To protect their airspace as the Second World war ravaged Europe, Sweden wanted to acquire more modern fighters. Initially, they purchased American fighters, but the few they could order were insufficient and would be soon out of date. Luckily for Sweden, Italy was in short supply of vital metal ore, so it was that the Swedish Air Force managed to acquire 60 Re.2000 fighters. These were immediately put to service and proved to be the best fighters that Sweden had in its inventory during the war.
As the war in Europe broke out in 1939, Sweden tried to use its geopolitical and geographic position to remain neutral. Despite its neutral position, it still needed to acquire weapons and other pieces of military equipment to protect its border in case of any potential attack. Just as the war in Europe started, Sweden’s military officials purchased 120 P-35 Seversky fighters from the US to strengthen its air force. The first contingent of 60 aircraft reached Sweden in early 1940. The second group never reached Sweden, as the US Government canceled this agreement.
Despite ordering 120 P-35 Seversky fighters only half that number ever reached Sweden. Source: comandosupremo.com
The Swedish Armed Forces, not wanting to be left defenseless against an enemy air force, instead approached the Italians. Luckily for them, the Italians had developed and produced the Re.2000 which was essentially an improved copy of the US P-35. The Swedish government requested the purchase of 60 aircraft of this type. The official agreement was signed on the 28th of November 1940. As payment, Sweden agreed to give the Italians vital ore resources such as chrome and nickel.
Through Italy, Sweden managed to acquire 60 Re.2000 fighter aircraft in 1941. Source:www.destinationsjourney.com
Re.2000 Brief Development History
In 1938, the development of the Re.2000 by Reggiane began at the request of the Italian Aviation Ministry. The Italian Air Force at that time wanted to introduce more modern, low-wing fighters. By then, several different fighter designs were in various states of development. Reggiane formed a team of engineers with the aim of creating such a fighter, led by the Technical Director Antonio Alessio, and Engineer Roberto Longhi. Due to a lack of time to design an aircraft from the ground up, a solution was made to utilize some elements of the design of the US Seversky P-35. The main reason why the Re.2000 was influenced by this US design was Roberto Longhi. He had spent some time working in the aviation industry in America before returning to Italy in 1936. While the two planes look very similar, there were some differences, like the cockpit, and landing gear. Due to the lack of interest of the Italian Air Force Officials, fewer than 170 aircraft of this type would be produced. Most were exported, and only small quantities of this fighter were ever operated by the Italian Air Force.
The first Re.2000 reached Sweden in 1941. It was disassembled and then transported by rail through Germany and finally to Sweden. Once there, it was transported to the Swedish Air Force central workshop at Malment to be reassembled, after which the first trial and evaluation flights were carried out in September 1941. Once all 60 arrived, these were allocated to the F 10 Kung. Skanska Flyglottiljen (Eng. Fighter wing) unit. Their primary base of operation was the airfields at Bulltofta and Rinkaby. In Swedish Service, the Re.2000s were renamed to J20. The ‘J’ stands for Jacktplan, meaning a fighter. These received serial numbers from 2301 to 2360. The last two digits of these numbers were painted (in white color) on the aircraft tails and engine.
In general, the overall flight performance of the J20 was deemed sufficient. Its greatest downside was its poor mechanical reliability, and the difficulty in maintaining its engine. The Italians never tested the Re.2000’s performance in a cold climate, as it was intended for service in the Mediterranean. Because of this, the Swedish maintenance crews had to find out the hard way that the aircraft was simply not suited for the cold climate in the North. Trouble starting the engine in cold weather would prove a common, and frustrating exercise.
The J20 mainly saw service in the role of the interceptor. Their job was to intercept any aircraft that came near Sweden’s airspace. These were in the majority of cases, damaged Allied aircraft that were returning from bombing raids in Germany. On rare occasions, some German aircraft would lose their way and be intercepted by the J20. The interception operations were not intended to engage incoming aircraft but to simply escort them to the Bulltofta airfield, where the plane and its crew would be interred.
During the war, some 16 J20s were lost in various accidents but only one was shot down in combat. During a routine patrol on the 3rd of April 1945, a J20 piloted by Erik Nordlund spotted a German Do 24 aircraft that was flying near Nahobukten. As the J20 approached the German plane it was hit by 2 cm cannon rounds. While the pilot disengaged and tried to fly back, the engine exploded in midair, destroying the aircraft and killing the pilot. The J20s that survived the war remained in the inventory of the Sweden Air Force up to 1955 before being finally removed from service.
Besides their national marking, the Swedish added two large two-digit designations to the J20. These large numbers were painted in white color. Source: www.destinationsjourney.com
Surviving aircrafts
Most were either lost or scrapped, and today, only one J20 is preserved. It is currently exhibited at the Swedish Air Force Museum at Linkoping. This is the only known surviving Re.2000 in the world.
The Re.2000 was designed as a low-wing, mixed-construction, single-seat fighter plane. The fuselage consisted of a round frame covered with a metal sheet held in place using flush-riveting. The Re.2000 wings had a semi-elliptical design, with five spars covered with stressed skin. The central part of the wing held two integral fuel tanks. The tail section had a metal construction with the controls covered with fabric.
The landing gear system was unusual. When it retracted, it rotated 90° (a copy from the Curtiss model) before it entered the wheel bays. For better landing handling, the landing gear was provided with hydraulic shock absorbers and pneumatic brakes. The smaller rear wheel was also retractable and could be steered.
The Re.2000 engine was the Piaggio P.XI R.C.40 14-cylinder air-cooled radial engine, providing 985 hp, equipped with a three-blade variable pitch propeller made by Piaggio.
The cockpit canopy opened to the rear and the pilot had a good overall view of the surroundings. For pilot protection, a 8 mm (0.3 in) thick armor plate was placed behind the seat.
The Re.2000 possessed weak offensive capabilities, as it was armed with only two Breda-Safat 12.7 mm (0.5 in) heavy machine guns. The machine guns were installed in the forward front fuselage and fired through the propeller arc. For each machine gun, 300 ammunition rounds were provided. The Re.2000 also had two small bomb bays placed in each central wing section. Each bomb bay had a payload of twenty-two 2 kg (4.4 lb) anti-personnel or incendiary bombs.
Conclusion
The J20 was the best fighter in service within the Swedish Air Force. It was noted that during its service it possessed good overall flight characteristics. There were several issues with its maintenance, but this was mainly attributed to the cold Scandinavian Climate. In conclusion, while not the best fighter of the Second World War, for the country as Sweden it was more than enough to protect its airspace.
Re.2000 Specifications
Wingspans
11 m / 36 ft
Length
8 m / 26 ft 5 in
Height
3.15 m / 10 ft 4 in
Wing Area
20.4 m² / 220 ft²
Engine
One Piaggio P.XI RC.40 985 hp
Empty Weight
2,460 kg / 5,424 lbs
Maximum Takeoff Weight
3,240 kg / 7,140 lbs
Climb Rate to 6 km
6 minutes 10 seconds
Maximum Speed
515 km/h / 320 mph
Cruising speed
450 km/h / 280 mph
Range
840 km / 520 miles
Maximum Service Ceiling
11,500 m / 34,450 ft
Crew
1 pilot
Armament
Two 0.5 in (12.7 mm) heavy machine guns
44 kg bombs
Swedish J 20 (Re.2000) with 42 marking number
Credits:
Written by Marko P.
Edited by Henry H.
Illustration by Pavel
Source:
G. Punka (2001) Reggiane Fighters in Action, Squadron/signal publication
D. Nešić (2008) Naoružanje Drugog Svetsko Rata-Italija. Beograd.
D. Monday (2006) The Hamlyn Concise Guide To Axis Aircraft OF World War II, Bounty Books
M. D. Terlizzi. (2002). Reggiane Re 2000: Falco, Heja, J.20. IBN
G. Cattaneo () The Reggiane Re.2000, Profile Publication
Italy (1932)
Experimental Aircraft – One Prototype Built
In the history of aviation, there have been many projects that on paper promised outstanding flight capabilities, or offered other technical advantages. The time before the Second World War saw aviation advance at a breakneck pace, and is well known for such experiments. The so-called Stipa-Caproni was one such project, being an intriguing, and somewhat bizarre, experimental aircraft designed by Italian aeronautical engineer Luigi Stipa, and built by Caproni during the interwar period. It was characterized by its tubular fuselage, hence earning it the nickname Flying Barrel.
The unique design Stripa-Caproni experimental aircraft. Source: Wiki
History
In 1927 a young Italian aircraft engineer Luigi Stipa began working on an unusual tube-shaped aircraft. Like many other aviation enthusiasts, Stipa was very interested in how aircraft could achieve better performance through exploring unorthodox construction methods. Thanks to his studies in thermodynamics, he was aware of the so-called Venturi effect, named after Italian physicist Giovanni Battista Venturi. In essence, this effect describes the reduction of fluid pressure and increasing velocity when it’s moving through a cylinder of decreased diameter. In theory, using this principle, a special type of aircraft could be created that could achieve significantly higher speeds than the conventional models of the time. Stipa theorized that for this purpose, such an aircraft would have to have a tube-shaped fuselage with the engine being positioned near the front. After finding it theoretically possible, he moved forward to test if the Venturi effect could be implemented in his airplane concept. For this purpose, he began a series of different tests inside a wing tunnel, carried out at the Aerodynamic Laboratory in Rome, from 1928 to 1931. The main focus of this testing period was to find the adequate shape, and leading edges, of the tube-shaped fuselage. This also included finding the right position of the engine, its position inside that tube, and the ideal propeller rotation speed. Following a series of wind tunnel tests, Stipa concluded that it was possible to build a full-scale prototype by using a single tube-shaped fuselage.
Luigi Stipa in his younger years. Source: Wiki
At the end of his research, he concluded that such a project was viable and set the task of building a working prototype. To gain interest in his project, he wrote about his work in the Rivista Aeronautica journal in 1931, and even built a small working replica. The next logical step was to write to the Italian Minister of Aviation, in the hope of getting approval for the realization of his project. Luckily for Stipa, his work came to the attention of General Luigi Crocco, the Air Ministry’s director. Stipa’s work was well received and the project received a green light. To test the concept, a working prototype had to be constructed. It is important to note, that both Stipa and the Italian Air Ministry were aware that this project was merely to test his theories, and would not entail any further development of the prototype. In addition, both were aware that Stipa’s proposed principle was only practical on larger aircraft types.
For this purpose, the prototype was to be powered by a small 120-hp engine. The reason behind this decision lay in the fact that this aircraft was primarily built for evaluation and academic purposes. The Italian Air Ministry was not quite willing to invest huge monetary resources in it, beyond those necessary for the construction of the working prototype.
To help build the test aircraft, the Caproni aircraft manufacturer from Milan Taliedo was chosen. It was designated as Stipa-Caproni (sometimes referred to as Caproni-Stipa) referring to its designer and constructor. The prototype was built quickly and was ready for testing in October 1932.
It is perhaps a little surprising that such an unusual design would receive the necessary support for its realization. However, the exploration of new and unorthodox ideas in aviation was very popular in pre-war Europe. During the 1930s, Italy led the way in this aspect, perhaps even more than other countries, testing many unorthodox designs. What’s more, the Italian Fascist regime even encouraged different and unusual projects like this one, although many of them did not produce any meaningful results.
The Stipa-Caproni prototype was used for testing during 1932 and 1933. Source: en.topwar.ru
Technical specification
The Stipa-Caproni was a two-seater, mixed-construction aircraft, designed to have the simplest and thus cheapest fuselage. Its fuselage consisted of a tube which internally consisted of two large wooden round-shaped rings at the nose, followed by a series of similar but smaller rings. All of them were then connected with horizontal ribs which in turn were covered in fabric. The outer wooden rings served as the foundation, on which the wing and the cockpit would be connected. The fuselage design was, in effect, a large tube shaped airfoil.
A close-up view of the Stipa-Caproni internal fuselage construction. The two larger wooden rings serve as a base to which wings and the cockpit would be attached. Source: www.thevintagenews.com
The wings were mounted centrally on each side of the fuselage. These had a simple wooden construction, and were covered in fabric. They were also connected to the fuselage through metal bracing wires, which as a consequence increased the aircraft’s drag.
To the rear, a fairly large tail assembly was placed. During the design work of this aircraft, Stipa intentionally placed the rear control surfaces as close to the slipstream as possible. He hoped that this arrangement would greatly improve the aircraft’s handling and maneuverability.
On top of the fuselage, an elevated two-seat cockpit was placed. These were top-open with a small windshield placed in front of each position. There were also a pair of small doors that opened on the left side to give access to the seats.
The 120-hp de Havilland Gypsy III engine was placed inside this fuselage. It was centrally positioned and suspended using several steel bars that held it strongly in place. This was necessary to do so, as a weaker mounting could potentially endanger the aircraft during flight. The engine propeller was the almost the same diameter as the tube-shaped fuselage.
Given its overall design, and the position of the propellers inside the fuselage, the landing wheels were small and quite close to the ground. It consisted of three fixed road wheels. Two larger on the front and one smaller on the rear. Initially, wheel fairings were used but at some point, and for unclear reasons, these were removed.
A front view of the unusual engine installation. The engine itself was held in place by several metal bars. Source: WikiIt was provided with a small and fixed three-wheel landing gear. Source: en.topwar.ru
Testing and Final Fate
With this project approved, a prototype was constructed and air tested in October 1932 at the experimental field at Monte Celio near Rome. Despite its odd design, the prototype was able to take to the sky without any major problems. Furthermore, it made several successful flights around Taliedo and Guidnia. It was even presented to the Italian Air Force for future test flights. During this period the aircraft was jokingly nicknamed Flying Barrel or Aereo Botte (Eng. Wooden wine barrel aircraft) or Aereo Barile (Eng. Fuel-Barrel aircraft).
The weight of the aircraft during these flights was 800 kg (1,874 lb), while the calculated wing loading was 44,73 kg/m² (9,16 lb sq.ft.). The maximum speed achieved was 133 km/h (83 mph), and it needed 40 minutes to climb at a height of 3, 000 m. It needed an 800 m long airfield to be able to take to the sky.
The Stipa-Caproni during one of many test flights. Source: www.historynet.com
Despite Stipa’s hopes that the position and shape of the tail control surfaces would improve its mobility, several problems were noted by the test pilots. Firstly the elevator worked very well, which ironically proved to be a major problem. Even with a slight movement of the command control stick by the pilots, the aircraft could prove very sensitive to elevator inputs. On the other hand, the rudder controls were quite stiff, as a consequence the pilot had to use considerable force in order to use it effectively. Analyzing this problem showed that the rudder’s large surface area was to blame for its stiff control. But besides the two problems, the aircraft was reported to be easy to fly when being used in a gliding flight. These defects were of a more or less technical nature, which were not necessarily irremediable through further development of the overall design.
