be noted that the escort range was considerably lower than the maximum combat range of the aircraft, as the planes flew in a zig-zag pattern overhead so as not to out pace the bombers. Supplies of larger volume fuel tanks which would take the fighters further into German air space would not be available until the spring of the following year. External fuel tank development and procurement had been mismanaged by Army Air Force leadership who were still largely convinced that the bomber’s defensive capabilities were adequate. Had there been a greater supply, and larger volume tanks initially available, the P-47 and P-38 could have escorted bombers over most of Germany. To make matters worse, the P-38, which by then handled the most important leg of the trip, was troubled by a number of technical issues. While the P-38 possessed good high altitude performance, an exceptional climb rate, and a heavy armament, it was handicapped by a cockpit that pilot’s rated the worst of any US fighter in service and had flying characteristics that made it difficult for pilots to aggressively pursue Luftwaffe aircraft (Dean 164). The large, twin engine Lightning also had an unmistakable appearance, such that Luftwaffe pilots would almost always spot and identify the Allied plane before Lightning pilots could do likewise. With this benefit, Luftwaffe pilots were typically the ones who dictated the engagement, and would depart when conditions were unfavorable. On the defense they would have another advantage, both the Fw 190A and the Bf 109G were capable of out maneuvering the P-38 in high speed dives. The P-38 encountered severe compressibility issues at speeds significantly lower than those encountered on the two German fighters (Marshall & Ford 441). Thus, while the P-38 was capable of performing long range escort missions, its pilots would be forced to employ more conservative tactics than those used in the P-47.

By the start Autumn of 1943, USAAF planners were hoping to accelerate their progress on Operation Pointblank. This plan would see bombers raid targets that were vital to the German aviation industry in order to achieve air supremacy over Western Europe before an invasion of the continent. While losses for these raids were still extremely high, it was hoped that dispatching a larger force capable of inflicting serious damage would make it worth it. On August the 17th, the 8th Air Force prepared for its largest raid yet, with 376 B-17’s dispatched to attack the ball bearing works, at Schweinfurt, and a Messerschmitt factory, at Regensburg. Both of these facilities were located deep within Germany and most of the journey would see the B-17’s outside the area where they could be escorted. To compensate for this, the flight over Regensburg would continue over the Alps and into Allied controlled Tunisia. It was hoped that flight over the Alps would prove easy, and in the case of the Schweinfurt force, they believed that the German fighter squadrons would still be on the ground refueling after their first attacks while the bombers made their return. Both would be met with disaster as the Luftwaffe would hit both forces after their escort fighters turned for home, and the Luftwaffe fighters had taken to the air again as the Schweinfurt raiders made the return trip.

The bombers of the USAAF flew in staggered formations in order to maximize the the defensive capabilities of the aircraft. These tactics alone proved totally inadequate to protect bomber formations from fighters and were revised several times to compensate for flak. [National Archives]
Of the 376 bombers to leave England, 60 would be shot down, 176 were damaged, and 30 remained in North Africa where they awaited repairs at the overburdened facilities in Tunisia. Losses in combat and written off airframes amounted to 31% of the dispatched force; in contrast the Germans lost only 28 fighters (Overy 340, 341). Following the disaster, the 8th Air Force would carry out raids only where there was full escort cover and the next deep incursion into German airspace would only be conducted in the spring of the following year. The winter of 1943 would spell uncertainty for the campaign, as it was clear that for all intents and purposes, much of German industry lay beyond striking range. With this limitation threatening to seriously cut back the USAAF’s campaign, they would request that Lockheed, Republic, and North American increase the internal fuel capacity of their fighters, and hoped that a suitable long range escort would materialize.

Leaving the Stable

Col. Charles McCorkle, 15th AF with pilots. The P-51B proved the solution to the problems plaguing the ailing strategic air campaign. [National Archives]
As a result of the pressure to produce new, long range fighters for the escalating campaign in Europe, the first P-51B’s were produced before the prototype had gone through its testing and modification cycles. The first plane, a P-51B-1, was completed March 31, 1943 and would include several features that would later be found unsound on prototype. As a result, these initial planes would have to be altered accordingly and would have many parts that were non-interchangeable with later models (Marshall & Ford 316). In addition to reworking the air scoop and radiator, they would also have their ailerons modified, both to improve their effectiveness and to remove a steel diaphragm which would interfere with the plane’s magnetic compass. Most importantly, the decision was made that the aircraft would incorporate an additional 85 gallon fuselage fuel tank which would provide the aircraft with phenomenal range.

With this new aircraft, the USAAF would finally possess what they had been searching for. With the addition of the new internal fuel tank, the aircraft would be capable of deep incursions into German airspace, and it would deliver on what was promised back in the spring of 1942. They were excellent fighters, especially at high altitude. The early P-51B’s would use the Packard V-1650-3 engine, a license production of the British Merlin 61, which produced 1410 hp at 29,300 ft and 1630 hp at 16,400ft at War Emergency Power (P-51 operation manual 31). This engine would later be replaced with the Packard V-1650-7 in later models of the aircraft, which was geared for better performance at medium altitude. These engines, combined with the low drag fuselage and laminar designed wings would provide the aircraft with a superb climb rate, a high top speed at altitude, and exceptional high speed maneuverability.

While the aircraft had taken a largely completed form with the P-51B-5 and P-51C-1, it would be continuously modified in the field and on the production line, throughout its service with the air force. The most notable of these changes were the additions of a fuselage tank, booster motors for its ammunition belts, a vertical fin extension, and field retrofits for a perspex canopy dubbed the Malcom Hood. However, only the 85 gallon fuel tank would be a universal addition.

The fuselage tank would enable the P-51B’s to reach much of central Europe from England, but it was not present in the first deliveries of the aircraft, as was the case with the 59 P-51B’s active in England at the end of November 1943. The installation kits were first sent out in September of 1943, and the tank was later incorporated into the production run with the first long range P-51B being accepted by the Army in December of the same year (Marshall & Ford 393, 407).

The next addition to the aircraft was intended to solve a major issue with the plane’s machine guns, which were found to be prone to jamming when the pilot pulled turns of over 1g. This issue was a result of the canted position of the guns in the wings which put stress on the ammunition belts. The ideal solution was to reposition the guns, but seeing as that would necessitate a considerable redesign, engineers would instead work in a stop gap measure in the form of boost motors for the ammunition belts. These were issued as kits like the fuel tank, though unlike those for the fuselage fuel tank, they were issued in more limited numbers and the issue persisted well into 1944 (Ethell 64).

The Mustang had long had a tendency to yaw in the opposite direction of a roll, which affected its handling since its earliest models, and this was made significantly worse when fuel was carried in the fuselage tank. Despite the problem being an evident and considerable inconvenience, its solution wouldn’t materialize until much later. Eventually, it was decided to fit the aircraft with a fin extending from its vertical stabilizer, along with adding reverse rudder boost tabs. However, these kits arrived very late, having begun production in April of 1944, and later incorporated into the design of late P-51C’s and the subsequent P-51D (Marshall & Ford 306).

The Malcom Hood provided far better visibility than the earlier ‘birdcage’, and was added to a number of P-51B’s based in Northern Europe. [National Archive]
Many long standing issues revolved around the ‘birdcage’ canopy of P-51 since the aircraft’s inception, and as was the case with the engine, an improvement was found in British service. With the RAF, many Mustangs received a new frameless bubble canopy. This canopy vastly improved visibility, especially to the rear of the aircraft, which was virtually non-existent from within the birdcage, and it could be drawn back on landing and take-off. Dubbed ‘Malcom Hoods’ after their manufacturer, a plexiglas works named Robert Malcom Ltd. they were subsequently sought after by the USAAF for use with their P-51’s in Europe.

Breaking the Stalemate

The new P-51B’s would make their first major debut with the 8th Air Force in early 1944, though the introduction was not as smooth as had been hoped. Squadrons reported a number of issues with the new aircraft, which included high altitude fuel transfer failures with external tanks, glycol reserve tanks that leaked and froze, radiator corrosion and coolant leaks, radios and spark plugs failing, and excessive oil loss (Marshall & Ford 425). However the USAAF hadn’t the time to immediately resolve these teething issues, and with these problems passed along to the manufacturer and Air Force maintenance services, the P-51’s would soon play a key role in the escalating bomber offensive.

Through the winter of 1943, both the day and night bombing campaigns were facing withering losses which spelled serious trouble for maintaining the pace of operations over Europe. With less than one thousand bombers stationed in England, the USAAF would lose 200 in September alone (Douglas 326). In the face of these losses, the Combined Bomber Offensive was failing to carry out the Pointblank directive, which aimed to cripple the Luftwaffe before an invasion of Europe was conducted. During this period the Luftwaffe had actually built up the strength of its fighter force and had reorganized and improved its defenses into a centralized command structure. To make matters worse, the head of RAF’s Bomber Command, Arthur Harris, would ignore orders to attack German industries involved in aircraft production. Instead, he would order Bomber Command to continue to carry out an ineffective area bombing campaign of Germany’s cities believing it would bring an end to the war without the need for an invasion (Overy 343, 344). It was under these bleak circumstances that the US’s Eighth and Fifteenth Airforces were tasked to cripple the Luftwaffe and establish air superiority over much of Europe before the invasion, now only a few months away. However, they would soon see a change in leadership and the delivery of new equipment that would put them on the path to controlling the skies over Europe.

Escort fighters typically flew a few thousand feet above their charges when they weren’t independently seeking the enemy. They weaved back and forth over the bombers in order to not speed past them. Here a flight of four P-51’s flies overhead at roughly 30,000 ft. This tactic declined in use when the relay system came to prominence. [National Archives]
In December of 1943, the USAAF established a joint strategic air command to consolidate their bomber forces over both the European and Mediterranean theaters, and drive them towards a unified objective. With Gen. Spaatz in command of all strategic bomber forces, and Maj. Gen. James Doolittle in command of the Eighth Airforce in England, the USAAF would now have clear strategic direction, and more aggressive leadership. Doolittle would take a pivotal role in revising the existing strategy into one which proved instrumental in undermining, and dismantling the Luftwaffe in the coming weeks. Crucially, he recognized the inadequacy in trying to undermine the Luftwaffe’s fighter strength solely through targeting the production of new aircraft. To hold to this existing, overly conservative strategy was hopeless, and the invasion of France was scheduled for five months after he took office. Targeting the factories alone wasn’t enough, and thus Doolittle would give the order for returning escort fighters to perform fighter sweeps and seek out enemy planes in the air and on the ground (Overy 361). Among the first and most important moves was to create a more effective relay system for the fighters, further increasing the time they could spend over enemy territory.

By the start of 1944, Maj. Gen. Kepner, 8th Air Force, would also play a major role in implementing this new strategy, as he officially untethered the Eighth’s fighters from the bombers and allowed them to seek out the enemy at their discretion. The P-51 would play a pivotal role, as its excellent high altitude performance and range meant it was able to take up the last position of the fighter relay, and was more than a match for whatever it found. Beyond the existing penetration, target, and withdrawal relay positions, the P-51 was also able to take up a fourth mission. These units would perform sweeps 50 to 70 miles ahead of the bomber formation and attack German fighters as they were climbing, assembling, or transiting towards the bomber formation. Their efforts were greatly aided by British signals intelligence services that provided the assembly points for the Luftwaffe’s fighter groups (Marshall & Ford 425, 425; Overy 362).

This change in tactics would have immediate and profound impacts as they began to be widely implemented in February and March of 1944. The first major achievement of the new strategy were the widespread losses inflicted on the twin engined fighter forces, which had earlier proven themselves as potent anti-bomber weapons. Against the new long range fighters, they were almost defenseless, and were withdrawn in March (Overy 366). Similar effects were felt throughout the Luftwaffe’s fighter forces, which thanks to the new P-51’s, were left without any safe haven. Whenever the bombers were over Germany, their escort fighters could make their appearance. While the new strategy often meant that the bomber formations were often less protected, this was counterbalanced in that it placed the German fighters on a defensive footing. The days of Luftwaffe fighters leisurely climbing alongside a formation before diving at it head on were over, now whenever they reached a formation they were forced to conduct hit and run attacks, or face off against the escorts.

