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A7He1 (He 112) in Japanese Service

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.

He 112 the unsuccessful competitor of the Bf 109. Source: www.luftwaffephotos.com

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.com
Another 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.
  • https://airpages.ru/eng/lw/he112_combat_use.shtml

 

ANT-1

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

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

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

History

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

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

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

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

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

Due to problems with the production of the new alloy, Tupolev was forced to postpone the development of his new aircraft until 1922. At that time the alloy was not yet available, so Tupovlev decided to go on with a 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.org
The cantilever wings received on each side one large wooden spar. Source: Wiki
The pilot cockpit received only a few basic instruments and a small windshield. Source:www.globalsecurity.org

Conclusion

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

ANT-1 Specifications

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

 

Gallery

 

 

Credits

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

Sources:

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

 

Westland Whirlwind

Great Britain (1939)

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: Wiki
Given 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.com
Close-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 Whirlwind
While 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
  • https://www.whirlwindfp.org/

 

He 112 in Hungarian Service

Hungarian Flag 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.

One of few He 112 in Hungarian service. Source: www.destinationsjourney.com

A brief He 112 history

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.

He 112 the unsuccessful competitor of the Bf 109. Source: www.luftwaffephotos.com

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.com
The V.303 during pilot training in 1940. Source: www.destinationsjourney.com
Despite 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.com
In 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

 

Lippisch P 13a

Nazi flag Nazi Germany 

Ramjet powered aircraft

None built

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.net
The 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.edu
A DM 1 was captured by the Allies after the war. Its unique shape is quite evident in this photograph. 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

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

 

 

Focke-Wulf Ta 152H

Nazi flag Nazi Germany (1945)

Fighter: Approximately 60 built

A Ta 152H undergoing compass calibration. (flugrevue)

Introduction:

Throughout the Second World War, the job of the interceptor would become ever more challenging. Their targets, mostly bombers and photo reconnaissance aircraft, would fly ever higher and faster thanks to new advancements in turbo and supercharging. With Germany under a state of permanent siege and surveillance by aircraft like the Boeing B-17 and De Havilland Mosquito, it was clear the Luftwaffe needed a specialized interceptor to effectively reach these high flying threats and the multitude of new fighters that were appearing in growing numbers. After several failed attempts to develop the Fw 190 into such an interceptor, Kurt Tank designed the Ta 152H. The short lived design incorporated all of the available developments in high altitude flight available to German aviation in an attempt to create the ultimate high altitude fighter.

High altitude threats and Interceptors

In the summer of 1941, the Mosquito was making its first reconnaissance sorties and becoming one of the gravest threats to German aerial defenses. Operating above 7km and capable of reaching speeds upwards of 560 km/h, the aircraft was almost untouchable after it had reached its destination. Once they had taken their photos, they turned for home and entered a shallow dive that allowed them to accelerate to speeds beyond those of pursuing fighters who were not already chasing them from a higher altitude. With such a small interception window, they were a chief concern to the Luftwaffe. Doubly so were the bomber variants of the aircraft, which raided targets all over North Western Europe.

The following year saw the entrance of the United States into the Second World War, their air force possessing some of the most capable high altitude aircraft at the time. Investments in engine turbocharging allowed them to field a number of bombers and fighters with exceptional high altitude performance. B-17’s were conducting regular operations above 7 km. At first, they undertook operations at significantly lower altitudes, never straying too far from their air bases in southern England, but it was becoming clear that they would soon pose a threat that the Luftwaffe was ill equipped to combat.

The De Havilland Mosquito was quickly recognized as a serious threat not long after its introduction. Photorecon versions, like this later Mk XVI here, could surveil Germany with little fear of interception. (wikimedia)