The design of the rear tail assembly proved somewhat problematic. Specifically, the elevator control was overly sensitive while the rudder was quite the opposite. Source: en.topwar.ru
The final results of evaluation flights showed that the Stipa-Caproni does not have any particularly great advantages compared to other more standard aircraft designs. In addition, Stipa-Caproni’s overall aircraft shape offered limited space within the fuselage for passengers or payload.
As Stipa predicted from the start, his principles would not offer any major advantage over a standard smaller-dimension aircraft. The real application of the Stipa-Caproni design was only feasible on larger aircraft. Stipa hoped that his further research would enable him to construct large aircraft powered by two to three tube-shaped engine mounts. Unfortunately for him, after a series of test flights during 1932 and 1933 the interest in his work died out. It was briefly used in various Italian aviation propaganda publications before being scrapped in 1939.
Despite being in general an unimpressive design, the French showed interest in it. Particularly the company ANF Lex Maureaux, which went so far as to acquire a license for the design in 1935. According to initial plans, a two-engine variant was to be built for testing and evaluation. The project did not go beyond basic work was later canceled.
Lastly, an interesting fact is that many people considered Stipa-Caproni to design some sort of proto-jet engine. Whether this was the case or not, Stipa felt his work was overlooked, and according to some sources, he remained bitter throughout his life until he died in the early 1990s.
Stipa hoped that with more resources he would be able to test his principle on a much larger scale, but ultimately nothing came of it. Source: L. Stipa, Stipa Monoplane with Venturi Fuselage
Replica
In 1996, aviation enthusiast Guido Zuccoli began working on a smaller replica of this aircraft. However, the death of Zuccoli in a landing accident caused a delay in the replica’s final delivery. It was finally completed in 2001 when numerous small flights were achieved. The aircraft, powered by a 72 hp Simonini racing engine, managed to achieve a flight distance of 600 m (1,968 ft). After that, the aircraft replica was stored as an exhibit at the Zuccoli Collection at Toowoomba, in Australia.
A smaller-scale replica was built and flight-tested in 2001. Source: www.uasvison.com
Conclusion
The Stipa-Caproni represented an intended for the purpose of testing his new concepts in practice. While surely an interesting and unusual concept, Stipa-Caproni’s overall design was not that practical in reality, offering little improvement over a standard aircraft design of similar dimensions.
Stipa-Caproni Specifications
Wingspans
14.3 m / 46 ft 10 in
Length
6.04 m / 19 ft 10 in
Height
3.2 m / 10 ft 7 in
Wing Area
19 m² / 204 ft²
Engine
One 120 hp (89.5 kW) De Havilland Gipsy III
Empty Weight
595 kg / lbs
Maximum Take-off Weight
850 kg / 1,874 lbs
Maximum Speed
133 km/h / 83 mph
Landing Speed
68 km/h / 42 mph
Climbing speed to 3,000 m
40 min
Maximum Service Ceiling
3,700 m / ft
Crew
1 to 2 pilots
Armament
None
Illustration
Credits
Written by Marko P.
Edited by Henry H. & Ed J.
Illustration by Godzilla
Source:
J. Thompson (1963) Italian Civil and Military Aircraft 1930-1945, Aero Publisher
R. Giacomelli, (1933) The Stipa-Caproni Monoplane, Aircraft Engineering and Aerospace Technology, Vol. 5
D. Nesic (2008) Naoružanje Drugog Svetsko Rata-Italija
L. Salari, Caproni Storia della nascitadell’ industria aeronautica
M Taylor, The Wolrd Strangest Aircraft, Metro Books
O. E. Lancaster (1959) Jet Propulsion Engines, Princeton University Press
L. Stipa (1933) Stipa Monoplane with Venturi Fuselage, Technical Memorandums Nation Advisory Committee For Aeronautics No.753
Empire of Japan (1937) Fighter Aircraft – Number Operated 30
During the war with China, the Japanese Air Forces encountered enemy fighters that were much better than what they currently had in their inventory. As their modern fighters were either under development or only available in limited numbers, they tried to acquire new fighters from aboard. The options for acquiring such fighters were rather limited, and the Japanese turned to the Germans for a solution. This came in the form of 30 He 112 known in Japanese service as the A7He1.
The He 112 in Japanese service. Source: D. Bernard Heinkel He 112 in Action
A brief He 112 history
Before the Second World War, the Luftwaffe was in need of a new and modern fighter that was to replace the older biplane fighters in service, such as the Arado Ar 68 and Heinkel He 51. For this reason, in May 1934 the RLM issued a competition for a new and modern fighter plane. While four companies responded to this request, only the designs from Heinkel and Messerschmitt were deemed sufficient. The Heinkel He 112 was a good design that offered generally acceptable flight characteristics and possessed a good basis for further improvements. The Bf 109 on the other hand had slightly better overall flight performance and was much simpler and cheaper to build. Given the fact that the Germans were attempting to accelerate the production of the new fighter, this was seen as a huge advantage over the He 112. Ultimately it would not be accepted for service, and only 100 or so aircraft would be built. These would be mainly sold abroad, with those remaining in Germany used for various testing and evaluation purposes.
While the He 112 project was canceled by the RLM, to compensate for the huge investment in resources and time into it, Heinkel was permitted to export this aircraft. A number of countries such as Austria, Japan, Romania, and Finland showed interest, but only a few actually managed to procure this aircraft, and even then, only in limited numbers.
Attempts to make a deal with Japan
In 1937 a war between Japan and China broke out. While Japan had a better-equipped and more organized army, it faced stiff resistance. The Chinese were supported by the Soviet Union which supplied them with weapons and equipment, including aircraft. These caused huge concern within the Imperial Japanese Navy. Their newest fighters were either present only in small numbers or were still under development. As a temporary solution, IJN officials decided to approach Germany for assistance in the hope of acquiring new fighters.
For this reason, a military delegation was dispatched to Germany in the Autumn of 1937. Despite its later known fame, the German Air Force at that time was still in its early stage of rebuilding and realistically did not have much to offer, being in need of modern fighters themselves. This would come in the form of the Messerschmitt Me 109. Its competing Heinkel He 112 lost the competition but was allowed to be sold abroad if anyone was interested. It was probably for this reason that the Japanese delegation visited the Heinkel factory at Marienehe. There they had the choice to observe the He 112 V9 aircraft. They were generally satisfied with what they saw and placed an initial order for 30 He 11Bs. If these proved to be as good as they hoped they would be, another, larger order for 100 more aircraft was to be given. As a confirmation of this agreement, the Japanese delegation returned with one He 112 aircraft that was to be used for familiarization and evaluation.
One of the 30 He 112 sold to Japan in 1938, Source: D. Bernard Heinkel He 112 in Action
Naming Scheme
As this aircraft was expected to enter service, it was designated as A7He1 by the IJN. The capital ‘A’ stands as a designation for a fighter. The number ‘7’ represents that this aircraft was to supersede the type 6 designation fighter. He stands for the Heinkel, and lastly the ‘1’ stands for the first variant of this type. The Allied intelligence services discovered its existence within the IJP and awarded it the code name Jerry.
Testing In Japan
Four aircraft arrived in 1937, and the last one arrived at the end of 1938. As the first aircraft began to arrive, the IJN began testing the A7He1’s performance in contrast to other fighters that they had in inventory, namely the Mitsubishi A5M2. While the A7He1 proved to be some 65 km/h faster, in other regards such as climbing speed and general maneuverability it proved equal or even worse than the Japanese fighter. The Japanese were not satisfied with the A7He1 engine which was deemed too complex. These factors ultimately led the commission which examined it to propose that it should not be adopted, nor that any further orders should be given. After the arrival of the last A7He1, the order for an additional 100 aircraft was canceled.
Ultimate Fate
As the A7He1 was not adopted for service, the IJN had to decide what to do with the 30 aircraft. They still represent a financial investment that could not be simply discarded. Some of these were allocated to various research institutes for future studies and evaluation, the remainder were given to training schools. None were ever used operationally in combat either in China or in the Pacific.
Quite surprisingly given their age and the rather limited numbers that were acquired, a few He1 survived the war and were captured by the Allies. One example was found in Atsugi airfield near Honshu in early October 1945. Unfortunately, the fate of these captured aircraft is not known but they were likely scrapped at some point after the war.
Despite the limited number of acquired aircraft, some of them survived the war and were later captured by the Allies. Source: www.destinationsjourney.comAnother aircraft (on the left) is being photographed by the Allied soldiers. It is possible that it was the same aircraft as in the previous photograph just taken later when it was being scraped. Source: www.destinationsjourney.com
Technical Characteristics
The He 112 was an all-metal single-engine fighter. The monocoque fuselage consisted of a metal base covered by riveted stress metal sheets. The wing was slightly gulled, with the wingtips bending upward, and had the same construction as the fuselage with a combination of metal construction covered in stressed metal sheets.
During its development life, a great number of engines were tested on the He 112. For the main production version, the He 112 B-2, the 700 hp Jumo 210G liquid-cooled engine was used, and some were equipped with the 680 hp Jumo 210E engine. The He 112 had a fuel capacity of 101 liters in two wing-mounted tanks, with a third 115-liter tank placed under the pilot’s seat.
The landing gear was more or less standard in design. They consisted of two larger landing wheels that retracted into the wings and one semi-retractable tail wheel. The He 112 landing gear was wide enough to provide good ground handling and stability during take-off or landing.
The cockpit received a number of modifications. Initially, it was open with a simple windshield placed in front of the pilot. Later models had a sliding canopy that was either partially or fully glazed.
While the armament was changed during the He 112’s production, the last series was equipped with two 7.92 mm MG 17 machine guns and two 2 cm Oerlikon MG FF cannons. The ammunition load for each machine gun was 500 rounds, with 60 rounds each for the cannons. If needed, two bomb racks could be placed under the wings.
Conclusion
While the He 112 was often portrayed as a modern fighter, from the Japanese point of view it proved to be disappointing in any case. While expecting a potentially effective fighter that was better with everything they had, the He 112 proved to be quite the opposite. After the 30 aircraft arrived no further orders were given. This only serves to prove that the old saying the grass is always greener on the other side is correct once in a while.
He 112B-2 Specifications
Wingspans
29 ft 10 in / 9.1 m
Length
30 ft 2 in / 9.22 m
Height
12 ft 7 in / 3.82 m
Wing Area
180 ft² / 17 m²
Engine
One 700 hp Jumo 210G liquid-cooled engine
Empty Weight
3,570 lbs / 1,620 kg
Maximum Take-off Weight
4,960 lbs / 2,250 kg
Climb Rate to 6 km
In 10 minutes
Maximum Speed
317 mph / 510 km/h
Cruising speed
300 mph / 484 km/h
Range
715 miles / 1,150 km
Maximum Service Ceiling
31,170 ft / 9,500 m
Crew
1 pilot
Armament
Two 20 mm (1.8 in) cannons and two machine guns 7.92 mm (0.31 in) machine guns and 60 kg bombs
He 112 v5 as it was tested by Japan
Credits
Written by Marko P.
Edited by Henry H.
Illustrations by Godzilla
Source:
Duško N. (2008) Naoružanje Drugog Svetsko Rata-Nemаčaka. Beograd
J. R. Smith and A. L. Kay (1990) German Aircraft of the Second World War, Putnam
D. Monday (2006) The Hamlyn Concise Guide To Axis Aircraft OF World War II, Bounty Books
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.
Independent State of Croatia (1943-1945)
Fighter – 36 to 46 Operated
During the Second World War, the German puppet state the Nezavisna Država Hrvatska NDH (Eng. Independent State of Croatia), tried to develop its own Air Force. Unfortunately for them, its German and Italian allies simply did not have the industrial resources, nor spare planes to allow them to build a significant air force. Still, the NDH’s persistence in asking for such equipment paid off in 1944 when they received over 30 captured French MS 406 fighters.
The Morane-Saulnier MS 406 in NDH service. Source: T. Likso and Danko Č. The Croatian Air Force In The Second World War
History
After Italy’s unsuccessful invasion of Greece, Benito Mussolini was forced to ask his German ally for help. Adolf Hitler agreed to assist, fearing that a possible Allied attack through the Balkans would reach Romania and its vital oil fields. In the path of the German advance towards Greece stood Yugoslavia, whose government initially agreed to join the Axis side. This agreement was short-lived, as the Yugoslav government was overthrown by an anti-Axis pro-Allied military coup at the end of March 1941. Hitler immediately gave an order for the preparation of the invasion of Yugoslavia. The war that began on 6th April 1941, sometimes called the April War, was a short one and ended with a Yugoslav defeat, and the division of its territory between the Axis powers.
With the collapse of the Kingdom of Yugoslavia, Croatia, with German aid, was finally able to declare independence, albeit becoming a fascist puppet state. It was officially formed on the 10th of April 1941. The new state received a significant territorial expansion by annexing most of western Yugoslavia, including Bosnia, parts of Serbia, and Montenegro.
While the conquest of the Kingdom of Yugoslavia proved to be an easy task for the Axis, holding these territories proved to be much more difficult. This was mainly due to two resistance movements that were actively engaged in sabotage, destroying railways and bridges, and attacking isolated occupation units’ positions and strong points. Despite attempts to suppress these attacks, the resistance movements, especially the Communist Partisans, grew rapidly, forcing the Germans and their Allies to introduce ever-larger occupation forces. The NDH forces were especially targeted as they committed mass murders and deportations to concentration camps. Thanks to the German help, they managed to form a small Air Force that in its inventory consisted of all kinds of obsolete, and in rarer cases, new equipment. By 1943, it was in the process of reorganization and the NDH officials during this time often asked their German overlords for more modern aircraft. Sometimes they even portrayed their own Air Force as weaker than it was.
The NDH Air Force was particularly poorly equipped with fighter aircraft. Luckily for them, the Germans at that time occupied what remained of Vichy France, capturing all kinds of military equipment. This also included the MS 406 fighters which was agreed to be sent to NDH by the end of 1943.
A Brief MS 406 History
At the start of the Second World War, the Morane-Saulnier MS 406 was one of the more modern French fighters built using metal components whose development began in mid-1930s. The first prototype under the designation MS 405 made its maiden test flight on the 8th of August 1935. Following successful testing and good performance, the French Ministry of Aviation issued a request for the first 50 aircraft in February 1938. Given the rising tension in Europe at that time the order was eventually increased to an additional 825 aircraft to be built. By the time, the French surrendered to the Germans over 1,000 aircraft of this type were built.