Luftwaffe attrition escalated as airfields that were once ignored were now periodically harassed by fighters that attacked transiting and grounded aircraft. Doolittle did all he could to promote these attacks, and would allow for the destruction of aircraft on the ground to count towards a pilot’s ace status (Marshall & Ford 423). These attacks would prove costly to the USAAF, but well worth it as Luftwaffe operational losses for all aircraft increased sharply and it robbed them of the ability to train new pilots in secure airspace. This shift in strategy and subsequent success would prove instrumental to the USAAF in the following months, as their responsibilities were soon to broaden when the Allies landed in France.

When equipped with external fuel tanks, the P-51B could operate over any part of Germany. This proved disastrous for the Luftwaffe as transiting aircraft and those on the ground were now vulnerable, no matter how far they were from Allied air bases. [National Archive]
While the Eight and Fifteenth air forces were still occupied with the task of destroying the Luftwaffe in the air and on the ground, they would soon be given additional missions. The most unexpected of which came in the form of Operation Crossbow, which called upon the Eighth Air Force to disrupt Germany’s use of the new V-1 bomb from coastal bases. Then came the task long awaited, which called upon the Eighth to begin the preparations for Operation Overlord. To meet these new objectives, the Pointblank raids were accelerated, culminating in ‘Big Week’ in February of 1944.

Between the 19th and the 26th, the Eighth and Fifteenth air forces would fly roughly 6,200 sorties against 18 aircraft assembly plants and two ball bearings plants, at a loss of 247 bombers and 28 fighters. Undoubtedly steep, but sustainable in comparison to the Luftwaffe which lost roughly one third of its single engine fighters (Overy 369). The success of the raids themselves was difficult to judge, as fighter production still increased, though at a significantly reduced rate which saw a shortfall of roughly 38.5 percent (Overy 370). During these operations the P-51 would provide the USAAF deep penetration cover and perform strafing attacks against German airfields. However, there weren’t enough long range escorts for full coverage until the summer of 1944. The situation was further complicated when all P-51B’s were grounded between the 10th through the 15th of March in order to address structural issues with the aircraft’s engine mounts, wings, and tail. These were subsequently resolved by replacing the retaining bolts for the engine, reinforcing the tail empennage and ammunition doors, and installing landing gear locks to prevent their uncontrolled release at high speed (Marshall & Ford 442, 446). These issues would however not present a long term obstacle during the early months of 1944 as the tempo of operations and list of targets grew in the following months.

With the major push against the German aviation industry mostly over, the USAAF would soon set its sights on two major targets, rail communications across much of Northwestern Europe, and Germany’s oil industries. The first was an immediate necessity for the success of Operation Overlord, crippling German strategic mobility was essential for an invasion which would require considerable time after the first landings to build up a force on the continent. The formalities were worked out in March when the Transportation Plan was decided upon. It would fortunately have the support of RAF Bomber Command, as Harris’s evident failure to end the war on his terms would see him temporarily divert his force into supporting the preparations for the invasion of France. The subsequent offensive against fuel production would start far less formally. Spaatz was convinced of its necessity, but due to the months it would need to take effect, he was at first unable to convince his superiors to divert resources to it. However, in a matter of weeks, he was able to argue for its necessity under the Pointblank Directive and was then allowed to conduct attacks against Germany’s synthetic fuel industry whenever resources permitted (Overy 371).

Between the now crippling fuel shortage and marauding allied fighters, the Luftwaffe soon found themselves completely overwhelmed by the autumn of 1944. Here a P-51 lines up on an He 177 heavy bomber, as the one beside it continues to burn. [National Archives]
With these new policies in place, the Luftwaffe would be thoroughly disrupted as a result of Spaatz’s strategy, and Doolittle and Kepner’s tactics. The USAAF would end up inflicting punishing losses on the Luftwaffe in the air, disrupting the manufacturing of new aircraft, and eventually causing chronic fuel shortages that severely limited their ability to conduct large scale operations of any kind. In this, the P-51 would prove essential with its exceptional high altitude performance, and its endurance that could take it anywhere over Germany.

In many ways, the bombing of factories alone was a largely ineffective means of inflicting serious damage to the German war economy, as many industries proved to be exceedingly resilient. Fighter production proved a particularly difficult target, as apart from the later targeted aero engine industry, production and final assembly plants could be dispersed and were largely safe from raiders. When fighter production was further streamlined and resources were diverted to support it, Germany would end up vastly expanding fighter production during the period in which those industries were the most frequently raided (Zeitlin 59). This was, however, was achieved only by reducing the rate of modifications and improvements, and transferring resources away from the production of bombers. In comparison, the later targeting of fuel production and rail transportation proved key, as the inability to reliably move material by rail combined with chronic fuel shortages proved a fatal military and economic obstacle. As a result, establishing air supremacy over Western Europe before Operation Overlord was as much an achievement of long range fighter operations as it was of the bombers. The Luftwaffe could sustain itself when aircraft deliveries did not meet expectations, but it quickly found itself struggling when it lost scores of pilots and found itself hard pressed to train new ones once they had lost control of the skies over Germany.

Pre-war military theorists envisioned fleets of bombers destroying vital war industries with the near pin-point accuracy they achieved in controlled tests. The reality of the campaign revealed this as hopelessly optimistic when even the most accurate raids resulted in large amounts of collateral damage. [National Archives]
In the end it must also be said that the civilian costs of the raids were steep, and while the Eight and Fifteenth Airforces were not involved in a campaign directed against the civilian populace, as was the case with Bomber Command and the USAAF elsewhere, the technical limitations of the time meant that bombs frequently fell on civilian areas. Even under ideal circumstances, the dimensions of a bomber formation were larger than their targets and it was physically impossible to strike factories, railyards, and refineries without causing significant damage to the surrounding area. The realities of the campaign would also prove worse than predicted. Targets were frequently obscured by bad weather and smoke generators, and formations typically took heavy anti-aircraft fire on the approach. As a result, bombs were often released by the best estimate from the bomb sight or at the direction of a ground mapping radar system (Overy 347). Even outside of Germany, the civilian costs of these operations were heavy as the Allied air forces carried out the transportation plan. In France alone, between March and June of 1944, French officials placed the figure of civilians killed by Allied bombing at 25,266 (Overy 574).

The 4th Fighter Group ‘Debden Eagles’

When the US entered the Second World War, few American airmen had any combat experience, with the notable exceptions being volunteer airmen in service with foreign armies. The Debden Eagles were one such group, having volunteered to serve with the RAF and entered service in late 1940 and 1941. While they were among the few Americans fighting against Nazi Germany at the time, they had garnered a somewhat unfortunate reputation as glory-seekers and primadonnas thanks to their unique position (Bucholtz 6). Their tendency of excessive overclaiming of victories during this period would prove particularly irritating to their superiors. With the US entry into the war, the Eagle squadrons, and their Supermarine Spitfires, were subsequently integrated into the USAAF.

Capt. Donald Willis, an Eagle Squadron pilot alongside a Spitfire Mk V, late 1943. [National Archives]
The RAF’s 70th, 121, and 133 Eagle Squadrons would become the 334th, 335th, and 336th Squadrons of the 4th Fighter Group on the 12th of September 1942. These units flew Spitfire Mk IX’s and within the month were supporting the nascent bomber offensive which was targeting installations in France. The start of this effort went poorly, when only one aircraft out of a twelve plane flight returned, the rest having been lost to enemy fighters, harsh weather conditions, or having run out of fuel in the short range fighter. Thankfully for the Group, this would be their worst day of the war. Despite this setback, the unit saw its first major mission carried out on the 20th of October in the Calais area escorting B-17’s carrying out a high altitude raid. This would be the first major bomber operation carried out under escort and was met with success. Their Spitfires would prove a very capable fighter aircraft, but their short range rendered them unable to conduct escort missions far beyond the English Channel. In any case, this wouldn’t prove much of an issue, as for the rest of the year as they would mostly conduct fighter sweeps across the low countries and provide convoy cover (Bucholtz 9). However, with the changing of the year, the 4th would exchange their venerable Spitfires for new P-47’s.

The 4th FG flew their Spitfires in combat for the last time on April 1st, 1943, after which they completed the full transition to P-47C’s. This change was not viewed favorably, as most of the unit’s pilots disliked the considerably heavier Thunderbolt (Marshall & Ford 340). The changeover had little initial impact on operations, and the squadron was largely involved in the same missions as before. However, the group would later accompany bombers on deeper raids into Europe thanks to newly issued external fuel tanks for their P-47’s. They would use these new 200 gallon fuel tanks on an escort mission into Ghent on July 25th and soon after their first foray into Germany airspace over Westhoff-Emmerich. It should be noted that these fuel tanks were a rare piece of equipment at the time and the 4th only had them thanks to the efforts of Lt. Col. Cass Hough of the 8th Fighter Command’s technical section. They were, unfortunately, as troublesome as they were vital, often failing to transfer fuel above 20,000, and were later withdrawn as British made paper 108 gallon tanks became more available (Marshall & Ford 411).

Despite their complaints, the 4th FG’s veteran pilots would master their new planes and had put them to good use. In a battle defending a formation of B-17’s over the city of Utrecht, the 4th FG was credited for the destruction of nine enemy aircraft at the cost of one of their own, with the pilot having bailed out over the occupied Netherlands (Bucholtz 16). With their P-47s, the 4th would take up an important supporting role in the escalating bombing offensive, one which saw their longer ranged P-47s making more flights into the German frontier. This tempo and the 4th’s change in command under the more aggressive Lt. Col. Don Blakeslee would see the unit become among the most successful in the entire USAAF.

Col. James Matthew Blakeslee would lead the 4th FG from January to November 1944, after which he remained on the ground after several high profile pilots of the USAAF had been lost in a short period of time. He is pictured here receiving the Distinguished Service Cross from Supreme Allied Commander in Europe, Dwight Eisenhower. [National Archives]
Lt. Col. Blakeslee was made C.O. of the 4th with the turn of the year, and in addition to bringing new, more aggressive tactics to the table, he would work to ensure his unit was re-equipped with the new P-51. Blakelsee would meet personally with General William Kepner and argue that his squadron would be the best candidate for refamiliarization with the new plane as their experience with the similarly-engined Spitfire would make for an easier transition. Kepner was convinced, and subsequently put the 4th FG at the top of the list for P-51’s. The schedule for the transition was harsh as they continued to fly combat missions in their P-47’s while also familiarizing themselves with the new aircraft. The process was time consuming and they would not make their operational debut with their new planes until February 28, 1944 (Marshall & Ford 432). These Mustangs would nearly double the combat range of the unit, and the pilots favored them over their older P-47’s, but they experienced a variety of harsh teething issues and mechanical failures.

While the conversion was taking place, the 4th would be committed to Doolittle’s more aggressive strategy against the Luftwaffe, with the aim to achieve aerial supremacy over Western Europe before the invasion of France. As such their independent actions increased, and on January 31, 1944, they would join the 355th FG in bombing the Luftwaffe’s airfield at Gilze-Rijen (Marshall & Ford 425). In many ways this mission bore some similarity to the fighter sweeps they had conducted since they had flown with the RAF, but it would mark a first in that direct assaults on Luftwaffe airfields would then become more commonplace. Among the last major actions the unit would perform with its P-47s was its support of ‘Big Week’.