The only two fighters of consequence employed by the Luftwaffe, the Bf 109 and Fw 190, were effective low to medium altitude fighters. However, through 1942, both were operating with engine power restrictions, and supercharger related performance bottlenecks. While inferior alloys and lubricants were causing a variety of issues, that was less of a concern than the engines themselves not being designed for use at high altitudes. The Bf 109G’s DB 605A, with its variable single stage blower, provided a full throttle height of roughly 6.5 km, depending on the variant. The Fw 190’s BMW 801, with its significantly simpler, single stage, double speed supercharger, was even worse off. Its critical altitude was only roughly 6 km, leaving it, and the 109, distinctly lacking in power at the over 7.5km B-17’s often flew at. Above these altitudes, neither engine could maintain the manifold pressure needed for combat power, putting them at a distinct disadvantage in trying to catch the Mosquito, or fighting American high altitude fighters which were soon making forays into German airspace. As the USAAF began its strategic bombing campaign against Germany proper, there were deep concerns within the Luftwaffe about the battle they were soon to fight, and for which they were clearly technically unprepared for. Even more concerning was the fear that the RAF would soon be operating the Vickers Wellington V bomber, which was reportedly capable of operating at an almost untouchable altitude of 12 km. They never entered service, but were the impetus for the creation of a specialized high altitude fighter with the Höhenjäger program.

With these anxieties building, the RLM convened a conference on the development of high altitude fighters on May 20, 1942 at Messerschmitt’s plant in Augsburg. In addition to the high altitude British bomber, further concerns were spelled out over the recent study of the new Merlin 61 engine, which, with its two stage, two speed supercharger, promised to make the Spitfire and Mosquito even more challenging opponents at high altitude. Of particularly grave concern was that the German aviation industry could not simply follow the same development path as the Allies. The poor qualities of their available alloys and the inadequate supplies of high octane fuels meant that even, if they had a factory furnished with all the tools to manufacture an engine like the Merlin 61, they simply could not build or operate it with the materials at hand.

As such, they had to pursue less conventional means of improving performance. Messerchmitt proposed a redesign of a former naval fighter proposal for high altitude use. The Me 155 carrier based fighter design, with its very long wingspan, was proposed to be converted for high altitude use, the work being done mostly at the S.N.C.A.N plant in Paris. The design would later be taken up and heavily altered by Blohm & Voss, who went on to design the Bv 155, with turbochargers and GM-1 nitrous boosting. Neither design came to fruition. A secondary design, the Bf 109H, would involve stretching the wingspan of a Bf 109F, and later G, and installing the high altitude GM-1 engine boost system. Likewise, this design was not pursued. In the end, Messerschmitt would go on to design a mass production, high altitude variant of their standard Bf 109G with a pressurized cockpit and nitrous boosting. While it would prove fairly adequate for the time, it was held back by the need for GM-1, which was difficult to transport in large quantities without a pipeline.

Focke-Wulf would face an even greater challenge with their program. While their Fw 190 was proving to be among the best medium altitude fighters of the war, its short wingspan and outdated supercharger meant it would take a considerable effort to make a high altitude fighter out of it.

The Höhenflieger Fw 190

Focke-Wulf first pursued turbocharging to get their fighter to reach the adequate level of performance for the Höhenjäger project. Almost immediately, they ran into the issue that it was almost impossible to fit a suitable turbocharger into a Fw 190A, though an externally mounted, and almost completely unwieldy unit was suggested. The first serious effort came with the proposal for the Fw 190B fighter, or Höhenjäger 1, in August of 1942. The design would take the then in production Fw 190A-3, increase its wingspan from 10.5 to 12.4 meters (increasing its area from 18.3 to 20.3 m^2), and install a pressurized canopy. The engine was initially unmodified and nitrous boosting was not pursued, in the hope a suitable turbocharger would be developed. The prototype, Fw 190V-12, began testing, but was abandoned in favor of using older, pre-production Fw 190A-0 prototypes before moving on to pre-production. The Fw 190B-0 received the new BMW 801 D-2 and several other modifications going into the new A-5 fighter. It began testing in December of 1942, and despite some faults with the pressurized canopy, which were later corrected, the aircraft had considerably better high altitude handling than the original A model. All four of the A-0’s were converted, but the program showed little promise. Despite the effort, the improvements were not enough and the aircraft was still too slow at high altitude. It was clear that the aircraft needed a heavily modified, or entirely different engine, in order to attain the level of performance needed.