French Morane-Saulnier MS 406 fighter. Source: Wiki
The MS 406 was a good design that was nearly equal to the German Bf 109 models near the start of the war. During the War with the Germans in 1940, the MS 406 managed to achieve some success against the Germans but ultimately proved incapable of stopping the enemy. Some 300 aircraft of this type would be lost during this brief war, either due to the action of enemy fighters, ground anti-aircraft fire, or accidents. The MS 406 also achieved some success on the foreign market with 12 being sold to China, 30 to Finland, and the Swiss obtained a license for production. Poland also expressed interest in acquiring 150 aircraft of this type but nothing came of this as a result of the German invasion that began in September 1939.
In NDH service
The precise number of available MS 406 or the date when they arrived is not clear. According to A. Pelletier ( French Fighters Of World War II in Action) the NDH received 46 MS 406 in early 1943. Author V. V. Mikić ( Zrakoplovstvo Nezavisne Države Hrvatske 1941-1945) on the other hand mentioned a lower number of 38 which began to arrive at the end of 1943 and early 1944. These aircraft received registration numbers from 2301 to 2338. According to T. Likso and D. Čanak (The Croatian Air Force In Second World War) between 36 to 38 were sent to the NDH during 1944.
In late 1943, these aircraft, together with Italian-supplied Fiat G.50s, were to be used to equip the 11th Group consisting of three squadrons (21st, 22nd, and 23rd). The MS 406s were expected to arrive at the start of 1944. The first operational units were to be formed by mid-February. To help train the pilots, one Seiman 200 and ex-Yugoslav P.V.T aircraft were to be supplied. The training operations were carried out at Lučko airfield, starting from October 1943.
Once in Croatia, the MS 406 was used together with the Fiat G.50 fighter aircraft. Source: Wiki
The situation in the air and the ground significantly worsened for NDH at the start of 1944. It was especially hard-pressed as the Allies began bombing operations in occupied Yugoslavia. Thanks to their advances in Italy, they managed to set up many air bases from which these attacks could be launched. They bombed many military installations including ammunition depots, fuel production facilities, and NDH airfields.
An NDH MS 406 w heavily damaged during one of many Allied bombing attacks. The aircraft while damaged beyond repair was not written off, as it was used to cannibalize any usable spare parts. Source: T. Likso and D. Čanak The Croatian Air Force In The Second World War
On the 5th or 6th of April 1944, the Lazužani airfield where the NDH 5th Air Base was located was bombed by the Allied 2nd SAAF Squadron. They managed to completely destroy 11 and damage 20 more aircraft. One MS 406 was destroyed when an Allied bomb landed next to it. The pilot Cvitan Galić did not survive the explosion. The loss in material was such that the 23rd Lovačko Jato was disbanded. Another MS 406 was lost during a second Allied bombing run on Borongaj and Lučko air bases that occurred on the 12th of April 1944.
In March 1944 Hrvatska Zrakoplovna Legija HZL (Eng. Croatian Air Force Legion) arrived at the NDH capital Zagreb. This unit was formed way back in 1941 and was in direct control by the Germans. Its pilots participated under German controls on the Eastern Front and were quite experienced. The Germans demanded that at least two MS 406s be given to this unit to be used as training aircraft. The NDH officials could do little not to comply.
By 15th September 1944, there were 19 available MS 406 aircraft. Of this number only 7 were fully operational. On September 18th, or on the night of the 21st the sources are not clear, the Partisan forces managed to capture an NDH airfield near Banja Luka. Some 30 ,or 11 depending on the source, aircraft stationed there were captured. The NDH personnel either joined the Partisans or fled leaving behind valuable equipment and supplies. The Partisans managed to capture 3 MS 406 fighters, two were under repair. These were used against their former owners, but one was damaged in an accident and was written off.
In late 1944, the few surviving MS 406 were used in desperate attempts to stop the victorious Partisans forces that were liberating Yugoslavia from the Axis occupiers. By this point, the NDH Air Force could do little to stop them given the chronic lack of fuel. Unfortunately, the precise information about the fate of many NDH aircraft in the last few months of the war was not recorded well. While the Partisans managed to capture a few MS 406 their use was limited at best, and unfortunately, none of them is known to have survived the war.
An MS 406duirng the winter of 1944. Source: T. Likso and D. Čanak The Croatian Air Force In The Second World War
Camo and markings
The MS 406 appears to have been left in German late time war type camouflage. This usually consisted of Dunkelgrun (Eng. Dark green) and Grau (Eng. Grey) on the upper aircraft surfaces, and Hellblau (Eng. Sky Blue) on the lower surfaces. A standard Croatian white and red checkerboard coat of arms was painted on the wings and the fuselage sides. Starting from 24th February 1945 the NDH Air Force introduced the use of a black trefoil that was painted on the aircraft fuselage sides.
Near the end of the war, the NDH Air Force introduced the use of a black trefoil that was painted on the aircraft fuselage sides. Source: https://ww2aircraft.net/forum/threads/morane-saulnier-ms-406.50613/page-2
Technical Specification
The MS 406 was designed as a low-wing mix-construction fighter. Its designers went for a conventional construction aircraft design. The fuselage frame was made using aluminum tubes connected and covered with Plymax. This is a composite material that consists of layers of aluminum and plywood. The wings were constructed using a combination of spars and steel tubes also covered in this material. It was powered by one 860 hp Hispano-Suiza liquid-cooled engine. Most produced aircraft used a three-bladed two-pitch propeller, while some received variable-pitch propellers. The armament consisted of one 20 mm (0.78 in) Hispano-Suiza S9 cannon and two 7.5 mm (0.29 in) MAC 1934 machine guns. The cannon fired through the propeller shaft. The total ammunition load for the cannon was 60 and for the two machine guns 600 rounds.
Conclusion
The MS 406 was one of the few more modern fighter aircraft that was available in any significant number. But despite that, it was already obsolete and could realistically do little against Allied bombers and fighters. It was mostly used to fight the advancing Partisan formations. Few remaining aircraft were used in this role up to the end of the war.
MS 406 Specifications
Wingspans
10.6 m / 34 ft 10 in
Length
8.13 m / 26 ft 9 in
Height
2.71 m / 8 ft 10 in
Wing Area
17.1 m² / 184 ft²
Engine
One 860 hp Hispano-Suiza 12Y-31 liquid-cooled engine
Empty Weight
1,900 kg / 4,190 lbs
Maximum Take-off Weight
2,426 kg / 5,790 lbs
Climb Rate per minute
850 m / 2,790 ft
Maximum Speed
485 km/h / 302 mph
Range
1,000 km / 620 miles
Maximum Service Ceiling
9,400 m / 30,840 ft
Crew
1 pilot
Armament
One 20 mm (0.78 in) cannon and two 7.5 mm (0.29 in) machine guns
Illustration
Credits
Article written by Marko P.
Edited by Henry H.
Illustration by Godzilla
Source:
A. Pelletier (2002) French Fighters Of World War II in Action, Squadron/Signal Publication
Duško N. (2008) Naoružanje Drugog Svetsko Rata-Francuska. Beograd
V. V. Mikić, (2000) Zrakoplovstvo Nezavisne Države Hrvatske 1941-1945, Vojno istorijski institut Vojske Jugoslavije.
T. Likso and Danko Č. (1998) The Croatian Air Force In The Second World War, Nacionalna Sveučilišna Zagreb
J. R. Smith and A. L. Kay (1990) German Aircraft of the Second World War, Putnam
D. Monday (2006) The Hamlyn Concise Guide To Axis Aircraft OF World War II, Bounty Books
T.L. Morosanu and D. A. Melinte Romanian (2010) Fighter Colours 1941-1945 MMP Books
D. Bernard (1996) Heinkel He 112 in Action, Signal Publication
R.S. Hirsch, U, Feist and H. J. Nowarra (1967) Heinkel 100, 112, Aero Publisher
C. Chants (2007) Aircraft of World War II, Grange Books.
USSR (1921)
Experimental Single-seat light aircraft – 1 Prototype Built
While the Russian Civil War was raging on, there were early attempts to rebuild its shattered aviation industry. Aviation engineers and enthusiasts attempted, despite the chaos around them, to build small experimental aircraft to test their ideas and concepts. One such young individual was Andrei Nikolayevich Tupolev. His ANT-1 was a specialized design to test the concept of using metal alloys in aircraft construction.
Tupolev began his career as an aircraft engineer in 1909, when he was admitted to the Moscow Higher Technical School. There he met Professor Nikolai Yagorovich who greatly influenced Tupolev’s interest in aviation. In the following years, he spent time developing and testing various glider designs. When the First World War broke out Tupolev managed to get a job at the Russian Dux Automotive factory in Moscow, which produced a variety of goods, including aircraft. There he gained valuable experience of aircraft manufacturing.
Andrei Nikolayevich Tupolev was one of the greatest Russian/Soviet aviation engineers and designers. Source: Wiki
In 1917, the October Revolution plunged the disintegrating Russian Empire into total chaos. The few aircraft manufacturing centers were either abandoned or destroyed. All work on the design and construction of new aircraft was essentially stopped. The Dux was one exception and continued to work at a limited capacity. It was renamed to Gosudarstvennyi aviatsionnyi zavod (Eng. State aircraft factory) or simply GAZ No.1. Given that he was one of few aviation engineers left, with most skilled either being killed or fled the country, Tupolev remained working for the GAZ No.1. He spent a few years working on various projects such as designs improving weapon mounts for older aircraft that were still in service.
In 1921, Tupolev was elected as the deputy of the Aviatsii i Gidrodinamiki AGO (Eng. Aviation and Hydrodynamics Department). This department was tasked with developing various aircraft designs but also including torpedo boats. In 1921 he and his team from AGO began working on a new aircraft design that was to test new concepts. Two new innovative features were that it should be a monoplane, and be built using mainly metal alloy. Its primary purpose was not to gain any production orders, but instead to serve as a test bed for new ideas and concepts. The aircraft was named ANT-1, where ANT stands for the initials of Andrei Nikolayevich Tupovlev. This designation should not be confused with a snowmobile developed by Tupolev, which shared its name.
During this period, Soviet aviation officials and the German Junkers company spent years negotiating the possibility of producing a Duralumin alloy that could be used for aviation construction. Junkers proved the validity of this concept on the J.I saw service during the First World War. The German company wanted to avoid sanctions on arms and aviation development imposed by the Allies, while the Soviets wanted the technology for themselves, not wanting to depend on the Germans entirely. The Soviet Union in 1922, managed to produce their own copy of Duralumin known as Kol’schugaluminiyem alloy. The name was related to a small village Kol’chugino where this factory was located. Limited production of this alloy began in 1923.
Due to problems with the production of the new alloy, Tupolev was forced to postpone the development of his new aircraft until 1922. At that time the alloy was not yet available, so Tupovlev decided to go on with a standard all-wood design. The benefit of using wood was that it was an easily available material, with almost unlimited supply in Russia. It was cheap and there were plenty of skilled woodworkers. However, there were also numerous flaws in using wooden materials. The greatest issue was a generally short service life in harsh climates as in Russia, in addition, standardization of spare parts is almost impossible to do.
Tupolev himself preferred the new metal technology believing that it would offer many benefits to the aircraft industry, giving new aircraft a lighter and stronger overall construction. Tupolev eventually decided to go for a mixed-construction solution. His decision was based on a few factors, such as the general lack of this new material, and he wanted to be on the safe side as using metal in aircraft construction was still a new and not yet fully proven concept. In addition, he wanted to be sure about the Aluminum alloy material’s quality before proceeding to design a fully metal aircraft.
Once the choice for the construction material was solved the next step was to decide whether it was to be a single or two-seat configuration. The wing design was also greatly considered. After some time spent in calculations and small wind testing, the choice was made to proceed with a single engine and low-wing monoplane.
For the engine, three different types were proposed including 14hp and 18 hp Harley-Davidson and a 20 hp Blackburn Tomtit. Despite Tupovlev’s attempts, he failed to acquire any one of these three. It was not until early 1923 that he managed to get his hands on an old 35hp Anzani engine which was over 10 years old by that point. Despite its poor mechanical state, Tupovlev knowing that nothing else was available decided to try salvage it.
Testing and the Final Fate
The construction of this aircraft took over a year to complete. Given the general chaos at that time, this should not be surprising. It was finally completed in October 1923, and the first test flight was carried out on the 21st of October of the same year. Despite using the older engine, the flight proved successful. It was piloted by Yevgeni Pogosski.
The completed ANT-1 test aircraft. Source: www.globalsecurity.org
Following this, the ANT-1 was used mainly for various testing and evaluation. It would see service in this manner for the next two years. In 1925 the aging engine finally gave up, and this made the aircraft unflyable. Tupovlev tried to find a factory that could potentially refurbish it. He ultimately failed, as the engine was simply beyond repair by that point.
The aircraft was for some time stored at Factory No.156. The fate of this aircraft is not clear in the sources, however, there are few theories about what happened to it. After Tupovlev’s imprisonment by Josef Stalin, his plans and documentation were confiscated. The aircraft was believed to be also confiscated and scrapped in the late 1930s. Another possibility is that it was moved to another storage facility where it was eventually lost during the Axis Invasion of the Soviet Union in 1941.
Specification
The ANT-1 was designed as a cantilever low-wing monoplane aircraft of mixed construction. The fuselage consisted of four spruce longerons. The lower two were connected to the wing spars and were held in place with four bolts. The parts of the fuselage starting with the pilot cockpit to the engine were covered in the metal alloy. This alloy was also used to provide additional strength of some internal wooden components of the aircraft fuselage. The pilot Pilot cockpit was provided with a small windscreen. Inboard equipment was spartan consisting only of an rpm counter, oil pressure indicator, and ignition switch.
The cantilever wings were made of single pieces. At the end of the two tips (on each side of the wings) large wooden spars were installed. Some parts of the wing were built using metal parts such as the wing ribs, The rest of the wing was mainly covered in fabric. The tail unit was made of wood, its surfaces were covered with a metal-fabric cover.
The fixed landing gear consisted of two large wheels. These were connected to a metal frame which itself was connected to the aircraft fuselage. Small rubber bungees acted as primitive shock absorbers.
Given that nothing else was available, the ANT-1 was powered by an old, refurbished 35-hp strong Bristol Anzani engine.
A good view of the ANT-1 internal wing and fuselage construction. Source: www.globalsecurity.orgThe cantilever wings received on each side one large wooden spar. Source: WikiThe pilot cockpit received only a few basic instruments and a small windshield. Source:www.globalsecurity.org
Conclusion
The ANT-1 despite its simplicity, and being built a single, cobbled-together prototype, could be considered a great success for Tupolev. Through this experimental aircraft, Tupovlev gained valuable experience in designing an aircraft by using metal alloy. This success emboldened Tupovlev to go even further and design and build the Soviet first all-metal construction aircraft known as ANT-2. The ANT-1 was Tupovlev’s first stepping stone in a long and successful career as an aircraft designer in the following decades.