Their first combat mission in the new planes was fairly uneventful, on February 28, when flying as escorts for a formation of bombers attacking a V-1 launch site they encountered no enemy aircraft but strafed a Ju 88 on their way home. They would claim their first aerial kills two days later during a bomber withdrawal support mission near Frankfurt where they claimed two enemy fighters (Bucholtz 38). The following day the unit would help achieve a major milestone, the first fighter escort operation to Berlin and back. The operation would prove anything but easy, as deteriorating weather conditions saw most of the aircraft involved turn back. However, elements of the 3rd Bomb Division would press on, supported by the 4th, 55th, 354, and 363rd FG’s. The 4th would engage a formation of roughly 60 Fw 190’s and Bf 110’s northeast of Wittenberg in the day’s first encounter with the enemy. They claimed five victories but suffered one loss from enemy fire, and another as a result of a radio failure which made navigation across a storm in the English channel impossible. The pilot was later forced to ditch his aircraft in France after a failed attempt to reach neutral Spain (Marshall & Ford 439, Bucholtz 39).

Capt. Don Salvatore Gentile was among the leading aces in the 4th FG. He was credited with 21 aerial and 6 ground victories, though his combat service ended after a botched aerobatics stunt in front of assembled members of the press. He was grounded and went on a tour to raise war bonds, later becoming a test pilot. [National Archives]
Perhaps the most exciting encounter that day was experienced by Capt. Don Gentile and Lt. John Godfrey, both aces in the 4th. The two pilots were unable to join the rest of their flight as a result of extremely poor weather, but proceeded with their mission regardless. En route the weather would clear, and reveal a flight of roughly 50 Do 217 night fighters, pressed into service as daylight bomber destroyers, and dozens of Fw 190’s which were preparing to attack a nearby formation of USAAF bombers. The pair would decide to attack, in order to disrupt the enemy formation and prevent them from engaging the nearby bombers from an advantageous position. Gentile and Godfrey dove on the night fighters, damaging one and sending the group diving in an effort to escape. The engagement turned into utter chaos as the single-engined fighters joined in. In the confusion, the pair of aces would claim one enemy aircraft in a series of defensive fights that eventually saw them make their escape through the clouds. Flying on instruments and practically lost, they made their way back to England by their intuition, landing at RAF Hurn (Bucholtz 40).

The unit would return to Berlin on March 6 in support of a massive 8th Air Force operation. Favorable weather conditions would allow the 8th to dispatch a force of 730 bombers against a series of targets in and around the German capital, where they would meet the Luftwaffe in the largest air battle of the war up to that point. The 4th, led by Col. Blakeslee, would be tasked with escorting the bombers, which would prove a difficult undertaking, with the sheer number of opponents forcing the group to disperse into individual flights and sections to expand their coverage. The unit would be credited for the destruction of 15 enemy aircraft of the 45 claimed by P-51’s that day, in exchange for five losses. In comparison, P-47 units were credited with 37 kills for 5 losses, and P-38 units brought down three units at the cost of three of their own. It should also be noted the P-38’s comprised the minority of the fighters, while there were roughly twice as many P-47’s as there were P-51s. The USAAF would claim a total of 83 ‘confirmed’ enemy aircraft with the Luftwaffe having recorded the loss of 75 fighters (Marshall & Ford 439; Bucholtz 43, 45). The majority of these kills were twin engine and night fighters pressed into daylight service. This engagement, while not representing a distinct turning point, did demonstrate a noticeable shift in the war over Germany. Of the 672 bombers that proceeded with the mission, 69 failed to return, and 6 were written off. These were certainly heavy losses, but were a fraction of the nightmare that the Allies were facing in the summer and autumn of the previous year. Beyond that, Luftwaffe losses were mounting both in the sky and on the ground, and the use of its heavier, twin engined bomber destroyers had become untenable in the face of agile new opponents.

D-Day

During the first day of Operation Overlord, most fighter units were dedicated to countering a Luftwaffe response that never came. Several would go on to attack inland targets. [National Archives]
Over the coming weeks the 4th would continue to support the bombing campaign, but in June of 1944 they would participate in something far more decisive. The group would be among the many fighter units providing top cover for the invasion of Normandy. Throughout D-Day, each of the unit’s three squadrons would operate independently and continuously until nightfall. The day began with the 334th and 335th squadrons undertaking an offensive patrol under the command of the unit’s C.O., Col. Blakeslee, between 03:20 and 09:45 over Rouen, France. The patrol found no enemy fighters and sought out targets of opportunity, in their case a pair of locomotives that they strafed with their machine guns. Their only loss was 1st. Lt. Fraser, who had lost contact with the rest of the squadron and was subsequently downed by German fighters and taken prisoner. The 336th would sortie at 06:42 to provide cover for warships shelling the landing areas, which proved uneventful (Bucholtz 84).

At 11:20, the 334th would sortie again to Rouen with one section carrying bombs. They would attack a troop train to poor effect, though an encounter with a flight of 10 Fw-190 near their airfield at Evreux proved more successful. In the ensuing battle the 334th was credited with the destruction of four enemy fighters, with the only damaged P-51 making it back home. While this confrontation was happening, the 335th had attacked the marshaling yards at Fleury. The 336th would fly for the last time that day at 13:35 conducting a fighter bomber sweep near Evraux. They would find no targets and would lose an aircraft to ground fire, with 1st Lt. Freiderick being taken as a PoW. The last mission of the day would see the 334th and 335th conduct attacks against a radar station and a road convoy near Rouen. While successful in their mission, they incurred heavy losses when elements of the unit were attacked by around 15 fighters belonging to JG 2 and JG 26 as the US fighters attacked infantry positions.

Capt. Winslow Sobanski was a Polish infantryman at the outbreak of the war, eventually finding his way to the US where he then joined one of the Eagle Squadrons. He was among those killed in action during the group’s last sortie on D-Day. Pictured here in a P-47. [National Archives]
The day would prove exhausting, with pilots flying up to three missions from dawn to dusk. Between flights most of the 4th’s pilot’s would rest, usually either having coffee or trying to get some sleep in before their next mission. The different squadrons would also find themselves having vastly different experiences, with the 336th having spent most of the day covering the invasion force which the Luftwaffe hadn’t the strength to attack, and taking part in a fighter bomber sweep that found no worthwhile targets and saw one aircraft lost to flak. In comparison, the 334th and 335th spent the entire day conducting offensive sweeps which claimed a number of targets, but also saw them sustain higher casualties than any of the other US fighter squadrons over Normandy that day with ten fighters lost (Bucholtz 82, 83).

Shuttle Mission to VE-Day

Following the success of the landings, and subsequent breakout in Normandy, many of the USAAF fighter units would take on tactical missions in support of the armies in Western Europe, in addition to the ongoing strategic air campaign. However, some P-51 units were selected to participate in an escort mission in which the bombers would land at prepared airfields in the Soviet Union instead of returning to their home bases. A 45 aircraft detachment of fighters from the 4th would depart for the Soviet Union on June 20th. The mission would see them join a force of 1,000 bombers as they attacked targets in the Rhineland, and then on to Piryatin, Ukraine some seven hours away. 45 Mustangs of the 4th would make the trip, encountering some 25 enemy fighters over Siedlice, downing two, but losing one of their own. All but one of the remaining planes landed at their intended destination, with one 2nd Lt. Hofer being forced to land at Kiev after running low on fuel after pursuing enemy fighters (Bucholtz 88). However, unbeknownst to the assembled American aircraft, the formation had been trailed by a Ju 88. Soon after, a well coordinated attack by the Luftwaffe using its He 177 heavy bombers saw many of the US bombers hit, though their P-51’s were unscathed.

The P-51’s were subsequently dispersed and flew a variety of missions in the following weeks which brought them over Central Europe and the Mediterranean. They soon flew an escort mission against an oil refinery in Drohobycz, Poland on the 26th. The return leg of the mission took them to Lucera, Italy where they would support the bombing operations of the 15th Air Force. The largest of these missions would take them over Budapest to perform a fighter sweep ahead of the strike force. There they encountered 80 German and 18 Hungarian Bf 109G’s and a massive dogfight ensued. In the battle the 4th would claim eight Axis fighters at the cost of four of their own. This included 2nd Lt. Hofer who had died during a strafing attack against an airfield. (Bucholtz 89). The unit would be led back to England on the 3rd of July.

American and Soviet personnel during Operation Frantic. [National Archives]
Beyond Operation Frantic the 4th settled back into the ‘usual’ operations they’d had since most of the group had left for the Soviet Union. They continued to fly deep penetration and escort missions over Germany, though by the end of the summer, Luftwaffe activity in the air had been considerably reduced. The savage war of attrition over Germany had been decisively won by the USAAF, as the Luftwaffe began to feel ever more crippling shortages of experienced pilots and fuel. Ironically, the Luftwaffe’s supplies of fighter aircraft were secure, though transporting them to airfields would prove ever more troublesome through the remainder of the war. While they had the aircraft, a subsequent USAAF campaign against rail communications across Germany would make overland transportation difficult, and ever more frequent fighter sweeps made transiting by air a very dangerous prospect.

For the remainder of the war the 4th FG remained committed to supporting the strategic bombing campaign, especially as it pertained to offensive fighter sweeps and attacks against Luftwaffe airfields. Their last victory of the war was a probable destruction of an Me 262 that was damaged over the Prague/Ruzyne airfield, with the group credited for 1,058.5 total victories against enemy aircraft, both in the air and on the ground (Bucholtz 120). They would end the war among the most successful Fighter Groups in the USAAF, having come a long way from the overly boastful volunteers that had flown against the Luftwaffe before any other Americans.

The 99th Fighter Squadron ‘The Tuskegee Airmen’

As black aviators, the men of the Tuskegee-trained squadrons would face unique challenges, having to face prejudice from their own countrymen who sought to deny them the opportunity to fight. They were initially excluded from many of the pre-war programs that turned out many of the pilots who later joined the ranks of the USAAF and US Navy. Many who ran these programs espoused the belief that they were incapable of the judgment needed for leadership, and that they had lacked ‘the proper reflexes to make a first class fighter pilot’ in the words of General Edwin J. House (Moye 102).

Their chance came with the Civilian Pilot training program in 1939, having been excluded from the program the previous year. The program was extended to a series of predominantly black colleges and universities, with the most critical being the Tuskegee Institute in Alabama. The university would build a fledgling airfield that eventually grew into an Army Air Corps training base, which proved controversial even among hopeful applicants, as in their eyes they were clearly still segregated from the rest of the Army. While the controversies flowed in the small Alabama town, the Air Corps moved to create the first black pursuit squadron, the 99th.

Col. Benjamin O. Davis would lead the 99th fighter squadron and the later 332nd Fighter group. He would go on to become a Brig. General in the newly formed United States Air Force after the war. [San Diego Air and Space Museum]
The first cadets of the 99th would graduate March 7, 1942 under the command of Capt. Benjamin O. Davis. The squadron would subsequently fly within the US before its transfer to the Mediterranean in late March 1943, equipped with new P-40L’s (Moye 99). They occupied a former Luftwaffe airfield in Morocco and were to be attached to the 33rd Fighter Group after they had gotten some experience in theater. In May, the squadron would be deemed ready for service and would move to a field in Tunisia. They would see success there, but the leader of their fighter group, Col. William Moymer was immediately hostile to their presence. He failed to return the salutes of the 99th’s officers and he placed the squadron on patrol duties over secure air space. He would then openly criticize them for being ‘unaggressive’ for failing to claim victories over territory where they were unlikely to encounter enemy aircraft (Bucholtz 18, 19; Moye 101). In spite of this, the unit pushed on and would aid in the preparations for the invasion of Sicily.

The 99th’s first combat missions were fighter sweeps against enemy positions in Southern Italy, their first target being a German airfield on the island of Pantelleria on June 2, 1943. The airbase would be the site of many more attacks, including the unit’s first encounter with enemy fighters. On June 9th, six P-40’s from the 99th Squadron accompanied A-20’s to the airfield, encountering four enemy fighters. In the ensuing fight they successfully drove off the enemy aircraft, and damaged one, taking no losses of their own. A further effort was made to intercept a flight of Ju 88’s at high altitude but were unable to, as their P-40’s had their oxygen systems removed to save weight for the low altitude mission (Bucholtz 21). The pilots of the 99th were particularly enthused that in their first encounter with the enemy, they had managed to complete their mission and all returned home safely.