Perhaps the most promising development for the next generation of the Fw 190, the C series, hoped to install a much more powerful DB 603 engine. Harsh teething issues and limited supplies for the engine doomed the project. (grafiq)

In parallel with the B-project, the decision was made to re-engine the aircraft with either the Junkers Jumo 213, or Daimler Benz’s DB 603. Both promised better high altitude performance over the BMW 801 along with a considerable overall increase in engine output. The DB 603 project would proceed with the designation Fw 190C, and the Jumo 213, Fw 190D. The first Fw 190C prototype, V13, had a DB 603 installed, with an annular radiator at the nose of the aircraft and its supercharger intake mounted between its two oil coolers, these modifications presenting a longer, but more streamlined profile. Little drag was added to the airframe with the modifications initially, but they would be forced to mount the supercharger scoop externally. The aircraft first flew in March of 1942, and overheating, along with general teething issues would be noted. Two more prototypes were converted, V15 and 16, receiving the longer wing from the B-project and GM-1 equipment. Turbocharging was also proposed, but not pursued until much later on. The program continued through May at a decent pace and they were achieving high speeds, one aircraft reaching 696 km/h at 6,950 m, but overheating and engine failure remained serious issues. Similar problems were likewise being experienced with the Jumo 213. The results, however, prompted Focke-Wulf to expand the program with six more prototypes, V13,15,16, 19, 20, 21, 25, 26, and 27 carrying the DB 603, and V22 and 23 using the Jumo 213. Despite the focus on the DB 603, the company was prepared to switch to the Jumo 213, which they could obtain a much larger supply of.

The large, drag inducing turbocharger scoop earned this aircraft the moniker ‘kangaroo’. Aerodynamically unsound, it proved unsatisfactory for service. (wwiiforum)

The final design for the Fw 190C featured the DB 603A with its supercharger intake mounted on the port engine cowling, with various provisions for an armament of MG 131 machineguns, MG 151/20, and MK 108 autocannons. Its highest tested speed was an impressive 722 km/h at 9 km, without armament or armor plates. Production was strongly considered, and then canceled. The DB 603, in its fighter configuration, was still proving troublesome, and V13 was written off after an engine failure forced the pilot to crash land. The engine itself had a comparatively small production run compared to the Jumo 213, and was being shared with a number of twin engine bombers and night fighters. As the older, and massive Jumo 211 production lines were transitioning to the more powerful Jumo 213, it was by far the better choice for a new mass production fighter.

The Fw 190D or ‘Dora’ project continued, though its development path did not lead to a mass produced, high altitude fighter. Rather, it became a project to facilitate getting the Jumo 213 into a fighter as fast as possible, as it was one of the few German engines capable of competing with Western Allied models in most areas. The only mass produced variant, the D-9, is often mislabeled as a high altitude fighter, though its engine was designed for low to medium altitude use. A small number of high altitude models, with the appropriate engines, were produced, but were nothing compared to the D-9’s production run of well over a thousand aircraft by the end of the war.

Shifting programs aside, Focke-Wulf would continue with the new Höhenjäger II project, now seeking to build a truly superb high altitude fighter by taking several of the Fw 190C prototypes and equipping them with Hirth TK 11 turbo-superchargers. With the Fw 190B improvements, the 2000 hp DB 603 S, and a pressurized cockpit, it was hoped that a number of exceptional high altitude fighters could be produced, even if they could never reach the production figures of the Dora. They attempted to solve the earlier issue with the unmanageable size of the turbosupercharger by installing it partially outside of the fuselage, with an air scoop at its front. V18 received the necessary modifications and flew in December of 1942, with serious cooling problems being noted. Further modifications were made after the first several flights, most notable being that a larger oil cooler was mounted, the tail was enlarged to improve high altitude control, and the next prototype, V30, was re-equipped with a four bladed Schwarz propellor. Their extreme high altitude performance was superior to the C, with the aircraft reaching a speed of 670 km/h at 11 km, though they were proving far more temperamental. Turbine and engine issues continued to cut test flights short, though more prototypes were constructed through early 1943, V29 to V33. However, turbine issues persisted, and the entire scoop set up was found to be aerodynamically poor, and the design was proving very disappointing in comparison to the fully recessed models in service with the USAAF. Its performance too was deemed inadequate, and the project was canceled.