ANT-1 Specifications
Wingspans
7.2 m / 23ft 7 in
Length
5.4 m / 17 ft 8 in
Height
1.7 m / 5 ft 7 in
Wing Area
10 m² / 108 ft²
Engine
One 35 hp Bristol Anzani engine
Empty Weight
230 kg / 5,070 lb
Maximum Takeoff Weight
360 kg / 7,940 lb
Maximum Speed
125 km/h / 78 mp/h
Range
400 km / 250 miles
Maximum Service Ceiling
600 m / 1,970 ft
Maximum Theoretical Service Ceiling
4,000 m / 13,120 ft
Crew
1 pilot
Armament
None
Gallery
Credits
Article written by Marko P.
Edited by Henry H.
Illustration by Godzilla
Sources:
Duško N. (2008) Naoružanje Drugog Svetsko Rata-SSSR. Beograd.
Y. Gordon and V. Rigmant (2005) OKB Tupolev, Midland
P. Duffy and A. Kandalov (1996) Tupolev The Man and His Aircraft, SAE International
B. Gunston () Tupolev Aircraft Since 1922, Naval Institute press
Twin-engined fighter-bombert Number built: 114 plus two prototypes
In the history of aviation, small production numbers usually indicated that a particular aircraft did not meet the desired results, or was simply a bad design. However, there were designs that performed well in their designated roles, but still built in few numbers. In such cases, external factors were usually to blame for that aircraft’s downfall. These were typically connected to production difficulties, such as the unavailability, or the unreliability of components. This was the case with the UK Westland Whirlwind, a twin-engined fighter that despite its excellent performance, failed due to engine supply issues, and was built in limited numbers.
The Westland Whirlwind twin-engined day and night fighter. Source: Wiki
History
The 1930s saw the United Kingdom Royal Air Force’s extensive adoption of new technologies. Improvements in fuselage design, new materials, heavier armaments, and more powerful engines were key in this period. These allowed for the development of faster, harder-hitting fighters than those previously in service. At that time, the fighter force of the RAF consisted of biplanes such as the Bristol Bulldog, for example. These were becoming obsolete in regard to speed of and offensive armament. In 1934, the development of much better low-wing fighters was initiated by the Air Ministry. These would evolve into the well-known Hurricane and Spitfire fighters. Such aircraft were armed with licensed 7.62 mm (0.3 in) Browning machine guns, but something with a heavier punch was also considered. For this purpose, the French Hispano-Suiza company was contacted. This company produced the well-known 20mm (0.78 in) Hispano cannon. A license was acquired and these cannons would be built by the BSA company. The delivery of new guns was carried out at a slow pace, and it was not produced in great quantities up to 1942. With the acquisition of a sufficiently strong armament and the availability of more powerful engines, the Air Ministry issued a request for more heavily armed twin-engined aircraft designs. This included the single and a two-seat day and night fighter configuration.
The final specifications for such aircraft were issued in 1936. The principal concept of this new aircraft was to focus a strong armament of four 20mm cannons inside of the aircraft nose. Several companies responded to these requests. The Air Ministry was mostly satisfied with the work of the Bristol, Supermarine, and Westland companies.
Westland Aircraft Ltd., was a relatively new, but successful aircraft manufacturer in mid-1930, and they were highly interested in the new twin-engine fighter project. For this, a team was gathered under the leadership of was designed by W.E.W. Petter. The project was initially designated as P.9, “P” stands for Petter but has nothing to do with its chief designer, and was presented to the Air Ministry. The following year the Westland project was deemed the best design and given the green light. Orders for the construction of two prototypes were issued, initially designated L6844 and L6845, in February 1937. The first wind-tunnel tests showed that some changes were needed regarding the model tail assembly due to longitudinal control problems. The Whirlwind was initially to have a twin rudder and fins configuration, but this was changed to a high-set tailplane to solve the problem. In May 1937 the first mock-up was completed. As it was deemed sufficient, work on the first prototype began shortly after its unveiling. Due to delivery problems, this aircraft could not be completed until October 1938.
The first prototype during its early testing phase. Source: M. Ovcacik and K. Susa Westland Whirlwind
At that time, the project was officially designated as Whirlwind. The same month, the first ground test was completed, and shortly after that the maiden flight was made. The aircraft was flight-tested by Westland’s own chief pilot Harald Penrose. Following that, it was allocated to the Royal Aircraft Establishment at Farnborough for future testing.
During this early testing stage, numerous problems were encountered. The engine was somewhat problematic as it was prone to overheating. Another major problem was poor directional stability during flight. This was solved by increasing the rudder area at the tailplanes. In addition, the engineers added a concave-shaped surface on the rudders. To further stabilize the aircraft during stall and dives, an oval-shaped extension was added at the connection point of the vertical and horizontal stabilizers.
With these modifications, the flight testing of the first prototype continued into 1939. At that time the work on the second prototype was nearing completion. It would be tested with engines that rotated in the same direction. As this did not affect its overall performance, it made the production slightly easier. As both prototypes performed well, a production order of 200 aircraft was placed at the start of 1939.
However, precise specifications needed for production were not made until May 1939. The delay was caused by the indecisiveness regarding which engine to use, during this period various proposals were made. Further tests showed problems with exhaust systems, which had to be replaced with simpler designs. The overheating problems led to the redesigning of the pressurized cooling system.
The second prototype aircraft. Source: Wiki
As there were no available 20mm cannons, the prototypes were initially not fitted with any offensive armament. Once these were available, they would be fitted on both prototypes. Additional firing trials were to be carried out. These were to test various other proposed armaments
Following the successful testing of the first prototype, it would be allocated to the No.4 School of Technical Training. The second prototype would be allocated to RAF No. 25 Squadron In June 1940. It would remain there until it was damaged in an accident and removed from service in June 1941.
Despite the whole project being undertaken in secrecy, both Germany and France were aware of its existence. The French even published technical papers mentioning this aircraft, with the Germans publishing their own in 1940. However, in Britain, the existence of this aircraft was only publicly announced in 1942.
Production
The production of the Whirlwind was delayed due to a lack of engines up to May 1940. The fighter versions that slowly began to be issued for operational use were designated Whirlwind MK. I. The production version was slightly different from the prototypes. The mudguards on the landing wheels were removed and the exhaust was modified. Some other changes would be implemented during its production, such as moving the position of the radio mast. Initially, it was positioned on the sliding hood but later it would be moved further forward. Beyond that, the cockpit underwent a minor redesign. There were plans to adopt this fighter for service in other parts of the British Empire, but this request was never implemented.
As the production was slowly going on, another order for 200 more aircraft was placed in 1939. But this production quota would be canceled at the end of 1940. The Air Ministry limited the production of this aircraft to only 114 examples. The reasons for these limited production numbers were a general lack of Peregrine engines. These engines were actually being phased out of production in favor of more powerful engines, namely the Rolls Royce Merlin. The last aircraft was completed in December of 1941 or January 1942 depending on the source. Production was carried out at the newly built factories at Yeovil.
Service
Given their small production numbers, it should not come as a surprise that the distribution of this aircraft to frontline units was limited. The first three operational aircraft were allocated to No.25 Squadron stationed at North Weald. These were only briefly used by this unit from June to mid-July 1940. It was decided to instead re-equip the unit with the Beaufighter Mk. IF. The RAF’s No.263 squadron stationed at Grangemouth was next to be supplied with the Whirlwinds. The deliveries of the first aircraft were scheduled to arrive in July 1940. On the 7th of August, an accident occurred where one aircraft was lost. During a take-off, one of the tires blew out damaging the loading gear. Despite this, the pilot managed to retain control and fly off the aircraft away from the airstrip. Once in the air, he was informed of the damage sustained during the take-off. The pilot at that point had two options, either to try a hard landing and hope to survive or to simply bail out of the aircraft and use his parachute. The pilot chose the latter option, while the aircraft was completely lost, the pilot was unharmed. Due to slow delivery, only 8 aircraft were received by this unit by October 1940. At the end of that year, the unit was repositioned to Exeter. The first combat action occurred on the 12th of January 1941. One aircraft took off and tried to engage returning German bombers. After a brief skirmish, one German Ju 88 was reported to be damaged. The first air victory was achieved a month later when a Whirlwind managed to shoot down an Arado 196 near Dodman Point.
In March, some 9 out of 12 operational Whirlwinds would be damaged in one of many German air raids. For this reason, the unit was moved to Portreath and then to Filton. During this period the unit suffered further casualties, of which three were in action while the majority were lost during accidents.
On the 14th of June, some 6 aircraft were used in ground attack operations against German airfields at the Cherbourg peninsula. Due to bad weather, the attack was rather unsuccessful. In August, this squadron was repositioned to Charmy Down. From this base it flaw several escort missions. The same month several air raids against enemy air bases were also undertaken. These were successful, with the Whirlwinds managing to destroy many enemy aircraft on the ground. These included: three Ju 88s, possibly up to eight Ju 87s, and a few Bf 109s. Interestingly, even one German submarine was reportedly destroyed.
On a few occasions, enemy aircraft were engaged in the air. During one air clash, some 20 Bf 109s engaged a group of four Whirlwinds. In the following skirmish, the Germans lost two fighters. The British had two damaged aircraft, with one more being lost after a forced landing due to damage sustained during this fight.
No.137 squadron was another operational unit that had some Whirlwinds in its inventory. It was fully operational starting from October 1941 when it was stationed at Charmy Down. This unit was formed with the assistance of the previously mentioned squadron which provided experienced pilots and ground crew. One of the first combat actions of this unit occurred in February 1942. During an engagement with German Bf 109 fighters, this unit lost four Whirlwinds. Both units would continue to operate the Whirlwinds in various combat missions, which usually involved attacking ground targets and facilities, either along the English Channel or in Western parts of occupied Europe.
With its four 2 cm cannon armament this aircraft possesses quite strong firepower. Source: WikiGiven their limited numbers, only two squadrons would be ever equipped with this type of aircraft during the war. Source: Wiki
Fighter-Bomber Adaptation
While the armament of four cannons offered strong offensive capabilities, a bomb load would expand the air-to-ground capabilities of the plane even further. Such rearmament was proposed in September 1941 by T. Pugh, one of the squadron leaders. Given their limited number and the urgency of other projects, the first tests were not carried out until July 1942. One aircraft was modified at the Aeroplane and Armament Experimental Establishment to be able to carry either 113 kg (250 lb) or 226kg (500 lb) bombs placed beneath the outer wings. The results were positive and mechanics from the No.263 squadron began adding the bomb bracket on the wings starting from August 1942. No.137 squadron followed up soon with the same modifications. While no official designations were issued for these modifications, the units that used them referred to them as Whirlibombers. In total, some 67 such modifications would be carried out.
The first combat action of these modified aircraft occurred on the 9th of September 1942. The British launched an attack on German trawler ships near Cherbourg. These aircraft would see extensive use up to 1943 against various ground targets. Trains were a common target, with some 67 being destroyed.
With the addition of bombs the firepower of this aircraft was greatly boosted. Source: www.staplesandvine.comClose-up view of the bomb release mechanism. Source: Pinterest
Whirlwind Mk.II Project
While having a good overall design, the Whirlwinds had a few shortcomings. While having excellent flight performance at low altitudes, at greater heights its performance dropped sharply. The main reason for this was that its Peregrine engines used a small, single-stage, single-gear supercharger, and the small engine lost a considerable amount of power in thinner air. But there were some attempts made to further improve its performance, designated as Mk.II. The main drawback of the whole design was the engines, which while good had the potential to be further improved, and they were quite underpowered compared to the Rolls Royce Merlin engines. In 1940 it was proposed to use stronger Peregrine engines, a modified armament, and an increased fuel load. The armament would have consisted of four 2 cm Hispano Mk.II cannons which were belt-fed. While the fuel load would be increased by 42 gallons. Given that the main producer of engines, Rolls-Royce, was focusing all available resources on Merlin engine production there was simply no room for other projects. Thus the Air Ministry would simply abandon plans to further improve this aircraft.
Final Fate
All produced aircraft would be only used by these two units. Eventually, due to limited production numbers, and the wear of equipment, they were relegated to limited service. No.137 squadron retained its Whirlwinds up to June 1943 before they were replaced with Hurricane Mk.IVs. The other unit operated them a bit longer, until the end of the year. These would be replaced with the Hawker Typhoon. The surviving aircraft were gathered at various maintenance depots before finally being declared obsolete and scrapped in late 1944. Only one aircraft survived the war. It remained in service up to 1947 before it too was scrapped.
Limited Export Service
As very few aircraft were produced, there was little prospect of them being exported to other Allied nations. An exception would be one aircraft (P6994) which was shipped to America in June 1942. There it was likely used for evaluation and testing, but its history or fate is unknown.
Technical characteristics
The Whirlwind was designed as a twin-engined low-wing, all-metal, day and night fighter. Despite being originally intended for this double role, it was never used in night operations. The fuselage was oval-shaped and consisted of 17 metal formers that were connected together. The front sections were built using aluminum while the rear part used magnesium alloy. The nose is where the main armament was located, along with a 9 mm thick armor plate to protect the pilot.
The tail assembly had the same construction. Which consisted of a metal frame covered in duralumin sheeting. But if in need of repairs, the whole rear section could be removed. As mentioned the horizontal stabilizers had to be moved further up the fin. An interesting feature of this aircraft was the two-part rudder. Initial testing showed that they were quite ineffective during take-off. For this reason, they were replaced with new ones that were concave,on both sides, in shape.
The wings were constructed using metal frame ribs. These were then covered with duralumin sheeting which was flush riveted. Several various sizes of access panels were added to help the ground repair crew during the maintenance or replacement of damaged parts of the wings. The ailerons were also covered in metal. These were provided with trimming tabs which could be adjusted when the aircraft was on the ground. The wings on this aircraft incorporated the two-engine nacelles. These fairly large, but aerodynamically well-shaped nacelles were used to store the engine, fuel, and oil pumps that the front landing gear units. A highly interesting design decision was to add coolant radiators which were located on the central part of the wing trailing edges. This allows them to reduce the drag as much as possible.
Behind the aircraft’s nose, the cockpit was located. It had a large canopy which provided an excellent all-around view for the pilot. Given the offensive role of the aircraft, the pilot was fairly well protected. To the front, a 9 mm armor plate was positioned. While on the rear and lower parts of the seat were protected by a 6 and 4-mm thick armor plate. The cockpit itself was connected to the main fuselage by using bolts. The front part of the canopy was protected by bullet-resistant laminated glass. Under and behind the cockpit various equipment was stored. This included a radio unit, de-icing tanks, accumulators, exigent tanks, etc. To have easy access to some of these a small hatch was installed on the right side of the rear fuselage.