While they would eventually be known for their iconic red tailed P-51’s, members of the Tuskegee fighter squadrons would fly the P-40L, P-39Q, and P-47D before they were issued Mustangs. [National Archives]
The squadron would be redeployed days later, partially a result of Moymer who sought to see the squadron reduced to coastal patrol duties. Instead, the 99th was transferred to the 79th Fighter Group, who’s commander, Col. Earl E. Bates, did his best to integrate the unit into the group. While they remained formally segregated, they enjoyed a far more open and professional environment than what they endured with the 33rd (Moye 103). Their first mission with the unit was on July 2 and saw them escort a flight of 16 B-25’s to their target, a German airfield in Castelvetrano, Italy. It would prove less than ideal when the B-25’s failed to line up with their target on the initial approach and had to repeat the attack, giving Axis fighters stationed nearby the time they needed to scramble. Two of the 99th’s pilots were lost in the first pass from the German fighters, but the remaining members soon regained control of the situation. In the ensuing confrontation with enemy Fw 190’s, Bf 109’s, and a Macchi 202, the 99th would claim one confirmed destruction, one probable, and two damaged aircraft. Though perhaps most importantly, none of the B-25’s they were escorting came to harm (Bucholtz 21, 22).

The coming weeks saw them mostly fly ground attack missions in support of the ongoing invasion of Italy, and met very few enemy aircraft for the remainder of the year. It was during this time that they also discovered that the Tuskegee training center wasn’t large enough to supply a sufficient number pilots to the squadron, while also supporting the construction of three additional squadrons. Their pilots resultantly flew an abnormally high number of missions due to being short handed (Bucholtz 25). This period also saw them defeat a great deal of the unfair criticism leveled against them and had largely cemented a favorable reputation within the Army Air Force. Among the most notable victories on that front was an article in Time, which had previously published an article based on Moymer’s alleged grievances with the squadron. Maj. Roberts of the 99th would be quoted “people assumed we were not producing because we were negroes…but now that we have produced, things have changed.” The 99th had also succeeded in convincing most of the 79th FG of their worth, and had garnered a great deal of respect as they moved into 1944. Many white pilots of the 79th disobeyed an order from the commander of the Air Force commander in the MTO, and held a desegregated dinner party to celebrate the anniversary of the 99th’s combat debut (Moye 104, 105).

Forming the 332nd Fighter Group

While 99th gained valuable experience over the Mediterranean, they began to rotate pilots out to train the next pursuit squadrons to form a segregated fighter group. These squadrons were the 100th, 301st, and 302nd, all of which would be formed at Selfridge Field, Michigan. Selfridge would prove a particularly dreadful post for these men, as it was here that they would face intense discrimination both by the local populace and base staff, while being a stone’s throw from the racial powder keg of Detroit. However, this would not remain their home for long, and they would soon depart for their operational assignments by the end of the year. They would join the 99th in the Mediterranean Theater of Operations in January of 1944, being equipped with a set of used P-39s. These aircraft would prove troublesome in service due to their age and condition, and as such numerous accidental losses followed, so by the early summer of 1944, Col. Davis had managed the acquisition of new P-47Ds. However, the unit would soon transition again to the newer P-51 soon after the 99th joined the rest of the fighter group in July, something the group’s veterans would resent as they felt they had been segregated again after finding acceptance within the 79th FG.

Capt. Andrew Turner aboard a P-51. The group’s transition to this aircraft vastly expanded the range and variety of operations across the Mediterranean and Central Europe. [National Archives]
The group would fully transition to Mustangs by July of 1944, and would be reassigned to the 15th Air Force where they would support long range bombing operations. Their first mission in their new planes was on July 4th, where they took 40 aircraft to to escort two bomber wings, but they would encounter only a pair of Bf 109’s that made no attempt to attack the allied aircraft . Beyond this, their pace of escort missions rose and they would take part in supporting raids against Axis positions in Northern Italy and Southern France. Soon after, they would provide support for the amphibious invasion of Southern France. On August 12, All four of the 332nd’s squadrons were given specific targets, with the 99th striking radar stations in Montpelier and Sete, the 302nd attacking radar stations in Narbonne and Leucate, the 100th attacked the radar stations near Marseilles and Cape Couronne, and the 301st attacked four targets around Toulon. At the loss of three pilots, one captured and two killed, all of the targeted radar stations sustained considerable damage .

The remainder of the war saw the 332nd fly a considerable number of escort missions, including an earlier attack against the Ploesti oil fields in Romania on July 13th, 1944. It was during that mission that they had begun to cement their status as one of the most reliable escort units in the USAAF, after they dispersed a flight of eight German fighters that had attacked bombers of the 55th Bomb Wing. Their C.O., Col. Davis maintained an unwavering directive to his unit, on escort missions they were never to abandon their bombers. This didn’t sit well with some but it was accepted, in part because many felt that a failure to protect the bombers would come down harder on them than the other squadrons (Bucholtz 51, 105; Moye 102). As such, their record for defending bombers was exemplary, having lost only 27 bombers to enemy fighters from June of 1944 to April 1945. It should also be noted that 14 of these losses occurred during a single day when a failure in mission planning resulted in the bombers and their escorts failing to meet at the proper time. As the target that day was the Luftwaffe air base at Memmingen, Germany, losses were correspondingly high (Bucholtz 53, Haulman 2). This places the remaining 13 bomber losses among the other 178 escort missions they performed over ten months. This policy would however, result in the squadron having the lowest aircraft kill to loss ratio of any other P-51 squadron in the theater, however, they would still consistently outscore all of the veteran P-38 squadrons in the Mediterranean (Marshal & Ford 477).

Among their most impressive escort missions was in support of a bombing raid against the Daimler-Benz tank assembly plant in Berlin, on March 24, 1945. From the 332nd’s base in Ramitelli Italy, this was a 1600 mile round trip, the longest mission ever conducted by the 15th Air Force. 59 Mustangs of the 332nd would leave their base at 11:45 under the command of Col. Davis, though he would soon return after experiencing engine trouble and left the squadron in the command of Capt. Edwin Thomas. They would encounter some two dozen enemy fighters outside of the German capital, including a number of Me 262s. The jets would initially prove difficult to catch, and the aircraft, belonging to JG 7, would at first disengage from the bombers whenever the escorts drew close. However, several of the jets would later press their attack on the formation. In the ensuing battle 1st Lt. Earl R. Lane, Flt. Officer Joseph Chineworth, and 1st Lt. Roscoe Brown would each be credited with a confirmed kill on three downed Me 262s. On their return flight they engaged several targets of opportunity, including two trains. The success of this mission earned the unit one of their three Distinguished Unit Citations, and the personal thanks of Gen. Lawrence of the 5th Bomb Wing (Bucholtz 108, 109).

Beyond their role as escorts for the 15th Airforce’s bombers, the 332nd would be engaged in a number of fighter bomber missions across the Meditteranean and Central Europe. These missions were conducted whenever time permitted between bombing raids and would see the squadron engage a number of targets. These would include airfields and various transportation targets varying from trains to river barges. A raid on August 30, 1944 would mark the unit’s most successful day when the 332nd attacked poorly camouflaged aircraft at Grosswardein airfield, Romania. In the ensuing strafing attack, they would be credited with the destruction of 83 aircraft with a further 31 damaged, ranging from 30 Ju 88’s, to a pair of super heavy Me 323 transport aircraft (Bucholtz 66). They would mount similar attacks against Axis airfields from Romania to Hungary.


Pilot’s of the 332nd, Lt. Clarence ‘Lucky’ Lester on the right, leads the group with 3 credited victories, all claimed on the same day. [National Archives]
The 332nd would end their campaign at an airfield in Cattolica, Italy, and was credited for the destruction of 111 aircraft in the air, 150 on the ground, 57 locomotives, 600 rail cars, and had flown 15,533 sorties (Bucholtz 116). It was a common myth that the squadron had never lost a bomber to enemy fighters, this being a rumor circulated by the press near the end of the war. This was not the case, but even with the failure over Memmingen, their bomber losses to fighters were half of the average and they were a considerable morale booster for the bomber crews of the 15th Airforce.

Flight Characteristics and Pilot’s Remarks

 

[P-51B pilot training manual]
The P-51B would prove to be an excellent fighter, but one that could present some challenges to those unaware of its quirks. It shared most of its general flight and handling characteristics with its older Allison powered predecessors, though some alterations to the design would make themselves felt, and not always to the plane’s benefit or pilot’s wishes.

Overall, the Merlin Mustang’s would prove to be fast and highly maneuverable, but with more complex flight characteristics than the Allison powered models that came before. Under most flight conditions, the plane was positively stable and possessed controls that were light and responsive. This aspect had been improved from the previous models, as the P-51B would be equipped with improved internally sealed and balanced ailerons which kept control stick forces light. These were rated very well, though pilots would note they were still ‘mushy’ at low speeds. However, as the plane’s top speed increased, it was capable of pulling maneuvers that could prove hazardous to pilots. Above 4g turns where a pilot without a g-suit was partially blacked out, the stick reversal could be harsh, but the worst of its effects were eliminated by a 20lb bobweight that was incorporated into the control system later on (Dean 350, 349).

The plane’s stall characteristics were mixed, but mostly mild. A one g stall in a clean aircraft was characterized by a roll to the right which came on after rudder buffering and aileron snatching, and was easily recovered from. Pilots were generally positive about the stall warning and recovery characteristics. However, its accelerated stall behavior proved to be far less universally understood. Some pilots claimed an easy recovery after ample warning, and others claimed it came on suddenly and viciously. Its low drag wings would contribute partly to this, as with its lack of air flow disturbances, stalls could come on without much warning. In the event of a spin, recovery was achieved by throttling back and pulling up while directing the rudder in the opposite direction of the spin. A spin could be serious trouble as a typical recovery resulted in a loss of about 9,000 ft in altitude (Dean 351, 352; P-51B flight manual 80).

While the plane was certainly very capable in regards to its maneuverability, pilots would have to take great caution when performing maneuvers of any kind when the fuselage tank still contained fuel. When the 85 gallon tank still contained fuel, the plane’s center of gravity shifted considerably and induced severe longitudinal instability. Hard maneuvers with any considerable volume of fuel still in the tank would result in a stick reversal that would require the pilot to brace themselves against the movement of the stick. Failing to do so would result in a loss of control or a further tightening of the turn which could result in a high speed stall or even structural failure (Dean 347, 348). Both RAF and USAAF manuals would ban aerobatics with roughly forty or more gallons of fuel in the tank, and suggested caution once it had been reduced to 25 gallons (Pilot’s Training Manual 68, Pilots Notes 30). In service this issue was one that rarely affected the plane’s effectiveness in combat, as the long range tank was the first to be used on long patrols and escort missions and thus typically contained little or no fuel when contact with enemy aircraft was made.

On early and mid production P-51B’s, pilots would also have to be cautious of high speed snapping brought on by the aforementioned longitudinal instability while they were conducting rolls. Pilots caught unaware were often injured during this violent jolt, and rolls were restricted accordingly. The addition of a fin extension for the vertical stabilizer and reverse rudder boost tabs would largely solve this issue, and the restrictions were lifted on suitably modified aircraft (Dean 350).

Perhaps where the aircraft shined the brightest were its dive characteristics, which were achieved as a result of its low drag wings and fuselage. These granted it excellent acceleration and a higher critical mach number than most of its contemporaries. Due to the changes in air flow across an aircraft’s wings as a plane approaches the sound barrier, most aircraft would experience buffeting, and a loss of control along and total loss of lifting forces. This change in flight characteristics that results in this loss of control is known as compressibility, a phenomenon that occurs when an aircraft exceeds the speed of its critical mach number.