Falling behind

Apart from expedient designs, like the GM-1 boosted Bf 109’s, German efforts to produce a high altitude fighter had largely stagnated during 1943, and by the beginning of 1944, they were at a distinct disadvantage. For the past two years, most of the aero engine industry was working hard to modify their existing models to run at their full power using the inferior materials and fuel that were available to them. Among the clearest problems this caused was with the Messerschmitt Bf 109 G, or ‘Gustav’ model, which was only finally cleared to run at its full combat power in the summer of 1943, almost two years after its introduction. Under such conditions, developing new engines was a mostly hopeless effort, and to make matters worse, Allied developments in this field were unfolding brilliantly. While Focke-Wulf and Messerschmitt had failed to deliver on their high altitude fighters, the RAF began to fully transition to the use of the two-stage Merlin in their Spitfires, while the even more powerful Griffin was in development. By the end of 1943, USAAF finally introduced the P-51B, using a licensed Packard Merlin engine, and the P-47 had seen significant performance improvements which gave it unparalleled performance above 9 km. The P-51 proved perhaps the most concerning, as it not only had the benefit of a significantly more advanced engine, but it had been designed with aerodynamic concepts that were not available to aircraft designers before the war. It was an altogether modern aircraft, whereas the German air force would remain dependent on modified versions of planes which had been flying before the war had begun. The Bf 109G had fallen behind its Western contemporaries in most areas of performance, while the Fw 190 still clung to a competitive edge in low to medium altitude engagements. At high altitudes, especially above 7.5 km, there were only a comparative handful of GM-1 boosted Bf 109G’s that could really challenge the Allies, and even then, not on equal terms.

Germany did not possess the materials needed for robust and reliable exhaust valves, bearings, or more efficient, high pressure, high temperature radiators like those on Western Allied planes. However, there were areas of hopeful improvement. Foremost was that, by the autumn of 1943, German engine manufacturers had developed nickel coatings for engine pistons to overcome corrosion problems, and had modified the DB 605’s oil scavenge system to allow it to run at its originally planned combat power. While they would not be able to produce engines as reliable as those in the service of the RAF and USAAF, it was clear that the performance disparity could be reduced. Just as crucially, improvements were being made in regards to radiator design, particularly the annular units which were being tested on the high altitude Focke-Wulf projects. The new AJA 180 on the Fw 190 series was both approaching the pressure and temperature tolerance of Allied models, and was very compact, allowing the Fw 190 to retain its aerodynamic sleekness even when it switched engines.

The Fw 190D project transitioned away from high altitude fighters when the demand for better general purpose fighters grew. Rushed into production, it had more than its fair share of blemishes but, nonetheless, was an effective successor to the earlier ‘Anton’. (worldwarphotos)

While Messerschmitt had already succeeded in producing an acceptable high altitude fighter in the GM-1 boosted Bf 109G, Focke-Wulf’s projects took a different turn. The high altitude Fw 190D project shifted focus to produce a medium altitude fighter, the Fw 190D-9, and another project would seek to build a successor to the Fw 190, the new plane being named Ta 153. The designation changed to reflect Kurt Tank’s role as the head designer at Focke-Wulf. With this new design, hopes for significant high altitude improvements were again stoked, but as had become clear by their earlier failures, such improvements could not come from any unfamiliar solutions or technically complex methods, like turbocharging.

The Successor

The Ta 153 was so designated as it was not a variant, but a successor to the original aircraft. It featured a new fuselage and wings and the occasionally troublesome electrically driven landing gear actuators were changed for hydraulically driven ones. Being almost entirely divorced from the Fw 190’s supply chain, it was thus denied for production in March of 1943, given the amount of labor and time it would take to set up tooling. A compromise model between the design and the Fw 190D was selected, designated the Ta 152.

The Ta 152C program attempted to replace the Fw 190 A&D and correct the faults of the Dora. In the end, it proved too similar to justify shifting production before the end of the war. (ta-152.de)

There were several types planned, namely Ta 152 A,B,C and H. These were standard fighters, heavy fighters for use against bombers, fighter bombers, and a high altitude interceptor. The A and B were designed to use the Jumo 213A & E, respectively, the C the DB 603, and the H, the Jumo 213E. To avoid impacting the production of the Fw 190D, the high altitude model was the first to be developed. These planes featured a hydraulic landing gear system as opposed to the electric actuators on the Fw 190, an improved vertical stabilizer from the Fw 190C program, larger wings, and a half meter fuselage extension in the rear fuselage, with the ensuing redistribution of weight helping to correct for an issue with the aircraft’s center of gravity.