The Whirlwind was designed as a twin-engined low-wing all-metal day and night fighter. Some of the easily recognizable features were the enlarged glazed cockpit and the positions of the tail horizontal stabilizers. Source: Wiki
The landing gear consisted of two wing-mounted retractable wheels. With one smaller tailwheel placed. To provide a smoother landing, the front landing gear units used a pair of heavy shock absorbers. These use 790 x 270 mm (31 in x 10 in) Dunlop-type wheels. All three landing gear units retracted to the rear. The two larger wheels retracted into the engine nacelles. The lowering or retracting of the landing gear was controlled by the pilot by using a lever.
This aircraft was powered by two compact, 880 hp Rolls-Royce Peregrine I engines. These were actually fairly underpowered, they weighed about as much as a Merlin but were significantly less powerful. It’s a major reason this plane wasn’t retained, they simply couldn’t upgrade it with a better, but larger engine. These two engines were provided with a 25 cm (10 in) diameter thick de Havilland three-bladed with variable pitch propellers. This engine was electrically started. The engine was seated on a specially designed mount which consisted of two bearers and bracing tubes. The engine, while enclosed, was provided with several small hatch access points for repair and maintenance. Fuel was supplied to the engine using two separate systems of power by pumps. The fuel was stored inside two tanks located in each wing. These were encased in a duralumin shell. To avoid spilling the fuel inside the aircraft, a self-sealing covering was also used. The total fuel capacity was 609 liters (134 gallons).
This aircraft was powered by two Rolls-Royce Peregrine engines. The lack of this engine ultimately leads to the abandonment of the whole project. Source: dingeraviation.net
The main armament of this type consisted of four 2 cm Hispano Mk.I type 404 cannons. These were mounted in pairs and located in the front aircraft nose. Its ammunition load consisted of 60 rounds per gun set in large drum magazines. Before the aircraft was to fly into action the Hispano cannons had to be manually cocked while still on the ground. Initially, a hydraulic firing mechanism was used. It would be replaced later in the production by a pneumatic firing system.
Besides the use of four cannons various other armament installations were also proposed or tested. For example, a redesigned nose mounting that consisted of 12 Browning machine guns was tested. Another experimental mount consisted of four vertically positioned cannons and three machine guns. Additional tests were carried out with larger 3.7 cm and 4 cm guns. The plans of using two 4 cm guns were quickly discarded as it would require extensive rework of the aircraft design. In 1942 attempts were made to add two machine guns for self-defense but this was abandoned too.
Once the nose cover was removed we can clearly see the arrangement of the four 2 cm Hispano Mk.I type 404 cannons. The ground crew member to the left is holding the 60-round drum magazine. Source: /dingeraviation.net
Other experimental proposals included adding 12 machine guns. Source: M. Ovcacik and K. Susa Westland WhirlwindWhile this proposal included four horizontally positioned cannons and three more machine guns. In either case, none of these would be adopted. Source: M. Ovcacik and K. Susa Westland Whirlwind
Production Versions
Two Prototypes – Both used for varius testing and evaluation with one being lost in an accident
Mk. I Fighter-bomber – over 60 aircraft were armed with bombs
Mk.II – Proposed improved versions, none built
Operators
UK – The only operator of these aircraft
USA – One Aircraft was shipped to America for testing and evaluation, but its fate is unknown
Westland Whirlwind Reconstruction
The completed pilot cockpit and the armament are located at the Kent Battle of Britain Museum. Source: https://www.whirlwindfp.org/
Conclusion
The Westland Whirlwind was a quite advanced twin-engined fighter design for its day. Although initially designed as a day and night fighter, it would never fully be used in this role due to problems with the acquisition of stronger engines and limited production run. Thanks to its strong armament it saw combat service as a ground attack aircraft with good results.
But despite its performance, the lack of sufficiently strong engines and general lack of vision for this aircraft ultimately killed the project. It was more a case that the aircraft was built around an engine that just wasn’t very good, and it couldn’t accept the larger, but much more powerful Merlin engine.
Westland Whirlwind Specifications
Wingspans
13.7 m / 45 ft
Length
9.8 m / 32 ft 3 in
Height
4.9 m / 16 ft 3 in
Wing Area
23.23 m² / 250 ft²
Engine
Two 880 hp Rolls Royce Peregrine inline piston engine
Empty Weight
3.770 kg /8.310 lb
Maximum Takeoff Weight
5.180 kg /11.410 lb
Climb Rate to 6.1 km
In 8 minutes
Maximum Speed
580 km/h / 360 mph
Diving speed
645 km/h / 400 mph
Range
1,115 km / 630 miles
Maximum Service Ceiling
9.240 m / 30.300 ft
Crew
1 pilot
Armament
Four 2 cm ( 0.78in) cannons
Payload of 454 kg (1,000 lb kg) bombs
Credits
Article written by Marko P.
Edited by Henry H.
Ported by Marko P.
Illustrated By Godzilla
Illustrations
Whirlwind in the Battle of Britain era camouflage scheme.Whirlwind in the 1942/43 livery
Source:
M. Ovcacik and K. Susa (2002) Westland Whirlwind, 4+ Publication
D. Monday (1994) British Aircraft Of World War II, Chancellor Press
Duško N. (2008) Naoružanje Drugog Svetsko Rata-.Beograd
P. J. R. Moyes The Westland Whirlwind, Profile Publication
Kingdom of Hungary (1938)
Fighter Aircraft – 4 aircraft operated
Despite being not adopted for service by the German Luftwaffe, the He 112 had great potential as an export aircraft. Spain, Romania, and Japan were some of the countries that got their hands on fighter aircraft. Hungary, with its close ties to Germany, also wanted this fighter in its inventory, though it was not to be. Unfortunately for them, despite their efforts, only a few of these aircraft would ever see service with their Air Force. This was mainly due to the reluctance of Germany to provide the necessary parts and licenses, and the start of the Second World War. The few aircraft that did reach Hungary were mainly used for crew training and even saw limited combat use.
Prior to the Second World War, the Luftwaffe was in need of a new and modern fighter to replace the older biplanes that were in service, such as the Arado Ar 68 and Heinkel He 51. For this reason, in May 1934, the RLM issued a competition for a new, modern fighter plane. While four companies responded to this request, only the designs from Heinkel and Messerschmitt were deemed sufficient. The Heinkel He 112 was a good design that offered generally acceptable flight characteristics and possessed a good foundation for further improvements. The Bf 109 on the other hand, had slightly better overall flight performance and was much simpler and cheaper to build. Given the fact that the Germans were attempting to accelerate the production of the new fighter, that alone was seen as a huge advantage over the He 112. Ultimately it would not be accepted for service, and only 100 or so aircraft would be built. These would be mainly sold abroad, with those remaining in Germany being used for various testing and evaluation purposes.
While the He 112 project was canceled by the RLM, to compensate for the huge investment in resources, Heinkel was permitted to export this aircraft. A number of countries such as Austria, Japan, Romania, and Finland showed interest, but only a few actually managed to procure this aircraft, and even then, only in limited numbers.
Hungarian Interest in the He 112
Being that it was on the losing side of the First World War, the Hungarians were in a similar situation to Germany in regard to military restrictions under the Treaty of Versailles. Crucially, it prohibited the Hungarians from developing their air forces. In time though, the Allies became less and less involved in maintaining the Treaty, and the Hungarians began slowly rebuilding their air force. By 1938 the Magyar Királyi Honvéd Légierő MKHL (English: Royal Hungarian Home Defence Air Force) was openly presented to the world. At that time, the Hungarians undertook steps to rebuild their armed forces in the hope of reclaiming some of their lost territories. For a modern air force, they needed better fighter designs, as their aged biplanes would not be sufficient. By 1938, they had improved their relations with Germany, and it was then possible to acquire new equipment from them.
The Hungarian military delegation that was in Spain during the civil war observed the relatively new Heinkel He 112 fighter in action and immediately became interested in it. In June 1938, a military group disguised as a civilian delegation visited Heinkel’s company. Three Hungarian pilots had the chance to flight test the He 112V9 aircraft. They were highly impressed and urged the Hungarian Army officials to adopt this aircraft. Unsurprisingly, based on the glowing report, the Hadügyminisztérium (Ministry of War Affairs) asked Heinkel for 36 such aircraft.
Unfortunately for them, Heinkel never actually put the He 112 into mass production, given the fact that it was not adopted for service with the German Air Force. It did, however, build a small series that was intended for Spain and Japan. The Hungarian offer was not considered as important, and thus no aircraft would be delivered to them. The Reichsluftfahrtministerium RLM (English: German Ministry of Aviation) also intentionally delayed the delivery of weapons to Hungary. This was done to politically and economically pressure the Hungarians and Romanians who were on the brink of war at that time, in an attempt to reduce tensions.
Still, the Hungarians persisted, and at the start of 1939, they requested again for the 36 aircraft, and once again, the Germans denied this request. However, a single He 112 V9 was given to Hungary and was used for flight testing near Budapest. On the 5th of February 1939, it crashed during a test flight against a CR-32 biplane fighter. In March 1939, another aircraft was sent to Hungary, this one being a He 112 B-1. It was extensively tested by the Hungarians who generally liked its design.
The He 112 V9 was lost in an accident during its first test flight. Source: D. Bernard Heinkel He 112 in Action
As the Romanians acquired a batch of 24 He 112 In 1939, the Hungarians were concerned over their neighbor’s growing military strength. Realizing that the Germans would not deliver the promised aircraft, they decided to ask for a production license instead. This was granted, and Heinkel also delivered two more He 112 B-1 with the Jumo 210E engine. When the license document arrived in Hungary in May 1939, a production order for the 12 first aircraft was given to the Weiss Manfréd aircraft manufacturer. Several changes were made, including the installation of 8 mm 39.M machine guns and the addition of bombing racks. In addition, the original 2 cm cannons were to be replaced by the Hungarian, domestically built, Danuvla 39, though it is unclear if any were actually installed. As the preparation for the production was underway the three available He 112 were adopted to service. This received coded designation V.301 to 303 where the V stands for Vadász (English: Fighter).
The B-series was in many aspects a complete redesign of the previous series. Including the introduction of a new tail unit, and part of the fuselage, to name a few. Source: www.luftwaffephotos.com
Despite the best Hungarian attempts to put the He 112 in production, the situation was made impossible by the coming war between Poland and Germany. The RLM would officially prohibit the export of any German aircraft engines and equipment at the start of the war. This meant that the vital delivery of the Jumo 210 and DB 601 engines could not be made. Based on this fact, all work on the Hungarian He 112 was canceled. Instead, Weiss Manfréd investigated to see if it could reuse most of the He 112 production line to produce a new domestic design named WM–23 Ezüst Nyíl(English: Silver arrow). While one prototype was built it was lost in an accident which ended the project.
The WM–23 Ezüst Nyíl prototype. Source: www.destinationsjourney.comThe V.303 during pilot training in 1940. Source: www.destinationsjourney.comDespite their best efforts, the Hungarians managed to operate only three He 112 (not including the single aircraft last way back in Budapest) Source: www.destinationsjourney.com
In Combat
In the Summer of 1940, the rising tension between Romania and Hungary over Transylvania reached a critical point. Transylvania was once part of Hungary but was lost after the First World War when it was given to Romania. By 1940, the Hungarian Army began preparing for a possible war with Romania over the territory. As neither side was willing to enter a hastily prepared war, negotiations began to find a possible solution. But despite this, there were some minor skirmishes, and Hungarian aircraft made several reconnaissance flights over Romania. The three Hungarian He 112 were stationed near the border, and the Romanians also had some He 112 in their inventory. While the Hungarian He 112’s did take up to the sky, no combat action by them was reported. Ultimately, at the end of August, Romania asked Germany to arbitrate the issue regarding the disputed territory, With Hungary being given the northern part of Transylvania in the settlement.
During the Axis invasion of Yugoslavia in April 1940, Hungary once again mobilized its He 112s. These were stationed near the border with Yugoslavia but they were not used in any combat operations.
By the time the Axis attacked the Soviet Union in June 1941 all three He 112 were used as training aircraft, with their secondary role being to protect the Weiss Manfréd factory. Due to a lack of spare parts, there was no point in sending this aircraft to the frontline. Two aircraft were involved in a landing accident where they were damaged. While their final fate is not completely clear, they may have been destroyed in 1944 when the Allies intensified their bombing campaign against Hungary. It is unlikely that the He 112s were operational at this point.
The V.301 had an accident where the pilot forgot to activate the landing gear. This is not surprising given that most pilots at that time mainly flaw on the older biplanes that had fixed landing gear. Source: www.destinationsjourney.comIn the Summer of 1941 the V.303 was damaged during a landing where the left landing gear wheel simply broke off. Source: www.destinationsjourney.com
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, but otherwise had a conventional construction.
During its development life, a great number of different engines were tested on the He 112. For the main production version, the He 112 B-2, it carried a 700 hp Jumo 210G liquid-cooled engine, with some others being equipped with the 680 hp Jumo 210E engine. The He 112 had a fuel capacity of 101 liters in two wing-mounted tanks, with a third 115-liter tank placed under the pilot’s seat.
The landing gear was more or less standard in design. It consisted of two larger landing wheels that retracted into the wings and one semi-retractable tail wheel. The He 112 landing gear was wide enough to provide good ground handling and stability during take-off or landing.
The cockpit received a number of modifications. Initially, it was open with a simple windshield placed in front of the pilot, with Later models having a sliding canopy.
The armament was changed throughout the He 112’s production, and the last series was equipped with two 7.92 mm MG 17 machine guns and two 2 cm MG FF cannons. The ammunition load for each machine gun was 500, with 60 rounds for each of the cannons. If needed, two bomb racks could be placed under the wings.
Conclusion
The He 112, although few in number, provided the Hungarian Air Force with one of its first modern fighter aircraft. Despite the Hungarian attempts to acquire over 30 aircraft from Germany, this was never achieved. In the end, the Hungarians only had three operational He 112, and one was lost in an accident during testing. While these were stationed on the front line on two occasions they never saw actual combat action. By 1941 due to a lack of spare parts, they were allocated for training purposes. The Hungarians eventually got a production license for the Messerschmitt Bf 109G making the few available He 112 unnecessary.
He 112B-1 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 r 680 hp Jumo 210E liquid-cooled engine
Empty Weight
3,570 lbs / 1,620 kg
Maximum Take-off Weight
4,960 lbs / 2,250 kg
Climb Rate to 6 km
In 10 minutes
Maximum Speed
317 mph / 510 km/h
Cruising speed
300 mph / 484 km/h
Range
715 miles / 1,150 km
Maximum Service Ceiling
31,170 ft / 9,500 m
Crew
1 pilot
Armament
Two 20 mm (1.8 in) cannons and two machine guns 8 mm (0.31 in) machine guns and 60 kg bombs
Credits
Article written by Marko P.