A visual explanation of compressibility from the P-51B’s pilot training manual, the disturbed airflow results in a loss of lifting forces on the wings and control surfaces. The P-51’s wings mitigated the worst of its effects until much higher speeds. [Pilot’s training manual]
Thanks to its laminar flow airfoil, the P-51 was almost unique in its ability to remain controllable at otherwise unheard of speeds. However, in a high speed dive the P-51 would eventually experience compressibility and a pilot needed to be aware of the changing characteristics of their aircraft. In the P-51 this would first be felt through a ‘nibbling’ at the controls, afterwards by the stick ‘walking’ back and forth, and lastly by the aircraft pitching up and down with motions that grew more violent as the aircraft picked up speed (Pilot’s Training Manual 74, 75). On earlier models that lacked the vertical stabilizer extension, there was also directional instability that occurred at high speed, which required rudder correction or the plane could be sent into a spin. However with the later modifications the plane was nothing less than astounding. In diving tests from 35,000ft, pilots were able to reach mach .83 while retaining control of the aircraft, and despite the violent shaking and buffeting of the aircraft, were able to recover from the dive. In more practical conditions, control characteristics would remain normal until the aircraft was between .72 and .74 mach, after which the plane would experience escalating tuck-under, or a tendency to pull downwards airspeed increased. The maximum permissible dive speed was set at 505 mph IAS below 9000 ft, and 300 mph IAS at 35,000 ft, TAS being 539 mph (Mach .81). The maximum permissible engine RPM in dives was 3300 (Dean 341, 342, 343). Overall, the P-51B proved to be phenomenal in a dive, with only the British Hawker Tempest gaining a slight lead in tests, it being another aircraft equipped with laminar flow airfoils (Ethell 62).

Its take-off procedure was fairly typical of contemporary US fighters and required a strong right rudder deflection during take off to counteract the powerful torque from its engine. Its best climb out speed was between 160 to 170 mph IAS, which was quickly achieved after its flaps and landing gear had been retracted (Dean 341). Landing was somewhat more challenging, as the 140 mph IAS glide slope offered poor forward visibility, and little was improved as the plane came in to land at about 90 mph. It was thus fairly common for combat pilots to make tail up, level landings in order to have a better view of the landing strip before touching down. Its widely spaced gear and wide tire tread otherwise made the landing fairly easy.

While the P-51B’s possessed some truly phenomenal flight characteristics, the same cannot be said for the canopy. In US Navy evaluations the ‘birdcage’ canopy was found to result in poor all-around vision, most notably fore and aft. It was also fairly restrictive and made turning to view behind the aircraft more difficult (Dean 353). The frame itself could also not be opened on take off or landing and thus proved to be of some annoyance to pilots. This would later be solved with the addition of the ‘Malcom Hood’ which provided excellent visibility and was far less confining. The rest of the cockpit was judged to be satisfactory and capable of accommodating pilots of varying stature.

The ‘birdcage’ was unpopular as it was quite restrictive in terms of visibility, and it could not be kept open on the landing approach or takeoff. [Pilot’s Training Manual]
Its armament however, was distinctly lacking and fairly unreliable. It’s armament of four .50 caliber AN/M2’s was considerably lighter than most US fighters of the time and were installed in such a way that the ammunition links were prone to deformation in high-g maneuvers. It was not uncommon for P-51B/C’s to return from their missions with several guns malfunctioning as a result of failures to feed or extract. As a gun platform, its qualities were judged as roughly the same as the P-40, and below those of the P-38 and P-47 (Dean 353).

Comparisons with American Fighter Aircraft: Early to Mid 1944

Entering service alongside the P-47 and P-38, the new P-51’s would compare very well. When it came to the P-47D, equipped with R-2800-63’s, these aircraft were in some ways complementary, and excelled in areas the other did not. Thanks to its powerful turbosupercharger, the P-47 would retain the power needed to outperform the P-51 above 25,000ft, but was significantly slower at lower altitudes. The P-47 was also less vulnerable to ground fire and thus better suited for ground attack missions. The P-51B however, outstripped the P-47D in rate of climb, linear speed, acceleration at altitudes below roughly 30,000ft, and dive performance (Ethell 70; Marshall & Ford 526). Ergonomically speaking, the P-51B was the superior aircraft, as the turbosupercharger controls of the P-47D added to the workload of the pilot.

The P-47’s Turbosupercharged R-2800 engine provided unparalleled performance above 30k feet, and it’s durability made it ideal for fighter bomber missions. It was fairly lacking in its rate of climb and acceleration at low to medium altitudes. [National Archive]
When it came to escorting bombers, the P-47D and P-51B were the most effective tools at the USAAF’s disposal. Both aircraft performed superbly at and above the altitudes the bombers typically flew at, though the P-51B would prove the more vital as it could travel significantly further. By late spring 1944, external fuel tanks had been introduced that extended the P-47’s escort radius across most of Germany, however, by this time the P-51B was capable of accompanying bombers beyond Poland (Marshal & Ford 516). While the shorter range of this aircraft was often used to excuse the high bomber losses during earlier campaigns, the fact is that had they been supplied with the proper external fuel tanks, they would have been capable of deep incursions into German airspace months before the P-51 entered service.

The P-38 experienced serious reliability and performance issues due to the extremely low temperatures encountered at high altitude over Northern Europe. Its poor high altitude dive performance was also widely known, and exploited by Luftwaffe pilots. [National Archives]
The older P-38J Lightning would not stack up quite as favorably against the new Mustang. While the P-38J possessed a better climb rate and acceleration, it was out-stripped in linear speed by the P-51B at all altitudes, and possessed a very low critical mach number which meant that virtually any opponent at high altitude could escape by diving away. To make matters worse, a number of technical and operational issues spelled trouble for these aircraft in the colder Northern European climate. These issues, compounded by the extremely poor cockpit and canopy of the P-38, saw Lightning squadrons fall behind Thunderbolt and Mustang squadrons in victory credits (Marshall & Ford 439, 516; Ethell 70).

While the P-38J would receive external fuel tanks that would allow it to travel to Berlin and back, it was held back by a number of factors that severely reduced its combat effectiveness. In the European Theater of Operations, the P-51B would present a clear and general improvement over the P-38s, which saw more success in other theaters with conditions that they were better suited to, namely the Mediterranean and Pacific.

German Fighter Comparison: Early to Mid 1944

Entering service near the end of 1943, the P-51B compared very well to the German Fw 190As and Bf 109Gs in service at that time. The typical Bf 109 encountered through the first half of 1944 was the Bf 109G-6 series, which possessed better firepower than those that preceded it, but was heavier, and initially slower for it. These planes were equipped with either the Daimler-Benz DB 605A, or the high altitude, DB 605AS engines, both of which were later equipped with MW-50 boost systems. In all cases the P-51B possessed the superior linear speed, but in the case of MW-50 equipped aircraft, the Mustang had a slightly lower climb rate at low to medium altitude (Marshall & Ford 526, 523; P-51 flight tests). Without the boost system, which came into widespread use in the summer of 1944, the Bf 109G-6 was considerably slower and had a clear disadvantage in top speed and climb rate at all altitudes. The disparity with the high altitude model was much narrower, though the P-51 still held an edge.

The Bf 109G-6 was the most common Luftwaffe fighter encountered by the P-51. Later versions boasted considerably higher engine power thanks to the MW50 boost system; they did not compare well to many western allied fighters prior to this. Here one prepares for a fighter bomber sortie. [Asisbiz]
When it came to maneuverability, both aircraft had their own advantages, with the Bf 109 having better low speed handling and the P-51 having the advantage at high speed. The dive performance of the P-51B was far superior even at lower altitudes as the Bf 109 experienced stiffening of the elevator at high speed.

Visibility the Bf 109 was more or less on the same level of the standard ‘birdcage’ P-51B, and this would largely remain the case, as both planes would be re-equipped with improved canopies that offered better visibility. However, the cockpit of the P-51 was considerably more spacious and was further improved by the Malcolm hood. The Bf 109’s greatest strength was that it was equipped with an automatic RPM governor and mixture control that took a great deal of work off the pilot.

In terms of armament, both aircraft were comparable, with an unmodified Bf 109G-6 possessing a pair of 13mm machine guns and either a 20 or 30mm cannon, which fired through the propeller hub. Of the two, the 30mm was far less common.

Overall, the Bf 109G-6 was a somewhat dated fighter, one that had its advantages, but was  generally outclassed by the new Mustang. However, upgrades like water-methanol injection, an improved vertical stabilizer, and a new canopy helped keep the aircraft competitive and staved off obsolescence. The much refined ‘Kurfurst’ series would match P-51 performance in a number of areas, but its introduction was well after the Luftwaffe had lost control of German airspace.

The P-51B would face several models of the Fw 190A, with the most up to date being the A-8. The P-51B would have considerable linear speed, climb, and high altitude dive advantages over the earlier models. The Fw 190A-8 would have the benefit of a significant boost in power to its BMW 801D-2 engine, first by means of a fuel injection system, and in the summer of 1944, they were judged robust enough to be run at higher manifold pressures and had their supercharger boost regulators overridden. These modifications allowed the engine to produce significantly more power and increased the aircraft’s top speed at all altitudes (Douglass 344). In terms of top speed, this put these two aircraft on closer footing at low altitude, and ahead of the other two American fighters. It was, however, nowhere close to offsetting the general disparities at higher altitudes. The excellent defensive characteristics of the aircraft helped to offset some of its disadvantages against the P-51, as the Fw 190A held the best roll rate in the theater, solid dive characteristics, and good rearward visibility.

The Fw 190A’s were completely outclassed at altitude by the P-51B, owing to their relatively low full throttle height. They would however, be on somewhat closer footing at lower altitudes and could hold their own against the other two American fighters. [Asisbiz]
In terms of armament it was no contest, as the earlier A-6’s and A-7’s possessed a pair of either 7.92mm or 13mm machineguns respectively, and a pair of 20mm cannons. This was increased to two pairs on the Fw 190A-8. In regards to ergonomics the Fw 190A was excellent, with good visibility, clean instrumentation, and an advanced engine control system which handled RPM, manifold pressure, and mixture through the use of a single, integrated electro-mechanical computer. Its controls too were tight and responsive, if a little heavy at speed, thanks to its push rod control system. However, as was also the case with the Bf 109, its cockpit was comparatively cramped compared to the P-51.

Subsequent models of both these aircraft, the most numerous being the Bf 109G-14 and the Fw 190D-9, would largely eliminate the performance disparity at low altitude. However, at medium to high altitudes, the P-51 would still enjoy a considerable edge in top speed, dive performance, and high speed maneuverability. Only later Bf 109G’s with enlarged superchargers and better high altitude performance were close to closing the gap, with the K-4 series finally achieving high altitude parity near the very end of the war.


The Bf 109G-14 and the Fw 190D-9 would enter service in the Autumn and Winter of 1944, though they would not entirely replace their predecessors by the end of the war. [Largescaleplanes, Asisbiz]
The Me 262 presented a much greater threat in the air for obvious reasons. The jet fighter possessed a top speed roughly 100 miles per hour faster than the P-51 and was the only Luftwaffe fighter capable of following it into a dive. It was, however, considerably lacking in acceleration, which presented itself most dangerously on take off and on the landing approach. While the high top speed of the jets meant that they could disengage safely from most confrontations, they were helpless if caught near taking off or landing. Thus the general strategy for defeating these aircraft was to catch them as they were returning to their bases, where Allied fighters would await them. This is not to say this was easy, as their airfields were well defended by some of the best flak units available to the Luftwaffe and they would eventually have their own dedicated fighter cover (Ethell 97, 98). Higher up the jet could prove a deadly opponent as when flown well, it was extremely difficult to catch and an experienced pilot had control over most engagements.

The Me 262 was a world first, and had many USAAF planners concerned. On paper it had the ability to wreak untold havoc on allied bomber formations, but its technical limitations and the general poor state of the Luftwaffe late in the war prevented it from operating in numbers large enough to make a major impact. [Asisbiz]
In any case, encounters with the new jet fighters were fairly uncommon as they were constrained by operational restrictions owing to the temperamental nature of the new turbojet engines and the lack of a dedicated trainer for the aircraft until late 1944. They would not be seen flying against the Allies in appreciable numbers until the late autumn of that year.