While it may seem odd that they were essentially pursuing two fighter designs to succeed the Fw 190A, the Luftwaffe was desperately looking for higher performance fighters. Hopes were placed on the new Jumo 213 in the Fw 190D, and the new DB 605D in the Bf 109K, to keep pace with the Allies. The Dora was an expedient solution which could use the same supply chain as the original fighter, and the Ta 152 would be a more thoroughly improved model which would be transitioned to once the Dora’s supply chain was well established. In any case, only the high altitude Ta 152 variant was pursued with any substantial amount of resources, given it would be assigned a mission the Bf 109K and Fw 190D models were not suitable for. Jets were, of course, also quite promising, but they were still an immature technology, and it was clear that the leap from pistons to turbines could not be made in 1944.

The new fighter would be designed with both high altitude and low altitude performance in mind. To meet this challenging requirement, both the GM-1 high altitude, and MW 50 low altitude engine boost systems were to be installed aboard the aircraft. Kurt Tank selected several of the old Fw 190C prototypes to be converted for the new program, these being V18, 29, 30, 32, and 33. V33 was the first to undergo modification and was redesignated V33/U1, now featuring a three bladed VS 9 propeller, a forward fuselage lengthening of .5 meters, a rear fuselage lengthening of 0.772 m, a new high aspect wing with an area of 23.5m^2, a hydraulically actuated undercarriage, and two 20 mm MG 151/20’s mounted in the wing roots.

It first flew on July 13, 1944, and was lost after it crashed during its 36 minute test flight at Vechta. The second prototype, V30/U1, flew on August 6, and like the first, was again lost, though this time resulting in the death of its pilot, Alfted Thomas. More success was had with the third prototype, V29/U1, which flew on September 29, 1944, and the fourth, V18/U2, which flew shortly after. With pre-production beginning in November, this left them about a month to perform flight tests on their surviving prototypes.  Serious trouble with the program was encountered as late as November, when test pilot Hans Sander had to crash land his aircraft after his engine seized due to fuel starvation. It was found a hydraulic valve had been installed in the fuel line, an accident most likely a result of the aircraft’s rushed development.

The losses and damages experienced at this point in testing were threatening to seriously interrupt the pace of the project, but in the end, they rushed through development with some of the stability issues unresolved. This effectively led to the aircraft entering production with only slight adjustments from the prototypes. However, the plane was achieving good high altitude performance, both in terms of speed and ceiling. Test pilot Friedrich Schnier would fly V29/U1 to an incredible height of 13.6 km on January 20th, 1945. Beyond this, the fourth and final converted aircraft was V32/U1, which was fitted with a four bladed Schwarz propeller and the new MG 213 revolver cannon. It first flew in January of 1945, though none of the equipment would be worked into any production aircraft.

The eccentric profile of the aircraft, with its high aspect ratio wings. (destination’s journey)

The H was unique among the Ta 152 series, with its long, high aspect wings designed for high altitude use, a pressurized cockpit, and the installation of both the GM-1 high altitude, and MW 50 low altitude boost systems. While together, they promised incredible performance at any height, GM-1 was never carried aboard any of the operational fighters due to its container’s adverse effects on stability. Eager to have this aircraft as soon as possible, Focke-Wulf sprinted through its development, and the Ta 152H entered pre-production in November of 1944. The extremely rapid pace of development was emblematic of the very desperate situation the German air force was in at the time. This resulted in the delivery of an aircraft that was effectively unfinished.

The Ta 152H-0 entered service without several of the key features that the plane was set to carry, lacking the outer wing fuel tanks, and the engine boost systems. As such, it was considerably lighter, and better handling than the planned production model, but without the boost systems, it was much slower.  For the time being it judged necessary, as there were serious weight distribution issues with wing fuel tanks and boost systems aboard. While it was designed with wing tanks, GM-1, and MW 50, the production model of the aircraft would not be permitted to fly with all three. In the end only the MW 50 and the wing tanks were permitted to be used together, but the GM-1 system would prove more troublesome. A stop gap solution late in the war would allow for the use of GM-1, but only GM-1. By the time the war ended, there was still no solution on how all three pieces of equipment would be added to the plane without jeopardizing its flying characteristics.