Edited by Henry H.
Ported by Marko P.
Illustrated By Godzilla
Illustrations
Source:
Duško N. (2008) Naoružanje Drugog Svetsko Rata-Nemаčaka. Beograd
G. Punka (1994) Hungarian Air Force, Squadron Publication
J. R. Smith and A. L. Kay (1990) German Aircraft of the Second World War, Putnam
D. Monday (2006) The Hamlyn Concise Guide To Axis Aircraft OF World War II, Bounty Books
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
S. Renner. (2016) Broken Wings The Hungarian Air Force, 1918-45, Indiana University Press
In the later stages of the Second World War, it was becoming apparent to both the Luftwaffe (English German Air Force) and the German Government that the Allied air forces were gaining air superiority. This realization saw them turn to new and fantastical ideas in a desperate attempt to turn the tide of the war. Some of these represented new improvements to existing designs, the introduction of the newly developed turbojet engine, and even more esoteric and experimental methods. In many cases, these were pure fantasies, unrealistic or desperate designs with no hope of success. Few of them reached any significant development, and among them were the works of Alexander Martin Lippisch. While Lippisch helped develop the Me 163, the first rocket-powered interceptor, his other work remained mostly theoretical. One such project was the unusual P 13a, ramjet-powered aircraft that was to use coal as its main fuel source. While some work was carried out late in the war and soon faced insurmountable technical problems, thus nothing came of the project.
Artistic presentation of how the P 13a may have looked. Source: Luftwaffe Secret Jets of the Third Reich
History
Before the start of the Second World War, aviation enthusiast and engineer Alexander Martin Lippisch, was fascinated with tailless delta wing designs. Lippisch’s early work primarily involved the development of experimental gliders. Eventually, he made a breakthrough at the Deutsche Forschungsinstitut, where he worked as an engineer. His work at DFS would lead to the creation of the rocket-powered glider known as the DFS 194. As this design was a promising experiment in a new field, it was moved to Messerschmitt’s facility at Augsburg. After some time spent refining this design, it eventually led to the development of the Me 163 rocket-powered interceptor. While it was a relatively cheap aircraft, it could never be mass-produced, mostly due to difficulties associated with its highly volatile fuel. In 1942, Lippisch left Messerschmitt and ceased work on the Me 163 project. Instead, he joined the Luftfahrtforschungsanstalt Wien (English: Aeronautic Research Institute in Vienna) where he continued working on his delta-wing aircraft designs. In May 1943 he became director of this institution, and at that time the work on a supersonic aircraft was initiated.
In the later war years, among the many issues facing the Luftwaffe, was a chronic fuel shortage. Lippisch and his team wanted to overcome this problem by introducing alternative fuels for their aircraft. Luckily for his team, DFS was testing a new ramjet engine. They were designed to compress air which would be mixed with fuel to create thrust but without a mechanical compressor. While this is, at least in theory, much simpler to build than a standard jet engine, it can not function during take-off as it requires a high airflow through it to function. Thus, an auxiliary power plant was needed. It should, however, be noted that this was not new technology and had existed since 1913, when a French engineer by the name of Rene Lorin patented such an engine. Due to a lack of necessary materials, it was not possible to build a fully operational prototype at that time, and it would take decades before a proper ramjet could be completed. In Germany, work on such engines was mostly carried out by Hellmuth Walter during the 1930s. While his initial work was promising, he eventually gave up on its development and switched to a rocket engine instead. The first working prototype was built and tested by the German Research Center for Gliding in 1942. It was later tested by mounting the engine on a Dornier Do 17 and, later, a Dornier Do 217.
The Dornier Do 217 was equipped with experimental ramjets during trials. Source: tanks45.tripod.com
In October 1943, Lippisch won a contract to develop the experimental P 11 delta-wing aircraft. While developing this aircraft, Lippisch became interested in merging his new work with a ramjet engine. This would lead to the creation of a new project named the P 12. In the early stage of the project, Lippisch and his team were not completely sure what to use as fuel for their aircraft, but ramjets could be adapted to use other types of fuel beyond aviation gasoline.
Unfortunately for them, LFW’s facilities were heavily damaged in the Allied bombing raids in June 1944. In addition to the damage to the project itself, over 45 team members died during this raid. To further complicate matters, the scarcity of gasoline meant that Lippisch’s team was forced to seek other available resources, such as different forms of coal. This led to the creation of the slightly modified project named P 13. In contrast to the P 12, the cockpit was relocated from the fuselage into a large fin. This design provided better stability but also increased the aircraft’s aerodynamic properties. The overall designs of the P 12 and P 13 would change several times and were never fully finalized.
The P 12 and 13 small-scale models, in both configurations, were successfully tested at Spitzerberg Airfield near Vienna in May 1944. The project even received a green light from the Ministry of Armaments. In the early stages of the project, there were some concerns that the radical new design would require extensive retraining of pilots. However, the wind tunnel test showed that the design was aerodynamically feasible and that the aircraft controls had no major issues. Based on these tests, work on an experimental aircraft was ordered to begin as soon as possible.
A proposed P 12 aircraft. Its designs changed greatly over time, before being finally discarded in favor of the letter P 13. Source: The Delta Wing History and Development
The DM-1 Life Saver
While working on the P 12 and P 13, Lippish was approached with a request from a group of students from Darmstadt and Munich universities. They asked Lippisch to be somehow involved in the P 12 and 13 projects. Lippisch agreed to this and dispatched one of his assistants under the excuse that for his own project, a wooden glider was to be built and tested. The previously mentioned student’s and Lippisch’s assistant moved to a small warehouse in Prier and began working on the Darmstadt 33 (D 33) project. The name would be changed to DM 1 which stands for Darmstadt and Munich.
At this point of the war, all available manpower was recruited to serve the German war effort. For young people, this often meant mobilization into the Army. One way to avoid this was to be involved in some miracle project that offered the Army a potentially war-winning weapon. It is from this, that numerous aircraft designs with futuristic, and in most cases unrealistic, features were proposed. Many young engineers would go on to avoid military service by proposing projects that on paper offered extraordinary performance in combat.
The students and Lippisch managed to nearly complete their DM1 test glider when the war ended. Source: airandspace.si.edu
While it was under construction, preparations were made to prepare for its first test flight. As it was a glider it needed a towing aircraft that was to take it to the sky. A Sibel Si 204 twin-engine aircraft was chosen for the job. However, this was not to be done like any other glider, being towed behind the larger aircraft. Instead, the DM-1 was to be placed above the Si 201 in a frame, in a similar combination as the Mistel project. The estimated theoretical speeds that were to be reached were 560 km/h (350 mph).
Allegedly, there were four different proposals for the DM’s that were to be fully operational. The DM 2 version was estimated to be able to reach a speed of 800-1,200 km/h (500 – 745 mph). The DM 3’s theoretical maximum speed was to be 2,000 km/h (1,240 mph) while the fate of the DM 4 is unknown. Here it is important to note that these figures were purely theoretical, as there were no supersonic testing facilities to trial such a design. It is unclear in the sources if these additional DM projects even existed, even if in only written form. We must remember that the whole DM 1 glider idea was made to help the students avoid military conscription and that Lippisch himself never saw the DM 1 as any vital part of the P 13.
In any case, the glider was almost completed by the time the war ended and was later captured by the Western Allies. Under the US Army’s supervision, the glider was fully completed and sent to America for future evaluation. It would then be given to the Smithsonian Institution.
A DM 1 test glider being under construction. Source: hushkit.netThe Siebel Si 204 was to be used as a carrier for the DM 1 glider for the expected first-flight tests. Due to the end of the war, this was never achieved. Source: www.silverhawkauthor.com
Work on the P 13
As the work on the P 13 went on, the name was slightly changed. This was necessary as different variations of the P 13 were proposed. The original P 13 received the prefix ‘a’ while the later project’s designation continued alphabetically for example P 13b. After a brief period of examination of the best options, the P 12 project was discarded in favor of P 13. The decision was based on the fuel that the aircraft should use. What followed was a period of testing and evaluation of the most suitable forms of coal that could be used as fuel. Initial laboratory test runs were made using solid brown Bohemian coal in combination with oxygen to increase the burn rate. The fuel coal was tube-shaped, with an estimated weight of 1 kg, and encased in a mesh container through which the granulated coal could be ejected. The testing showed serious problems with this concept. While a fuel tube could provide a thrust that on average lasted 4 to 5 minutes, its output was totally unpredictable. During the testing, it was noted that due to the mineral inconsistency of the coal fuel, it was impossible to achieve even burning. Additionally, larger pieces of the coal fuel would be torn off and ejected into the jet stream. The final results of these tests are unknown but seem to have led nowhere, with the concept being abandoned. Given that Germany in the last few months of the war was in complete chaos, not much could be done regarding the Lippish projects including the P 13a.
As more alterations to the original design were proposed its name was charged to P 13a. Here is a drawing of a P 13b that was briefly considered but quickly discarded. Source: The Delta Wing History and Development
In May 1945, Lippish and his team had to flee toward the West to avoid being captured by the advancing Soviets. They went to Strobl in Western Austria, where they encountered the Western Allies. Lippisch was later transported to Paris in late May 1945 to be questioned about his delta wing designs. He was then moved to England, and then to America in 1946. The following year, American engineers tested the DM 1 glider at the wind tunnel facility of the Langley Field Aeronautical Laboratory. The test seems promising and it was suggested to begin preparation for a real flight. A redesign of the large rudder was requested. It was to be replaced with a much smaller one, where the cockpit would be separated from the fin and placed in the fuselage. Ironically Lippish was not mentioned in this report, as technically speaking he was not involved in the DM 1 project. Nevertheless, he was invited for further testing and evaluation of this glider. If this glider and the Lippish work had any real impact on the US designs is not quite clear.
Despite no aircraft being ever completed, one full-size replica of this unusual aircraft was built after the war. It was built by Holger Bull who is known for building other such aircraft. The replica can now be seen at the American Military Aviation Museum located in Virginia Beach.
An interesting full-size replica of the P 13 located at the American Military Aviation Museum. Source: Wiki
Technical characteristics
DM 1
The DM 1 glider was built using wooden materials. Given that it was constructed by a group of young students, its overall design was quite simple. It did not have a traditional fuselage, instead, its base consisted of a delta wing. On top, a large fin was placed. The cockpit was positioned in front of the aircraft within the large vertical stabilizer. To provide a better view of the lower parts of the nose, it was glazed. The landing gear consisted of three small landing wheels which retracted up into the wing fuselage. Given that it was to be used as a test glider, no operational engine was ever to be used on it.
The DM 1 side view. In contrast to the later P 13a design, the pilot’s cockpit position was placed above the wings. This was necessary as the engine was to be added. Source: airandspace.si.eduA DM 1 was captured by the Allies after the war. Its unique shape is quite evident in this photograph. Source: WikiA good example of DM 1 (to the right) and P 13a models that showed the difference between these two. The P 13a could be easily distinguished by its engine intake and the different position of the pilot cockpit. Source: Wiki
A good example of DM 1 (to the right) and P 13a models that showed the difference between these two. The P 13a could be easily distinguished by its engine intake and the different position of the pilot cockpit. Source: Wiki https://imgur.com/a/QW7XuO5
P 13a
The P 13 is visually similar but with some differences. The most obvious was the use of a ramjet. This means that the front, with its glazed nose, was replaced with an engine intake. Here, it is important to note, that much of the P 13a’s design is generally unknown, and much of the available information is sometimes wrongly portrayed in the sources. The P 13a never reached the prototype stage where an aircraft was fully completed. Even as the war ended, much of the aircraft’s design was still theoretical. Thus all the mentioned information and photographs may not fully represent how the P 13 may have looked or its precise characteristics, should it have been finished and built.
The exact ram engine type was never specified. It was positioned in the central fuselage with the air intake to the front and the exhaust to the back. As the main fuel, it was chosen to use small pieces of brown coal which were carried inside a cylindrical wire mesh container. The total fuel load was to be around 800 kg (1,760 lbs). Combustion was to be initiated by using small quintiles of liquid fuel or gas flames. The overall engine design was changed several times during the work on the P 13 without any real solution to the issues of output consistency. Given that the ramjets could not work without an air thrust, an auxiliary engine had to be used during take-off, though a more practical use would be to tow the P 13 until it could start its engine. A rocket takeoff ran the risk of the engine failing to ignite, leaving the pilot little time to search for a landing spot for his unpowered aircraft.
An illustration of the proposed P 13a engine interior. The use of coal as fuel may seem like a cheap alternative but given that this kind of technology was never employed may be an indication of its effectiveness. Source: theaviationgeekclub.com
The wing construction was to be quite robust and provided with deflectors that would prevent any potential damage to the rudders. The wing design also incorporated a sharp metal plate similar to those used for cutting enemy balloons cables. These proposed properties of the wings are another indicator that the P 13 was to be used as an aircraft rammer. Another plausible reason for this design was the fact that given it had no landing gear the aircraft design had to be robust enough as not to be torn apart during landing. The wings were swept back at an angle of 60 degrees. The precise construction method of the wings (and the whole P 13 a on that matter) are not much specified in the sources. Given the scarcity of resources in late 1944 it is likely that it would use a combination of metal and wood.
A drawing of the P 13a interior. Its overall construction was to be more or less standard in nature. This could not be said for the aircraft’s overall shape design. Source: D. Sharp Luftwaffe Secret Jets of the Third Reich
The fin had to be enlarged to provide good flight command characteristics. In addition, given that the position of the cockpit was in the fin, it had to be large. The fin was more or less a direct copy of one of the wings. So it is assumed that it too would share the overall design. The fin was connected to the aircraft by using four fittings.
The cockpit design was to be simple and cheap to build. The pilot was to have plenty of room inside the large fin. The cockpit was provided with a large glazed canopy that provided a good view of the front and sides. The seat and the instrument panel were bolted to the cockpit floor and walls. These could be easily detached for repairs. The instrument panel was to include an artificial horizon indicator, altimeter, compass, and radio equipment, Given that it was to operate at a high altitude oxygen tanks were to be provided too. Despite being intended to fly at high altitudes the cockpit was not to be pressurized. Another unusual fact was that initially the P 13 was to have a crew of two, but this was quickly discarded.
A possible example of how the inside of the pilot cockpit may have looked. Source: D. Sharp Luftwaffe Secret Jets of the Third Reich
Here it is important to note that the version of the P 13 with the large fin is often portrayed as the final version of this aircraft. However, Lippisch never fully decided whether he should go for this version or the second that used a smaller fin with the pilot cockpit placed above the engine intake. Depending on the proposed version they are drastically different from each other. Lippisch, for unknown reasons, presented the British intelligence officer with the version that used the smaller fin and the American with the second version.