Building the P-51B & C

The P-51B’s and C’s were built at plants in Inglewood, California, and Dallas, Texas, respectively. The distinction exists due to the differences in manufacturing between these two facilities, but these are functionally the same aircraft. With the exception of the earliest model, the P-51B-1, which had a different aileron design, their components were interchangeable. The main production models were equipped with the Packard V-1650-7 engine. Deliveries of these models began in February of 1944 (Marshall & Ford 253)

Production of this aircraft was complicated greatly by the breakneck pace of its procurement, which saw massive orders placed before its prototype had completed testing. As such, the aircraft that left the factories differed considerably even when they were built mere weeks apart. While all WWII fighters underwent constant modification, the level and rate of changes made to the P-51B and C were extensive and rapid. In addition to minimal changes, like changing the pilot’s seat from a wooden one to a magnesium one, in a matter of weeks the P-51B would receive an additional fuselage fuel tank, an extension to its vertical stabilizer and a rudder anti-balance tab, and an elevator control system which made use of a 20lb bob weight (Dean 329). These features would constitute a considerable challenge to work into the design without compromising the pace of production for an aircraft that USAAF planners wanted in as great quantity in the shortest possible time.

The Inglewood P-51 production line. [North American Aviation]
This challenge would highlight both the greatest strengths and weaknesses in US aircraft manufacturing. Most aircraft factories in the US operated by building large batches where the design would be frozen to allow faster construction. Modifying the design meant changes to the production line, which meant slowing down or stopping. US factories operated at batch sizes of up to 1,500, compared to the British Supermarine Spitfire’s production lines which operated at or below 500. The compromise was the modification center, to which “finished” aircraft would be delivered to be fitted out to new modifications. In practice, this system was extremely inefficient and saw quality control drop significantly. It also proved to be a highly inefficient use of labor, and could represent between 25 to 50% of the total labor required to complete an aircraft. Quality control also dropped considerably as the modification center was primed to try and deliver aircraft as quickly as possible (Zeitlin 55, 59). Lastly, the centers saw a great deal of wastage of material, accumulating a much larger proportion of metal scrap from rushed fittings, and ruined parts than the production lines (O’Leary 142). The USAAF would have its Mustangs, but only at a considerable cost and of initial questionable quality.

In the end they were successful in that they delivered the P-51B in great quantities despite the rushed pace of procurement, development, and production. However, it certainly contributed to the severe teething issues experienced by the aircraft that would see it briefly grounded in March of 1944 and would trouble it for weeks later.

In all, 1,988 P-51Bs were built with the first leaving the production lines, at a very low initial rate, in the summer of 1943 with the first deliveries taking place in August, with a further 1,750 P-51C’s being built. Production of both types declined as the P-51D production began in January of 1944, with the last P-51B’s leaving Inglewood in March and P-51C production continuing for several more weeks (Dean 321).

Construction

Wings

The wing group of the P-51 was composed of each wing, bolted together at the centerline. Each wing was of a cantilever stressed skin construction and consisted of a main panel, the wingtip, the flap, and the aileron. The main panel was built up around a main forward spar and a rear spar, to which twenty one pressed ribs were attached. These spars were spliced together roughly around half their length. A self-sealing 90 gallon fuel tank was fitted at the inboard section and a bay for its .50 caliber machine guns and ammunition was found near the center. The ailerons were of a fairly heavy construction, being all metal and supported by two spars and twelve flanged ribs. They were aerodynamically balanced by a diaphragm attached to the forward edge of the aileron and sealed to the rear spar by a fabric strip. These were controlled by means of a cable, as were all of the control surfaces of this aircraft. These were equipped with trim tabs and were adjustable in flight. The flaps were all metal plain flaps that were hinged on three sealed ball bearings and were hydraulically actuated.

[Legends in their time]
The landing gear was hydraulically actuated with a fully retractable tail wheel. The main landing gear were fixed to the wings by a cast magnesium supports and were equipped with multiple disc brakes connected to the hydraulic cylinder by metal tubing. The wheels were 27 inches in diameter and possessed a fairly wide tread, which helped to give the P-51 excellent ground handling.

The wings of the P-51 were designed to achieve laminar flow and used a NAA/NACA 45-100 series airfoil. It would fall short of true laminar flow as even extremely minor surface imperfections resulted in airflow disruptions that made laminar flow impossible. However, these were among the most aerodynamically advanced wings used by any fighter during the Second World War, providing extremely low drag and excellent high altitude dive performance.

Fuselage

[Legends in their time]
The fuselage was composed of two main sections, both of which had a semi-monocoque construction. The main section was formed by four extruded longerons, around which the intermediate frames and stringers were connected. The upper longerons were extruded H-sections which extended from the sheet metal firewall and tapered into a T-section. The lower longerons, consisting of an H-section and U-channel, extended the full length of the main fuselage. This entire unit was made up of eight assemblies which were riveted and bolted together, these being the firewall, turnover, truss, upper deck, left and right side panels, radio shelf, web assembly, and the radiator air scoop.

The main fuselage section also contained the cockpit, the windshield being composed of a center pane of bullet resistant five pane laminated glass, with two Plexiglas windows to either side. The canopy was either a metal framed Plexiglas ‘bird cage’, or a Malcom Hood. The birdcage had panels that opened outward on the top and port side. The hood slid back across the rear of the canopy. Behind the pilot were lucite windows which enclosed the radio space. A relief tube was installed and stored beneath the seat, and proved quite useful considering the long flights that this aircraft commonly made.

Early P-51B instrumentation. [Legends in their own Time]
The rear section was comparatively simple, composed of two longerons, a shelf, five formers, and three solid bulkheads. The fuselage, as with the rest of the aircraft, was skinned in Alclad. This section was reinforced after structural failures during high speed rolls in early models.

Tail Section

The tail section was affixed to the rear fuselage and consisted of the horizontal stabilizer, elevators, fin, vertical stabilizer, and the rudder. The horizontal stabilizer was a one piece assembly supported by two spars, fixed to the fuselage by four bolts, and through which the vertical stabilizer was attached. The elevators consisted of a front spar with eighteen flanged ribs, and was initially fabric skinned with Alclad leading edges before it was later entirely metal skinned. These were fastened with five sealed ball bearing hinges and each had an adjustable trim tab.

The vertical stabilizer was supported by two spars along with four ribs and a detachable tip. Extensions to the vertical stabilizer by means of a fin were added to P-51B/C’s to correct for longitudinal stability issues with a full fuselage fuel tank, and to correct certain undesirable characteristics when the aircraft was put through a roll. The rudder was fitted at the rear of the stabilizer and was supported by a single spar to which twenty flanged ribs were attached. Much of the rudder was skinned with mercerized cotton, save for the reverse edge. The rudder was fitted with a trim tab and aerodynamically balanced by means of a 16.6 lb lead weight at the tip.

Engine Section

The engine section consisted of the engine mounting and external cowl components and was bolted to the firewall. The cowl consisted of a frame made of Alclad beams to which the cowl panels fastened. This frame acts as a cradle for the engine which is mounted by a bracket through anti-vibration units. The entire section is designed to facilitate easy access to the engine through panels, and the engine mount allows for the rapid removal of the Packard engine.

[Legends in their time]

Engine

The early models of the P-51B used a Packard V-1650-3, with this engine being replaced on the production line in February of 1944 with the Packard V-1650-7. These are largely the same engine, though their superchargers were geared for optimal performance at different altitudes and thus have different maximum outputs. The 1650-3 was designed specifically for high altitude use and gave the P-51B/C a full throttle height of 29,000 feet, the 1650-7 was geared to achieve a higher engine output at a FTH of 21,400 feet (Marshall & Ford 253).

These engines had a bore of 5.40 inches, a stroke of 6 inches, a displacement of 1,649 cubic inches, a compression ratio of 6.0:1, a width of 30 inches, a height of 41.6 inches, length 87.1 inches, a frontal area of 5.9 sq. ft, and a weight of 1690 lbs. They differed in that the -3 supercharger ratios of 6.391:1 and 8.095:1, and those of the -7 were 5.80:1 and 7.35:1 (Wilkinson 125, 127). They were both fitted with a four blade Hamilton-Standard 24D50-65 or -87 hydropneumatic propeller with aluminum blades of a diameter of 11 feet and 2 inches. These blades were either 6547-6, 6547A-6, or 6523A-24 types. The engine exhaust stacks were of a stainless steel construction which had a removable exhaust shroud to keep heat from the spark plugs and to reduce drag.

Packard V-1650-7 [Pilot’s training manual, Smithsonian]
Both engines used a two stage, two speed supercharger and was equipped with an aftercooler. The supercharger was automatically controlled and governed by the air pressure at the carburetor intake, which was found just below the prop spinner. The controls for the engine were conventional, requiring manual throttle and rpm adjustments.

Radiator and Cooling Systems

The engine was cooled by two separate systems, one dedicated to the engine, and the other cooled the supercharged fuel-air mixture. Both of these systems were connected through the main radiator matrix within the air scoop below the main fuselage, with the coolant flow maintained by an engine driven pump. A smaller radiator for the oil cooler was placed below and ahead of the radiator matrix for the engine and aftercooler. The radiator setup was designed to make use of the Meredith effect, which in practical terms meant that the heated air flow out of the radiator produced thrust which counteracted a large percentage of the drag incurred by the scoop. The outlet for the radiator was automatically controlled. This design was able to reduce net drag upwards of 90% and was one of the most important features which allowed the aircraft to achieve such a high top speed (Marshall & Ford 510).

[Legends in their time]
The hoses for the radiator which extended through roughly two thirds of the aircraft, and the unarmored radiator, which sat at the bottom center of the aircraft, constituted the most vulnerable part of the aircraft’s design. These made the aircraft fairly vulnerable to ground fire, as the high cooling requirements of the Packard Merlin engine meant that a failure of the cooling system wouldn’t take long to put the aircraft out of action.

Fuel System

The initial models of the P-51B possessed only two 92 gallon wing fuel tanks with an 85 gallon fuselage fuel tank being included later through modification kits and was eventually incorporated into the production line. The Mustang was also capable of carrying two external fuel tanks by means of wing mounts. Fuel was drawn only from individual fuel tanks, requiring the pilot to manage up to five individual sources of fuel throughout longer flights (Pilot’s Training Manual 26).

[Pilot’s Training Manual]
The inclusion of the 85 gallon fuselage tank would introduce new challenges, as the shift in weight caused by a full tank introduced severe longitudinal instability. For this reason this tank was the first to be consumed. The combined tankage was 269 gallons.

Armament and Armor

P-51B’s were equipped with four .50 caliber AN/M2 machine guns. Each inboard gun was supplied with up to 250 rounds, with the outboard weapons having 350 each. These guns were mounted at roughly 45 degree angles within the wing, which caused severe cycling issues when the guns were fired while the aircraft was pulling hard maneuvers. These issues were lessened with the addition of electric boost motors for the ammunition feed, but were not completely solved until the subsequent P-51D model. The guns were electrically heated to prevent them from locking up at high altitudes. These aircraft were typically equipped with the N-3B reflector gunsight, with later aircraft receiving K-14 gyroscopic gunsights.

[National Archives]
Wing pylons allowed the aircraft to carry a payload of up to 500 pounds at either side, being either external fuel tanks or bombs. These aircraft could be made to carry rockets by means of field modification kits. Armor plates were placed ahead of the radiator header tank, at the engine fire wall, and behind the pilot.

(Dean 355-376)

Conclusion

It would take a considerable effort to develop the P-51B from its Allison engined predecessors, and even greater hurdles would have to be overcome to produce them in the quantities needed. In the end, both were achieved and the P-51B would enter large-scale operation in the Spring of 1944. In spite of its harsh teething issues, it would become among the most decisive weapons of the Second World War. With its incredible range and medium and high altitude performance, the aircraft would prove instrumental in establishing air superiority over Western Europe prior to Operation Overlord, and contesting the skies over Germany itself.