It was in this rough state when it was delivered to the Luftwaffe for testing in December. Due to supply chain issues, production was slow and the aircraft were finally delivered to the Luftwaffe until January 27, 1945.

Operational History

Given their very late introduction during the war, the Ta 152H saw very little action and its combat record is extremely limited. The aircraft was only supplied to the Stab, the squadron staff group, and Gruppe III of JG 301, a dual night and day fighter squadron which transitioned to them from Fw 190A-8’s on January 27. The squadron had a good pool of experienced pilots already familiar with Focke-Wulf aircraft, though their mechanics would have a far more difficult task, as the Ta 152H-0 had been pushed into service without maintenance manuals. At the airfield at Alteno, they received 11 aircraft, with 16 others having been destroyed or damaged on the ground before they could reach the unit. Familiarization and training proceeded until the end of February and was not without incident. One aircraft (150037) was lost in a training incident, a second damaged but repaired, and serviceability fell from 75% to 30% after an incident with water contaminating fuel supplies. The squadron would go on to receive several more aircraft before rebasing to Sachau when Alteno was overrun. They would attempt to engage Allied bombers on March 2, but the 12 Ta 152H’s would fail to reach them, as they were attacked by the Bf 109s of another squadron which mistook their unfamiliar planes for the enemy. No aircraft were lost in the engagement. A second high altitude interception against a DeHavilland Mosquito was also attempted, though engine trouble forced the pilot to return to base before contact was made.

One of the only photographs of Ta 152H’s in operation with JG 301. (destination’s journey)

The unit rebased again to Stendal near Erfurt, where they joined JG 301’s Gruppe II, during which one aircraft was lost, and the pilot, Jonny Wiegeshoff, was killed on the landing approach. This was believed to be the result of the propeller reduction gear failing and becoming stuck in an almost feathered position. By March 14th, the understrength unit was supplied with several Fw 190A-9s. Outnumbered and with little security, the Ta 152H’s often flew top cover for the rest of the unit during what few operations were undertaken. On April 10, Erfurt was contested, and during the fighting, the eight serviceable Ta 152’s engaged a flight of fifteen P-47’s near Brunswick, resulting in one victory claim.

Gruppe III’s last actions were conducted from Neustadt-Glewe. On April 15th, the unit suffered its first combat loss. During operations that day, four Ta 152s sortied to attack a pair of RAF Hawker Tempests engaging in a low level sweep. According to Obfw. Willi Reschke, the Ta 152H in the number two position, flown by Obfw. Sepp Sattler, suddenly lost control and crashed before contact was made, seemingly suffering a fatal malfunction, while other accounts claim he was brought down by one of the RAF Tempests. The remaining two Ta 152’s engaged the Tempests of No. 486 Squadron. In the ensuing battle, Obfw. Willi Reschke entered an intense, low level dogfight with one of the Tempests. Near the beginning of the engagement, he fired on and struck the tail of a Hawker Tempest flown by Lt. Mitchell, his gun’s electrical circuit seemingly failing shortly after. However, when Mitchel attempted to turn away from his opponent, he lost control of his damaged aircraft and crashed. Reschke swore by the low speed maneuverability of the Ta 152, which he felt was critical in this engagement, and his survival through the last days of the war. The Ta 152H flown by the Schwarm leader, Oberstleuteneant Fritz Auffhammer, suffered an engine failure, though the pilot successfully restored power and returned to base with his supercharger broken. Sattler and Mitchel were both buried at a cemetery in Neustadt-Glewe.

The last actions of the squadron were in the last stages of the Battle for Berlin, and on April 24th, the Ta 152s and Fw 190As of the IInd and IIIrd Gruppe attacked Soviet positions and engaged Yak 9’s. The final mission was flown over Berlin in poor conditions, and during an engagement with a flight of four Yak 9’s, Hauptman Hermann Stahl was killed during the engagement, with the four Yak-9’s being claimed by the unit. After the surrender, the unit rebased to Leck in Schleswig-Holstein, where they were disbanded and one of the serviceable Ta 152H’s was transferred to England by the RAF so that it could be evaluated. A second Ta 152H was also claimed by the USAAF for evaluation purposes, the plane being another H-0 which likely belonged to a testing unit at Rechlin.