During its development phase, many different alterations of the P 13 were proposed. Isource: D. Sharp Luftwaffe Secret Jets of the Third Reich
Landing operations were a bit unusual. To save weight no standard landing gear was to be used. Instead, Lippisch reused the Me 163 landing procedure. As the P 13 was immobile on its own, a small dolly would be used to move the aircraft. Once sufficient height was reached the dolly was to be jettisoned. In theory, this was an easy process, but in practice, this operation offered a good chance of failure and was much less safe than conventional landing gear. Sometimes the dolly either failed to eject or it bounced off the ground hitting the Me 163 in the process, with often fatal consequences.
The Me 163 which did not have traditional landing gear, had to be prior to the flight, transported to the airfield before launching into the sky. Source: warbirdphotographs.com
The aircraft was to land with the nose raised up from the ground. This limited the pilot’s view of the ground. In addition due to its small size and in order to save weight, nontraditional landing gear was provided, instead, it carried a landing blade skid. To help absorb the landing impact, additional torsion springs were to be used. This bar had to be activated prior to the landing, it would emerge from beneath the aircraft fuselage, with the rotation point located at the front. Once released it was to guide the aircraft toward the ground. After that, the torsion springs were to soften the landing. This whole contraption seems like a disaster just waiting to happen and it’s questionable how practical it would be.
A drawing that showed how the P 13a was to land using a guiding landing blade skid. Source: D. Sharp Luftwaffe Secret Jets of the Third Reich
One interesting feature of the P 13 was that it could be easily disassembled into smaller parts which would enable effortless transport. Another reason was that due to the engine’s position in order to make some repairs or replacement of the engine, the remaining parts of the wing and the large fin had to be removed.
Was it an aircraft rammer?
The precise purpose of the P 13a is not quite clear, even to this day. Despite being briefly considered for mass production, no official offensive armament is mentioned in the sources. So how would the P 13a engage the enemy? A possible solution was that it would be used as a ram aircraft that was supposed to hit enemy aircraft damaging them in the process. In an after-the-war interrogation by British officers, Lippisch was asked if the P 13 was to be used as an aerial ram aircraft. Lippisch responded the following “
“.. The possibilities of using the P.13 as a ramming aircraft had been considered but Dr Lippisch did not think that athodyd propulsion was very suitable for this purpose owing to the risk of pieces of the rammed aircraft entering the intake. This would be avoided with a rocket-propelled rammer…”
This statement contradicts the building description issued by the LFW issued in late 1944. In it was stated the following about this potential use. “…Due to tactical considerations, among other things, the speed difference of fighters and bombers, preferably when attacking from behind, though the thought was given to the installation of brakes .. and although ample room for weaponry is present, the task of ram fighter has been taken into account – so that the ramming attack will not lead to the loss of the aircraft, thanks to its shape and static structure.”
This meant that this concept may have been considered by Lippisch at some point of the project’s development. The P 13 overall shape resembles closely to aircraft that was intentionally designed for this role. That said, it does not necessarily mean that the P 13 was to ram enemy aircraft. The use of such tactics was considered but their use was discarded, as it was seen as a futile and flawed concept. The project itself never got far enough to have an armament decided for it.
The precise method of how to engage the enemy aircraft is not clear as the P13a was not provided with any armament. It is sometimes referred to in the sources as it was to be used as a ram aircraft. Source: theaviationgeekclub.com
Conclusion
The Lippisch P 13 is an unusual aircraft project in nearly all aspects. Starting from its shape, which proved, at least during wind tunnel tests, that the concept was feasible. On the other hand, its engine seems to have simply been abandoned after discouraging test results. It is unlikely that such a combination would have worked to the extent that the P 13 designer hoped it would. During the testing, they could not find a proper solution to providing a constant thrust with sufficient force to reach a speed that was expected of it. So the whole concept was likely to be doomed from the start.
The DM 1 however, while it was never seriously worked on by Lippisch himself, managed to save a group of young students who used the project to avoid being sent into combat.
DM-1 Specifications
Wingspans
5.92 m / 19 ft 5 in
Length
6.6 m / 21 ft 7 in
Height
3.18 m / 10 ft 5 in
Wing Area
20 m² / 215 ft²
Engine
None
Empty Weight
300 kg / 655 lbs
Maximum Takeoff Weight
460 kg / 1,015 lbs
Maximum Speed
560 km/h / 350 mph (gliding)
Landing speed
72 km/h / 45 mph
Release altitude
8,000 m (26,240 ft)
Crew
1 pilot
Armament
None
Theoretical Estimated Lippisch P 13 Specifications
Wingspans
5.92 m / 19 ft 5 in
Length
6.7 m / 21 ft 11 in
Height
3.18 m / 10 ft 5 in
Wing Area
20 m² / 215 ft²
Engine
Unspecified ramjet
Maximum Takeoff Weight
2,300 kg / 5,070 lbs
Maximum Speed
1,650 km/h / 1,025 mph
Flight endurance
45 minutes
Fuel load
800 kg / 1,760 lb
Crew
1 pilot
Armament
None mentioned
Illustrations
The Lippisch DM-1, unnecessary to the overall project, it none the less allowed a group of students to escape military service.
A possible silhouette of the P13.
Credits
Article written by Marko P.
Edited by Henry H.
Ported by Marko P.
Illustrated By Medicman11
Source:
A. Lippisch (1981) The Delta Wing History and Development, Iowa State University Press
D. Nesić (2008) Naoružanje Drugog Svetsko Rata-Nemačka. Beograd.
D. Monday (2006) The Hamlyn Concise Guide To Axis Aircraft OF World War II, Bounty Books.
J. R. Smith and A. L. Kay (1972) German Aircraft of the WW2, Putham
B. Rose (2010) Secret Projects Flying Wings and Tailless Aircraft, Midland
D. Sharp (2015) Luftwaffe Secret Jets of the Third Reich, Mortons
Kingdom of Hungary (1939)
Fighter Aircraft – One prototype
In their search for a new fighter, the Magyar Királyi Honvéd Légierő MKHL (English: Royal Hungarian Home Defence Air Force), approached the Germans for help. Initially, a deal was made with the German Heinkel company for the delivery of new He 112 fighters and a production license. However, nothing came of this deal, which led to the Hungarians attempting to develop their own fighter, partially based on the He 112.
In the late 1930s, the Hungarian Air Force was slowly in the process of rebuilding its combat strength by the acquisition of new aircraft. For a modern air force, they needed better fighter designs, which they were then seriously lacking. Luckily for them, they began to improve their relations with Germany, so it was possible to acquire new equipment from them. In June 1938, a Hungarian delegation was sent to the Heinkel company, and the pilots that accompanied this delegation had a chance to fly the He 112 fighter. This aircraft was Heinkel’s response to the Reichsluftfahrtministerium’s (English: German Ministry of Aviation) request for a new fighter. While generally a good design, it ultimately lost to Messerschmitt Bf 109. While the He 112 project was canceled by the RLM, to compensate for the huge investment in resources and time to it, Heinkel was permitted to export this aircraft to foreign buyers. Several countries such as Austria, Japan, Romania, and Finland showed interest, but only a few actually managed to procure this aircraft, and even then, only in limited numbers.
He 112 the unsuccessful competitor of the Bf 109. Source: www.luftwaffephotos.com
The Hungarians were impressed with the He 112 and placed an order for 36 such aircraft. For a number of logistical and political reasons, the decision to sell these aircraft to Hungary was delayed. A single He 112 was given to Hungary in February for evaluation but was lost on its first flight. Realizing that the Germans would not deliver the promised aircraft, the Hungarians instead decided to ask for a license. This was granted and Heinkel also delivered two more He 112 B-1s. When the license arrived in Hungary in May 1939, a production order for the 12 first aircraft was given to Weiss Manfréd aircraft manufacturer.
The first He 112 to reach Hungary, it was lost in an accident during its maiden test flight. Source: D. Bernard Heinkel He 112 in Action
A New Fighter
Despite the best Hungarian attempts to put the He 112 in production, this was prevented by the war between Poland and Germany. At the start of the Second World War, RLM officially prohibited the export of any German aircraft engines and equipment. This meant that the vital Jumo 210 and DB 601 engines would not be available. Based on this fact, all work on the Hungarian He 112 had to be canceled.
The Hungarian Air Force only operated a few He 112, which saw limited service before being reused as training aircraft. Source: www.destinationsjourney.com
As the Hungarians had the license for the He 112, some parts could still be domestically produced. In essence, this offered the Hungarians the chance to develop a new fighter, based on the He 112 blueprints. Not wanting to waste this opportunity, the Hungarian Ministry of War Affairs issued a directive to commence developing a new domestic fighter by reusing some components from the He 112. The whole project was undertaken by WM’s own chief designer Bela Samu, who began development in early 1939. To speed up development, the He 112 wing design was copied, but given the comparatively underdeveloped Hungarian aircraft industry, the wing was to be built of wooden materials instead of metal, as it was on the He 112. Other differences included using an oval-section fuselage, different armament, a new engine, and a cockpit redesign.
The first prototype was completed quickly by the end of 1939. In its prototype stage, the aircraft was painted in a light gray livery, earning it the nickname Ezüst Nyíl (English: Silver arrow) from the personnel that worked on it. Once it was issued to the Air Force for testing, it received the standard Hungarian camouflage scheme, and the designation V/501 was also allocated to it. The maiden test flight was undertaken close to Budapest on the 23rd of February 1940. The flight proved successful and a maximum speed of 530 km/h (330 mph) at a height of 5 km (16.400 ft) was achieved. Some issues were detected, the most problematic proved to be the strong vibration caused by the exhaust system. Despite this, the project development pressed on.
The WM 23, possibly at an early stage of development. It was powered by a 1,030 hp WM K-14B engine which gave it comparable power to the He 112. Source: www.destinationsjourney.com
Short Service Life
Despite the time and effort put into the project, it all went for nothing as the prototype was lost in an accident in February, or April, depending on the source, 1942. During a test flight at high speeds, one of the ailerons simply broke off. The pilot lost control of the aircraft and had to bail out. The uncontrolled plane hit the ground and was utterly destroyed, and with it, the whole project was canceled.
Beyond this major setback, another reason why this project was canceled was the start of the license production of the German Bf 109G fighter. It was much easier, and faster, to commence production of this aircraft, thanks to German technical support, than to completely develop new tooling and equipment for the WM 23.
Technical Characteristics
The WM 23 was a mixed-construction single-engine fighter heavily inspired by the German He 112. Given its somewhat obscure nature, not much is mentioned in the sources about its overall construction. Given the urgency of the project, instead of the monocoque fuselage, the Hungarian engineers decided to use a simpler oval-section fuselage which consisted of welded steel tubes and then covered with plywood. The wings, as mentioned, were taken from the He 112, but had one huge difference, being made of wood, including its control surfaces.
The landing gear was another part more or less taken directly from the He 112. They consisted of two larger landing wheels that retracted into the wings, and one semi-retractable tail wheel. But based on the photographic evidence, their overall design changed during the prototype’s development. On the prototype, possibly at an early stage, a V-shaped front landing gear strut was used. This was later replaced by a large single-leg landing gear. The cockpit was equipped with a sliding canopy that slid to the rear.
The WM 23 was powered by a 1,030 hp WM K-14B (sometimes marked as 14/B) engine. This engine was developed based on the license of the French Gnome and Rhone 14K engine, a fourteen-cylinder radial engine equipped with a single-stage, single-speed supercharger. As mentioned, during the fifth test maximum achieved speed was 530 km/h (330 mph).
While the prototype was never fitted with an offensive armament, the Hungarians had plans for a potential armament In the wing, two 8 mm (0.33 in) machine guns were to be installed. In addition, two 12.7 mm (0.5 in) heavy machine guns were to be added atop the engine compartment. Lastly it was to have a payload of two 20 kg bombs (44 lbs).
There are very few surviving photographs of the WM 23. While showing promising performance, the destruction of the only prototype and the commencement of the Bf 109G’s production in Hungary ultimately lead to the cancelation of this project. Source: D. Bernard Heinkel He 112 in Action
Conclusion
The WM 23 was an interesting Hungarian attempt to domestically develop and build a fighter aircraft that was greatly influenced by the He 112. It showed to be a promising design, with the prospect of entering serial production. However, the loss of the single prototype put an end to this project. By 1942, the Hungarians simply did not have the time to start over again with the WM 23, so they abandoned it in favor of the license production of the German Bf 109G.
WM 23 prototype Specifications
Wingspans
31 ft 5 in / 9.6 m
Length
29 ft 10 in / 9.1 m
Height
10 ft 9 in / 3.3 m
Wing Area
199 ft² / 18.5 m²
Engine
One 1,030 hp strong WM K-14B
Empty Weight
4,850 lbs / 2,200 kg
Maximum Take-off Weight
5,733 lbs / 2,600 kg
Maximum Speed
330 mph / 530 km/h
Crew
1 pilot
Proposed Armament
Two 12.7 mm (0.5 in) heavy machine guns and two machine guns 8 mm (0.33 in) machine guns plus a bomb load of 20 kg (44 lbs)
Credits
Article written by Marko P.
Edited by Henry H.
Ported by Marko P.
Illustrated By Carpaticus
Illustrations
The WM-23’s factory test colorsWM-23 with Hungarian Airforce livery
Source:
D. Monday (2006) The Hamlyn Concise Guide To Axis Aircraft OF World War II, Bounty Books
D. Bernard (1996) Heinkel He 112 in Action, Signal Publication
G. Punka, Hungarian Air Force, 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
J. R. Smith and A. L. Kay (1990) German Aircraft of the Second World War, Putnam
Nazi Germany (1940)
Light Transport and Trainer – Number built: 1,175
While often seen as less exciting than their combat counterparts, transport and auxiliary aircraft provided vital services in moving cargo, and training new pilots. Light transports which could combine both duties were thus extremely desirable during the war as theaters stretched across continents and pilot attrition was high. Luckily for the Luftwaffe, the Siebel company provided them with a simple but effective aircraft that could easily fulfill both roles. This was the Si 204, which saw wide-scale use both during, and after, the conflict.