P-51B production was switched over to the D model at Inglewood in March of 1944, but the aircraft would remain in service in large numbers through the end of the war. [National Archives]
Its design, while not revolutionary, was thoroughly advanced and represented a considerable leap in aerodynamics and airframe design. The P-51B would however, be only a starting point for the Packard Merlin Mustangs, as further refinements would result in the iconic, and much more widely produced P-51D.

Specifications

P-51B/C ( with Fuselage tank) Specification
Engine  Packard Merlin V-1650-3, V-1650-7
Engine Output [V-1650-7] 1630 hp [1720 hp]
Maximum Escort Fighter Weight 11,150 lbs (2x108gal external)
Gross Weight 9,681 lbs
Empty weight 6,988 lbs
Maximum Range [External Fuel] 1350 miles [2150 miles]
Combat radius [External Fuel] 375 miles [750 miles]
Maximum speed (V-1650-7) 444 mph (75″ Hg) at 20600ft
Armament  4x .50 cal M2 machine guns, 1200 rounds of ammunition
Crew Pilot
Length 32′ 2
Height (tail down) 12’8
Wingspan 37.03′
Wing Area 235.75 sq.ft

 

P-51B/C ( with Fuselage tank) Specification
Engine  Packard Merlin V-1650-3, V-1650-7
Engine Output [V-1650-7] 1630 hp [1720 hp]
Maximum Escort Fighter Weight 5058 kg (2×409 liters external)
Gross Weight 4391 kg
Empty weight 3169 kg 
Maximum Range [External Fuel] 2172 km [3460 km]
Combat radius [External Fuel] 603 km [1207 km]
Maximum speed (V-1650-7) 714 km/h (1905mm Hg) at 6279 m
Armament  4x 12.7mm M2 machine guns, 1200 rounds of ammunition
Crew Pilot
Length 9.80 m
Height (tail down) 3.86 m
Wingspan 11.29 m
Wing Area 21.9 sq.m

(Dean, Performance Tests on P-38J, P-47D and P-51B Airplanes Tested with 44-1 Fuel., Marshall & Ford)

Maximum Level Speed Speed at 67″ Hg, 3000 RPM 75″ Hg, 3000 RPM No wing racks, 75″ Hg, 3000 RPM
Sea level 364 mph 380 mph 388 mph
Critical altitude low blower 408 mph at 10400 ft 411 mph at 2300 ft 422 mph at 7400ft
Critical altitude high blower 426 mph at 23900 ft 431 mph at 20600ft 444 mph at 20600ft
Aircraft Specification Gross weight 9680lbs, P-51B-15  (V-1650-7)

*A note on fuels: The 75″ of manifold pressure figure represents the high end of performance using 150 octane fuels, these were typically only available to P-51 squadrons based in England.

Climb rate 67″, 3000 RPM 75″ Hg, 3000 RPM
Maximum at low blower 3,920 ft/min at 5600 ft 4,380 ft/min 2,300 ft
Maximum at high blower 3,170 ft/min at 19,200 ft 3,700 ft/min at 15,600 ft
Aircraft Specification Gross weight 9680lbs, P-51B-15

 

Maximum Level Speed Speed at 1701 mm Hg, 3000 RPM 1905mm Hg, 3000 RPM No wing racks, 1905mm Hg, 3000 RPM
Sea level 586 km/h 611 km/h 624 km/h
Critical altitude low blower 656 km/h at 3169 m 661 km/h at 701 m 679 km/h at 2255 m
Critical altitude high blower 685 km/h at 7284 m 693 km/h at 6278 m 714 km/h at 6278 m
Aircraft Specification Gross weight 4390 kg, P-51B-15 (V-1650-7)

 

Climb rate 1701 mm Hg, 3000 RPM 1905 Hg, 3000 RPM
Maximum at low blower 1194  meter/minute at 1707 m 1335 meter/minute 701 m
Maximum at high blower 966 meter/minute at 5852 m 1128 meter/minute at 4755 m
Aircraft Specification Gross weight 4390 kg, P-51B-15

(Performance Tests on P-38J, P-47D and P-51B Airplanes Tested with 44-1 Fuel.)

P-51 Variants through P-51D

North American USAAF RAF Engine Armament No. Built Additional Notes. First delivery
NA-73X Allison 1 Prototype. October 1940
NA-73, -83 XP-51 Mustang Mk I Allison 2x .50 cal MG, 4x .30 cal MG 622 RAF, export. August 1941
NA-91 P-51 Mustang Mk Ia Allison 4x 20mm cannons 150 ‘Plain P-51’. July 1942
NA-97 A-36A Allison 6x .50 cal MG, bombs 500 Dive Bomber. October 1942
NA-99 P-51A Mustang Mk II Allison 4x .50 cal MG 310 March 1943
NA-101 XP-51B Packard 4x .50 cal MG 2 (converted) P-51B prototype
NA-102, -104 P-51B Mustang Mk III Packard 4x .50 cal MG 1988 Inglewood production. Summer 1943
NA-101, -103 P-51C Mustang Mk IIIB Packard 4x .50 cal MG 1750 Dallas production. August 1943
NA-106 (through -124) P-51D Mustang Mk IV Packard 6x .50 Cal MG +8000 Bubble canopy. January 1944

(Dean 321)

P-51B & C Variants

P-51B & C Variants Notes Serial No.’s
P-51B-1-NA Earliest production model, steel aileron diaphragms, two point aileron attachment.  43-12093 to 12492.
P-51B-5-NA Three attachment points per aileron, non-magnetic diaphragm.  43-6313 to 6352, 43-6353 to 6752, 43-6753 to 7112.
P-51B-7-NA B-1s and 5s which received a new fuselage fuel tank carried this designation. Aircraft often carried prior designation in practice. Converted aircraft.
P-51B-10-NA Production model with fuselage tank.  43-7113 to 7202, 42-106429 to 106538, 42-106541 to 106738.
P-51B-15-NA Engine changed to Packard V-1650-7 (previous models were converted to this engine via supercharger kits).  42-106739 to 106908, 42-106909 to 106978, 43-24752 to 106738.
P-51C-1-NT Same as P-51B-5-NA.  42-102979 to 103328
P-51C-2-NT C-1s which received a new fuselage fuel tank carried this designation. Aircraft often used prior designation in practice. Converted aircraft.
P-51C-5-NT Same as P-51B-15-NA. 42-103329 to 103378, 42-103379 to 103778.
P-51-C-10-NT Production model with stabilizing fin extension. 42-10818 to 103978, 43-24902 to 25251, 44-10753 to 10782, 44-10818 to 10852, 44-10859 to 11036, 44-11123 to 11152.
P-51C-11-NT Production model. 44-10783 to 10817, 44-10853 to 10858,44-11037 to 11122.
F-6C Photoreconnaissance. Converted Aircraft.
TP-51C Dual control trainer. Converted Aircraft.

(Marshall & Ford, O’Leary)

Video

Gallery

Illustrations by Ed Jackson

XP-51B, 312093. The XP-51B’s were a pair of earlier Mustangs converted to use the Packard V-1650-3. Their cooling systems would prove the most troublesome, though the general teething issues these aircraft experienced were harsh and varied.
P-51B-7-NA 43-6913 ‘Shangri-La’. Debden, UK 1944. Debden ,UK 1944. This aircraft was flown by Capt. Don Gentile of the 4th Fighter Group, one of the unit’s leading aces.
P-51B. 325th Fighter Group. Poltava, USSR 1944. The 325th was among the units that participated in Operation Frantic, where they supported a series of USAAF raids launched from within the Soviet Union during the summer and fall of 1944.
P-51B-5-NA, 43-12214 ‘Rebel Queen’. Debden, UK 1944. This aircraft was flown by Col. Don Blakeslee, Commanding Officer of the 4th Fighter Group. This aircraft is an early production P-51B which had been equipped with a Malcolm Hood bubble canopy, this modification greatly improved visibility.
P-51C-10-NT ‘By Request’. Ramitelli, Italy 1944. This aircraft was flown by Col. Benjamin Davis, Commanding Officer of the 332nd Fighter Group. This is a late model which has been fitted with a fin fillet, extending from the vertical stabilizer. This addition greatly improved the aircraft’s stability in rolls and high speed dives.

B-17’s accompanied by a P-51B over England, March 1945.[National Archives]
A collection of P-51’s accompany a flight of B-24s of the 8th Air Force, near England. 1944. [National Archives]
The Malcom Hood bubble canopy would offer pilot’s great visibility compared to the ‘birdcage’. [National Archives]
The P-51A can be easily differentiated from its merlin powered counterpart by the tube shaped carburetor intake over the nose. [wikimedia]
Though most P-51B’s would be sent to Europe, some would serve in the China-Burma-India theater. Here a Mustang cruises alongside a C-47. [National Archives]
Ground crew pose alongside one of their planes. [National Archives]
A P-51B in the CBI theater is cleaned. This plane has had its exhaust fairing removed, a fairly common modification made in the field which some pilots believed cut down on drag. [National Archives]
A P-51B comes in to land, the wide tire tread and wheel base of these planes helped give these planes good landing and ground handling. [National Archives]
Ground crew pose with one of their planes, the tail fin extension as equipped to this plane helped alleviate some of the aircraft’s less desirable characteristics when it was rolled. [National Archives]
Among the challenges caused by segregation for the 332nd were personnel shortages. The only available training facility at Tuskegee struggled to turn out enough pilots and ground crew to support the segregated squadrons. Mechanics and armorers were among the most affected, especially when the fighter group rapidly transitioned from P-39’s, P-47’s, and P-40’s to P-51’s over the late spring and summer of 1944. [National Archive]
P-51B’s of the 325th Fighter group accompany bombers on their way to the Soviet Union during Operation Frantic. [National Archives]
The success of Operation Overlord saw the redeployment of many USAAF units to the continent. These P-51’s of the 9th AF were the first to be deployed to France. [National Archives]
The F-6C was a photo-reconnaissance variant that had a camera installed in the fuselage, the lens cover for which sits here just behind the radiator scoop. This model was credited with the last kill in the ETO, after downing a Fw 190 on May 8 1945 (Dean 339). [Wikimedia]

Credits

  • Written by Henry H.
  • Edited by  Ed Jackson & Henry H.
  • Illustrations by Ed Jackson

Sources

Primary:

  • Flight Tests On The North American P-51B-15 Airplane, AAF NO. 43-24777, 1944.
  • Preliminary Results of Performance Tests on a P-51B Airplane with 44-1 Fuel P-51B-5-NA, V-1650-7 Engine. 1944.
  • P-51B-15-NA 43-24777 (Packard Merlin V-1650-7) Performance Tests on P-38J, P-47D and P-51B Airplanes Tested with 44-1 Fuel. (GRADE 104/150). 15 May, 1944.
  • Matthews, H. F. Elimination Of Rumble From The Cooling Ducts Of A Single-Engine Pursuit Airplane. NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS. 1943.
  • Messerschmitt A.G. Augsburg. (1944). Leistungen Me 109 G-14/U4 mit Db 605 Am u. Asm. 1944.
  • Pilot Training Manual for the Mustang. United States Army Air Force, 1943.
  • Pilot’s Flight Operating Instructions P-51B-1 Airplane. Evansville, Indiana: United States Army Air Force, 1943.
  • Pilot’s Notes for Mustang III Packard Merlin V-1650-3 Engine. Air Council, 1944.
  • Wilkinson, Paul. Aircraft Engines of the World. 1944.
  • The United States Strategic Bombing Survey: Over-All Report (European War). U.S. Govt. Printing Office, 1945.