The Si 204. Source: www.airwar.ru/
Siebel company history
The story of Siebel began back in 1936 when Hans Klemm opened a new aircraft factory the, Flugzeugbau Halle GmbH. This company would go on to produce license-built aircraft, including the Focke-Wulf Fw 44, and Heinkel He 46. Between 1936 and 1937, a new project led by Hans Klemm was initiated. This was a light twin-engined transport aircraft designated as Fh 104. While the work was going on, Klemm decided to hand over the factory to well-known aircraft enthusiast Fritz W. Siebel. The same year the name was changed to Siebel Flugzeugwerke Halle GmbH. Under new management, the work on the renamed Siebel Fh 104 continued. The Siebel Fh 104 would prove to be a solid design and was pressed into Luftwaffe service as a communication and liaison aircraft. In 1942 the production of this aircraft was terminated, by which time only some 46 were built. The Siebel factory would survive the war and even produce a few new aircraft designs. It would continue to exist up to 1968 when it was merged with Messerschmitt-Bolkow GmbH.
The first aircraft to come out of the o Siebel Flugzeugwerke production was the Siebel Fh 104 Source: hwww.armedconflicts.com
The Siebel 204
Following the success of the Fh 104, Siebel received a request from the Luftwaffe officials in 1939 to design and build a new twin-engine, 8-passenger transport aircraft. So Siebel and his team of engineers began working on such a design. While they may have used the experience gained while working on the Fh 104, their next project was a completely new design. The first prototype Si 204 V1 (D-AEFR) was completed in early 1940, and was flight tested on the 25th of May the same year. Sources disagree about the year when the maiden flight was made. For example, D. Nešić and M. Fratzke mentioned that it happened in 1941 while M. Griel placed it in 1940. The test flight proceeded without any major issues, so the development of this aircraft carried on. In October 1940 the Si 204 V2 (D-IMCH) was flight tested. Both of these would serve as bases for the pre-production A-0 series which were to be operated by the German Lufthansa airline. The first prototype was scrapped in 1942 while the second remained in use up to early 1944 when it was lost in an accident.
Following its successful testing, the first production version known as Si 204A was built. It was powered by two 360 hp, or 465 hp depending on the source, Argus As 410 engines. The Si 204A-0 and A-1 were put into production in 1941, the precise numbers are not clear but were likely limited. As the war dragged on these were mainly used for crew training, a role to which they proved well suited.
The Luftwaffe was generally satisfied with the Si 204A’s performance as a trainer but requested that a new version of it be built. This version was dedicated to various crew training tasks including; radio navigation, instrument flying, bombing, and communication. Other requests were made regarding its front canopy design and stronger power units. For this reason, the engines were replaced with two 600-hp Argus As 411 12-cylinder engines. Additionally, the original stepped canopy was replaced with a fully glazed canopy.
The new version was to be designated Si 204D. The fate of the skipped B and C versions is unclear, but these were likely only paper projects. The Si 204V3 and V4 served as bases for the Si 204D aircraft. Both were flight tested in early 1941, withhe V3 being lost in an accident during mid-1942 while the fate of the V4 is not known.
Technical characteristics
The Si 204 was designed as a low-wing, twin-engine, all-metal transport, and training aircraft. Its fuselage was made of round-shaped formers each connected with a series of metal bars. These were covered with sheet metal plating. On the fuselage sides, there were four rectangular windows.
The wings and tail units were also of an all-metal construction. The wings were built using only a single spar. The dihedral tailplane was divided into two fins and rudders, which were located on their tips.
In the last months of the war, due to shortages of resources, Siebel attempted to replace some metal components using wooden materials. The end of the war prevented any of these wooden components from ever being used.
The pilot and his assistant were positioned in the front. As many German bombers had a fully glazed canopy, to help with the training and adaptation of new pilots, the Si 204 was also equipped with such a designed canopy. It largely resembled the one used on the He 111. Thanks to it the pilot had an excellent view during the flight.
As mentioned earlier, Si 204D was powered by two 600 hp Argus As 411 12-cylinder engines, these used two variable pitch blade propellers. The maximum speed achieved with these engines was around 364 km/h. With a fuel load of 1.090 liters, the maximum operational range was around 1.800 km.
The landing gear was more or less a standard design. It consisted of three wheels. The landing gear retracted back into the engine nacelles. These were not fully enclosed and part of the wheels was exposed. The tail wheel was not retractable.
While initially designed as a passenger transport aircraft, the Si 204 would be primarily used for crew training. For this reason, its interior compartment could be equipped with different training equipment depending on the need. Including radio, radar, or navigation equipment.
The Siebel 204D side view. Its overall design is quite similar to the German he 111 bombers. Source: www.airwar.ruSiebel pilot cockpit interior. The pilot and his assistant had an excellent view of the surrounding thank to the large glazed cockpit. Source: www.airwar.ruThe Siebel 204D had standard landing gear. The two front wheels retracted back into the engine nacelles. These were not fully enclosed and part of the wheels was exposed. Source: www.airwar.ru
Production
Despite being Siebel’s own design, the factory itself lacked production capabilities as it was already heavily involved in the manufacturing of other designs including the Ju 88. The actual production was redistributed to two occupied foreign factories. The first were the SNCAC factories located in Fourchambault and Bourges in France, which came under German control after the successful end of the Western Campaign in 1940. The second production center was located at the Czechoslovakian Aero factory, which was also occupied by the Germans even before the war started. Other companies like BMM and Walter were also involved in the production of this aircraft.
The production numbers were initially low, for example, the SNCAC only managed to build five aircraft per month during 1942. From 1942 to 1944 this company produced some 150 Si 204D aircraft. Czechoslovakian production capabilities proved to be better, managing to manufacture some 1007 such aircraft by the end of the war. The total production of all versions during the war is around 1.175 aircraft according to H. A. Skaarup. This number, as is the case with many German production numbers, may be different in other sources.
Service
As mentioned earlier the Si 204 was mainly used for crew training for various roles, transportation, and glider towing. While there is quite limited information on their precise service life, it appears to be quite a successful design and was praised by the Luftwaffe pilots. By the end of the war, some were even equipped with various radar equipment including FuG 217R and FuG 218V2R tail warning radars to train night fighter pilots. Interestingly the Si 204 was employed for the training of further Me 262 pilots.
It is often mentioned that the Si 204 was the last Luftwaffe aircraft to be shot down. Near Rodach in Bavaria, just a day before the Germans capitulated to the Allies. That kill is accredited to Lieutenant K. L. Smith, a pilot of a P-38 Lightning from the 474th Fighter Group. How valid this claim is difficult to know precisely due to the general chaotic state in Germany at that time.
During its service life, the Si 204 proved to be an effective aircraft, completely suited for its designated role. Source:www.airwar.ru
Combat adaptation attempts
For fighting against Partisan movements in occupied Europe, older or modified aircraft were often reused, preserving the more modern aircraft for the front line use. The Si 204 was seen as tempting for such a modification, so the Siebel engineers tried to develop a fully armed combat version of this aircraft. To fulfill this role some extensive modifications were needed.
Inside its front fuselage, two 13 mm MG 131 heavy machine guns were placed. Each was supplied with 500 rounds of ammunition, stored in a metal ammunition bin. These were to be operated by the pilot. For this reason, he was provided with a Revi 16A-type gun sight. For protection against enemy aircraft, on top of the fuselage, a fully glazed turret armed with one 13 mm MG 131 was added. The turret movement was electrically controlled. Elevation was -10 to +80 while it could achieve a full 360 rotation.
The interior of the Si 204 received a bombing bay that could carry 12 70 kg bombs. External bomb racks with a capacity ranging from 50 to 500 kg were added. The pilot seat received armor plates for his protection from enemy fire on the Si 204E. Due to its relatively slow speed, using this aircraft against a well equipped enemy was dangerous, so it was to be restricted to night bombing action only.
In 1944 two prototypes were completed and tested. Besides these two, the number of Si 204E’s built is unknown. Given its experimental nature, possibly only a few prototypes were ever completed. Allegedly these saw limited action fighting the Belarusian Partisans. The extent to which they were used in this role if used at all, remains unknown.
The Siebel 204E could be easily distinguished by its glazed turret, located on the fuselage top. This version is somewhat obscure as it is not known how many were built and if they ever saw action in combat. Source: www.silverhawkauthor.com
Carrier proposal
With the Allies slowly getting the upper hand in the air over Europe, the Luftwaffe became ever more desperate to find a solution to this problem. Mass production of cheap fighters was seen as a possible solution. One such project was proposed by Professor Alexander Lippisch, best known for designing a series of glider fly-wing designs. He was also involved in designing various bizarre aircraft projects, including the unusual P 13a aircraft.
A drawing of Professor Alexander Lippisch P 13a fighter. Source: D. Sharp Luftwaffe Secret Jets of the Third Reich
While working on the P 13, Lippish was approached with a request from a group of students from Darmstadt and Munich universities who wanted to avoid conscription to join his work. Lippisch agreed to this and dispatched one of his assistants under the excuse that for his own project, a wooden glider was to be built and tested. They together managed to build an experimental DM-1 glider.. However, this aircraft was not to be towed like any other glider. Instead, the DM-1 was to be placed above the Si 201 on brackets and carried. However, nothing came of this project, and no such attempt at deploying the glider was made as the war ended.
Professor Alexander Lippisch’s work involved designing unusual and unorthodox aircraft designs including the Li DM 1. Source: Professor Alexander Lippisch’s work involved designing unusual and unorthodox aircraft designs including the Li DM 1. Source: www.fiddlersgreen.net
After the war
When the war ended, the Si 204 would see more service in the hands of many other nations. The advancing Allies managed to capture a number of fully operational aircraft. These were immediately put to use either as transport, liaison, and evaluation purposes. At least one Si 204D was extensively used by the British pilot Captain Eric Brown, who was the chief test pilot of the Royal Aircraft Establishment at Farnborough. He was involved in a British project tasked with taking over German war research installations and interrogating technical personnel after the war.
He was generally impressed with the Si 204D’s overall performance, performing many flights on it. He later wrote about its performance. “The Si 204D was really a viceless airplane to handle, with inherently good stability about all three axes and good harmony of control. It was very well equipped for its tasks, and the later model I flew had an autopilot fitted. Like all German aircraft of that era, it was a mass of electrics, with extensive circuit breaker panels, and all very reliable. However, the one thing the Germans never got right was wheel brakes, and the Sievel was no exception..”
A group of six or more Si 204 was captured by the Allies. Source: www.asisbiz.com
The Siebels that were moved to Farnborough were extensively used during 1945 for various roles, like communication, providing navigational guidance, and transporting pilots to various captured Luftwaffe airfields. The last operational flight of the Si 204D at this base was recorded at the start of 1946.
After the war, the Si 204 saw the most common use in French and Czechoslovakia, which actually continued to produce this aircraft. In French service, these were known t as NC 700, powered with As 411 engines, NC 701 ‘Martinet’, powered by two Renault 12S engines, and NC 702, a modified version of the Si 204A. In total the French constructed over 300 aircraft of this type. Some would see service in French Asian and African colonies. The last operational flight was carried out in 1964. Two NC 702’s would be given to Maroko in 1960, but their use and fate is unknown.
After the war, the French sold 7 NC 701 to Poland. They were used mainly for mapping photography. These were operated until the mid-1950s’ before being put out of service.
By mid-1960 some 5 French-built Siebels were given to the Swedish National Geographic Institut. These were mainly used for taking meteorological photographs.
The second country that produced the Si 204 was Czechoslovakia. They were built in two versions, the C-3 for the army and C-103 for civilian use. Both were mainly operated in their original transport roles. From 1945 to 1950 some 179 would be built.
The Soviets also managed to capture an unknown number of operational Si 204. These were briefly pressed into service before being replaced by domestic-built designs.
Switzerland also operated at least one Si 204D. This aircraft and its crew escaped from Germany on the 7th of May 1945 and landed at Belp near Bern. The Si 204D would remain in Switz use under the B-3 designation.
Soviets operated an unknown number of Si 204. Their use was brief as it was replaced with new Soviet-built designs. Source: www.armedconflicts.comDuring late 1945 and early 1946 the Si 204 were used by the Western Allies for transport and evaluation. Source: www.airwar.ru
Production Versions
Si 204 – Prototype series
Si 204A – Transport and training version built in small numbers
Si 204B and C – Unknown fate, but likely paper projects only
Si 204D – Model with a new glazed cockpit and powered with a stronger engine
204E – Experimental modification for combat operational use
Flying carrier – One Si 204 was to be modified as a carrier for the Doctor Alexander Lippisch experimental all-wing fighter, but was never fully implemented
Operators
Germany – Most produced planes were used by the Luftwaffe primarily used for crew training
Czechoslovakia – Produced some 179 additional aircraft for military and civilian use
France – Over 300 modified aircraft (with French engines) were produced in France and saw wide service up to 1964.
Soviet Union –Operated some captured Si 204
Poland – Brought 7 NC.701 from France after the war
Macoro – Operated two French NC 702
Sweden – Operated five French-built Siebels
Switzerland – Used at least one Si 204 under the designation B-3
American and Great Britain – Both briefly operated a number of captured Si 204 after the war
Surviving aircraft
Today there are a number of partially or wholly survived aircraft Si 204. For example, the French Aviation Museum in Paris had one Si 204A and another located in the Escadrille du Souvenir close to Paris. One Si 204 is located at Sweden Lygvapen Museum.
Conclusion
While Germany in the Second World is better known for designing and producing a series of combat aircraft, their auxiliary aircraft are often overlooked. The Si 204 was one such case, despite its successful design, it is rather poorly documented in the sources. Its design was a success which can be seen in its after-war use, most notably by the French up to the mid-1960.
Si 204 D Specifications
Wingspans
21.33 m / 70 ft
Length
12 m / 39 ft 3 in
Height
4.25 m / 14 ft
Wing Area
46 m² / 495 ft²
Engines
Two Argus As 411 engines
Empty Weight
1.500 kg / 3.300 lbs
Maximum Takeoff Weight
3950 kg / 8,710 lbs
Climb Rate to 1 km
In 3 minute 30 seconds
Maximum Speed
364 km/h / 226 mph
Cruising speed
340 km/h / 210 mph
Range
1,800 km / 1,120 miles
Maximum Service Ceiling
7,500 m / 24,600 ft
Crew
Pilot and his assistants plus eight-passenger
Armament
None
Illustrations
Si-204DSi-204E
Credits
Article written by Marko P.
Edited by Henry H. & Stan L.
Ported by Marko P.
Illustrated By Ed Jackson
Sources
D. Nešić (2008), Naoružanje Drugog Svetskog Rata Nemačka Beograd
H. A. Skaarup (2012) Axis Warplane Survivors
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
Captain E. ‘Winkle’ Brown (2010) Wings of the Luftwaffe, Hikoki Publication
M. Griehl (2012) X-Planes German Luftwaffe Prototypes 1930-1945, Frontline books
T. H. Hitchcock (1998) Jet Planes Of The Reich The Secret projects, Monogram Aviation Publication
Sweden (1941)
Italy (1932)
Empire of Japan (1937)
Independent State of Croatia (1943-1945)
Kingdom of Hungary (1938)
Nazi Germany 