Secondary:

  • Bucholtz, Chris. 332Nd Fighter Group: Tuskegee Airmen. Oxford: Osprey Publishing, 2007.
  • Bucholtz, Chris. 4Th Fighter Group “Debden Eagles”. Oxford: Osprey Publishing, 2008.
  • O’Leary, Micheal. Building the P-51 Mustang the Story of Manufacturing North American’s Legendary WWII Fighter in Original Photos. Specialty Pr Pub & Wholesalers, 2011.
  • Dean, Francis H. America’s Hundred Thousand: the US Production Fighter Aircraft of World War II. Schiffer Publ., 1997.
  • Douglas, Calum E. Secret Horsepower Race: Second World War Fighter Aircraft Engine Development on the Western Front. TEMPEST, 2020.
  • Ethell, Jeffrey L. Mustang: A Documentary History of the P-51. London: Jane’s, 1981.
  • Haulman, Daniel L. Nine Myths about the Tuskegee Airmen. October 21, 2011.
  • Marshall, James William; Ford, Lowell. P-51B Mustang: The Bastard Stepchild that saved the Eighth air force. Bloomsbury Publishing Plc. 2020. (Electronic)
  • Moye, J. Todd. Freedom Flyers: The Tuskegee Airmen of World War II. New York, NY: Oxford University Press, 2012.
  • Overy, Richard James. The Bombing War: Europe 1939-1945. London: Penguin Books, 2014.

IAR H.S.300

Romania Flag Romania (1934)
Training and Reconnaissance Aircraft – None Built

Cutout view of the IAR-H.S.300. Note the turret with the machine gun, camera and tandem controls. [Dan Antoniu]
The establishment of I.A.R. (Industria Aeronautică Română) at Brașov in 1925 was a huge step forward for Romanian industry, and more importantly, the A.R.R. (Aeronautica Regală Română) Romania’s Royal Air Force. However, with the turn of the decade and rapid development of military aircraft around the world, Romanian aircraft factories, which also included S.E.T. (Societatea pentru Exploatări Tehnice) and the new I.C.A.R. (Întreprinderea de Construcții Aeronautice Românești), were lagging behind in terms of equipment and production facilities. This led to a variety of issues which pushed IAR into bankruptcy. The IAR H.S.300 was IAR’s last attempt at creating an aircraft for the ARR before drastic changes were made, both in terms of the plant’s management and the air force’s requirements and needs.

Development

With the deteriorating stability in 1930s Europe, Romania’s M.A.N. (Ministerul Apărării Naționale, Eng: Ministry of Defense) decided that all of its future aircraft had to be of all-metal construction. This caused a lot of issues with the national aircraft manufacturers, which simply did not have the equipment and facilities to produce all-metal aircraft. Similar issues plagued all Romanian industries even during the Second World War.

Between 1930 and 1933, IAR developed several competent fighter aircraft designs, but none were accepted into service due to their construction, which was part metal, part wood. This would force IAR into bankruptcy. Only a small order of 20 IAR-14 fighters was placed in early 1933, under clandestine conditions, directly from the Romanian high command to the factory.

One of the 20 IAR-14 monoplane fighters produced by IAR for the ARR in 1933. It came as a very much needed show of support to the factory, which was hemorrhaging money. [All the World’s Aircraft]
Things changed, however, in 1934, when the leadership at IAR requested an investigation from the Romanian Senate. They accused the MAN of not respecting the previously signed contract, ordering 100 aircraft and 150 engines per year, and buying foreign aircraft instead. In a meeting, a MAN representative responded to the allegations with the following:

“The majority of countries on the world stage have, starting from 1930, begun to equip their own air forces with planes built entirely out of metal, offering much better performance. This also being the policy of the Ministry of Equipment of the Romanian Air Force, taking into consideration the international situation, which is deteriorating swiftly, as long as the IAR factory will continue to only build aircraft from wood or mixed wood-metal, we are not interested, and will continue to rely on imports!”

During the same period, IAR developed a handful of new aircraft, one of them being a reconnaissance, observation, and training monoplane which was proposed directly to the S.S.A. (Subsecretariatul de Stat al Aerului). The blueprints and design specifications of the aircraft were discovered by Giorge Ciocoș at the Pitești archives.

IAR-22 trainer, which is what documents claim the H.S.300 was based on [Istoria Aviației Române]
IAR-23, which also has a vast amount of similarities to the H.S.300. [Airwar]
The plane was directly based on the IAR-22 trainer according to the factory documents, but a close analysis shows that it borrows details from several IAR aircraft, such as the empennage, which is borrowed from the IAR-23. Several other dimensions are the same as the IAR-23, such as the tailplane. It is entirely possible that the IAR-23, which was developed in March of 1934, served as a basis or inspiration for the IAR-H.S.300, as it was developed only 4 months later, in July 1934. Curiously, the documents continue to claim that the project was based on the IAR-22, stating that the wings are from the IAR-22, while a simple comparison of drawings or photos clearly shows that they are from the IAR-23. Additionally, the wings are identical to the IAR-21, which had undergone static testing in August of 1932.

Design & Construction

In the IAR documents, the aircraft is never officially given a name, instead titled as “IAR plane for training of reconnaissance and observation equipped with Hispano Suiza 300 hp engine.” Hence, it was given the unofficial moniker IAR-H.S. 300, referencing the engine. There are 7 documents detailing the layout and construction of the aircraft, with an additional 5 schemes and drawings showing the dimensions and design.

Structural side view of the IAR-H.S.300 [Dan Antoniu]
The IAR-H.S.300 was a rather small monoplane, with a wingspan of 12 meters, and a total length of 8.45 meters. Empty, the plane would weigh 989 kg, and 1,420 kg fully equipped with radio and other onboard equipment.

The wing would be made entirely out of spruce, consisting of the central frame, with a length of 3 meters, and the wings themselves, at 4.5 meters each. The wings would be built upon two wooden spars, and the wing shape made from plywood. The longerons were attached to the rest of the aircraft frame via duralumin 90 degree braces. The leading edge and central portion were wrapped with plywood, while the trailing edge and flaps were covered with cloth. The horizontal stabilizers were also of wooden construction and wrapped with cloth.

Top view of the IAR-H.S.300 with measurements. Note the shape of the wings. [Dan Antoniu]
In terms of the frame, it was made out of 4 spruce longerons, attached to each other via diagonal wooden supports. The attaching points were out of duralumin, and fastened with rivets. The fuselage that wrapped around the body was made out of sheet metal in the front and around the engine, plywood around the center and cloth on the tail. The elevator had a duralumin frame, but was covered with cloth, while the vertical stabilizer was made entirely out of duralumin construction and wrapped with cloth.

Frontal view of the IAR-H.S.300, showing its wooden propeller. [Dan Antoniu]
The landing gear was conventional, consisting of two wheels with brakes and shock absorbers. It was fixed and reinforced with a diagonal truss. Total weight of the landing gear would be 65 kg.

As for fuel reserves, the aircraft would’ve had two fuel tanks, one in each wing, with a capacity of 115 liters each (230 total) but there was the possibility to increase it up to 500 liters total. The oil tank had a capacity of 18 liters.

Clear side view of the IAR-H.S.300. [Dan Antoniu]
As mentioned previously, the engine was a Hispano Suiza 8Fb, a 18,5 L V-8. It had between 312 to 320 horsepower at normal power, and a maximum of 337. Typical revolutions per minute were 1,800 rpm and max was 2,100 rpm. Total weight was 275 kg. First variants were developed in 1914 and would be one of the most used engines by the Entente Powers during the First World War, which Romania was a part of, but later variants remained widely used throughout the 1920s and 30s. This powerplant would theoretically allow the IAR to reach a top speed of 238 km/h at 2,000 meters. Max ground speed was 245 km/h. Landing speed was to be 92 km/h. Range was 750 km with the 230 liter configuration. Time to altitude of 3000 meters was 8 min and 30 seconds.

The Hispano Suiza 8Fb V-8 engine. [Wiki]

Crew and Equipment

As a typical observation and training aircraft, there were two seats in the plane, both equipped with steering controls. The pilot is seated directly above the wings, in an open cockpit. He sat low in the plane’s body, with only his head protruding, protected by a small windshield.

The second aviator sat right behind the wings, higher up than the pilot for better visibility. He sat in a rotating turret that had a machine gun equipped, what type is unspecified. Below him were three drums, with 100 rounds each (300 total). A standard A.T.R. 4 radio was also available. The photo camera was positioned behind the turret, but could be operated from within the turret. Although the turret allowed for enough space to maneuver comfortably, the crewmans parachute was placed in a shelf behind him, for more efficient mobility.

Faith

Ultimately, the S.S.A. rejected the IAR-H.S.300. While the Air Force did need new observation and training aircraft, its method of construction and materials used were not accepted by the MAN and MAM (Ministerul Aerului și Marinei). Despite this, the plane seemed to be adequate for its role and time, with modern radio and photography devices, a turret and a respectable engine. Had IAR been able to produce a prototype and offer improvements, such as a fully enclosed cockpit, it would have been a competitive aircraft in its role. Unfortunately, IAR was bankrupt and unable to promote its designs.

IAR-27 light bomber and reconnaissance aircraft, built in the years prior to the war, more or less out of desperation. [Airwar]
The salvation of IAR came in 1936, when Poland became the only supplier to grant Romania production licenses. M.A.N. purchased licenses for the production of the Polish PZL-11 and PZL-24 aircraft, which had full metal fuselages, and were decent aircraft for their time. This required vast investments into the IAR factory, for the tooling and production facilities, and also the personnel and design bureau.

However in 1938, with war knocking at Europe’s door, the M.A.N. equipped the Romanian Air Force with whatever the factories could produce, such as the IAR-37, IAR-38, and IAR-39, which likely wouldn’t have been produced if the IAR-H.S.300 had been pushed into service and upgraded, as they were also reconnaissance and light bomber aircraft. These aircraft did not prove to be a significant upgrade, and were also built out of a combination of metal and wood, but circumstances forced M.A.N. to buy them regardless.

Conclusion

The IAR-H.S.300 was a small reconnaissance and training aircraft developed as a last ditch attempt by IAR for the Romanian Air Force. However due to its construction consisting of part metal, part wood combined with the Romanian Ministry of Defence’s reluctance to accept such planes, the project died quickly. In the end, the Romanian Air Force was forced to purchase mixed construction wood-metal planes from IAR, due to the mounting hostilities of late 30s Europe.

Acronyms and Translations

  • I.A.R. (Industria Aeronautică Română) Eng: Romanian Aeronautic Industry
  • A.R.R. (Aeronautica Regală Română) Eng: Royal Romanian air force
  • S.E.T. (Societatea pentru Exploatări Tehnice) Eng: Technical Exploitation Society
  • I.C.A.R. (Întreprinderea de Construcții Aeronautice Românești) Eng: Romanian Aeronautics Construction Company
  • M.A.N. (Ministerul Apărării Naționale, Eng: Ministry of Defence
  • S.S.A. (Subsecretariatul de Stat al Aerului) Eng: State Subsecretary of Air
  • MAM (Ministerul Aerului și Marinei) Eng: Ministry of Air and Navy

IAR H.S. 300 Specifications

Wingspans 12 m / 39 ft 4 in
Length 8.45 m / 27 ft 9 in
Wing Area 21.9 m² / 71.9 ft²
Engine Hispano Suiza 8Fb V-8, 312 hp
Empty Weight 989 kg / 2,180 lb
Maximum Takeoff Weight 1,429 kg / 3,150 lb
Fuel Capacity 230 liters / 60.75 gal
Maximum Speed 238 kph / 147 mph
Time to Altitude 3,000 meters / 9,840 feet – 8 min 30 sec

4,000 meters / 13,120 feet – 13 min 0 sec

5,000 meters / 16,400 feet – 19 min 10 sec

Range 750 km / 466 miles
Crew 1 Pilot & 1 Radio Operator/Photographer
Armament Single Machine Gun (Unspecified) 3x 100 Round Drum Magazines

Gallery

Artist Conception of IAR HS.300 – Illustration by Godzilla

Credits

  • Written by Pavel Alexe
  • Edited by Henry H., Ed Jackson, & Stan Lucian
  • Illustration by Godzilla
  • Special thanks to Dan Antoniu and Eng. L. C. Tascau

Sources

  • Dan Antoniu, Aviatia ilustrata, No.1 2018
  • Pitesti Archives