One of the only serviceable planes was taken to the UK for testing. The other was taken in hand by the US. (Alessandro Orseniga)

In all, the Ta 152H was never actually used for any high altitude combat operations and its service was restricted to a single under strength unit. With at most ten victories and four operational losses, it is difficult to give any appraisal for its performance from its brief career with JG 301. Obfw. Josel Keil, was the only pilot to qualify as an ace on the Ta 152H, and together with Willi Reschke, who had two credits in the Ta 152H, and 24 in other aircraft, held nearly all of the aircraft’s combat credits between them.

Handling and Flying Characteristics

While the Ta 152H’s combat record leaves a lot of questions left unanswered, most pilots who had the chance to get behind the controls of the aircraft can at least agree that the aircraft flew very well. Among its most famous advocates was Royal Navy Test pilot Eric Brown. He would praise its excellent climb performance, maneuverability at high altitude, stability, and good landing characteristics. His only negative remarks were that its roll rate was reduced over the older Fw 190A, that its stick forces were notably heavier, and that its wheel brakes were still awful and prone to fade after a few moments of use. He otherwise considered it an excellent aircraft and the best high altitude piston engined fighter he had flown, comparing it favorably to a Spitfire Mk IXX. It must be noted that he misidentifies the aircraft as an H-1 in his book, and not the substantially lighter H-0, which is visually identical.

Captain Brown’s remarks are matched by those of the pilots who assessed the aircraft in the Stab and III/JG 301. The Ta 152H-0 had the best evaluation received by a front line operator of a Focke-Wulf aircraft. The aircraft possessed most of the best qualities of the earlier Fw 1,0D-9 without having its poor accelerated stall characteristics. While still described as uncomfortable like the Fw 190D it was so similar to, it was much improved and less prone to the aggressive snap rolling. So, while the aircraft was less maneuverable, generally speaking, most pilots were more comfortable pulling harder turns. In tests at the unit, some new pilots in Ta 152H’s were able to turn with seasoned pilots in Fw 190A’s. Take off runs were short, and the landing approach could be conducted at low speeds. Generally speaking, it was a fairly forgiving aircraft. The only negative notes on the aircraft were from the findings of the Rechlin Test Center, which found the aircraft became seriously unstable in dives exceeding 600 km/h and that level flight required excessive trimming of the horizontal stabilizer.

The enlarged tail and redesigned wings helped give these aircraft better handling characteristics than the Fw 190D. (Grafiq)

The stick forces were notably fairly high, but they were harmonized well, and the push rod control system ensured inputs were very responsive. Stability about the vertical axis was poor, and there was a tendency to skid. This tendency grew worse at higher altitudes and motivated them to install a level flight autopilot. The aircraft possessed good visibility to the back, sides, and rear, with the view over the nose being mediocre to poor. The controls were placed conveniently, with the instrument panel layout being clean and easy to read.

Most of its good qualities were not found in the fully equipped H-1 production model of the aircraft. Numerous problems were encountered when the full set of engine boosting equipment and fuel tanks were installed and filled. The added weight of the boost systems and wing tanks was substantial, and asymmetric. The GM-1 system and the wing tanks were particularly problematic, and the aircraft was unstable if the GM-1 container and fuel tanks were filled. Stability with the GM-1 system was only possible with a ballast kit, empty wing tanks, the removal of the MW 50 system, and a set fuel limit for the rear fuselage fuel tank. These issues were not resolved by the time the war ended, and there was no way the aircraft could use any combination of these systems without seriously jeopardizing its flying characteristics. MW 50 was usable aboard only the H-1 production model, but it may not have been available to JG 301 in the field. The squadron was still mostly composed of BMW 801 equipped Fw 190A’s which did not use the system.

Mechanics generally found the aircraft easier to maintain than the Fw 190, however there were some issues. The new hydraulic system for the landing gear was experiencing teething and quality control issues. The position of the landing gear wheel well was also found to be at issue, as when launching from damp conditions, the propeller cast mud and water into the well, which made its way inside the wing. This caused issues with the hydraulic systems and the autocannons fitted in the wing root.

Comparisons with contemporary fighters

The Ta 152H represented a leap in Germany high altitude fighter design, though not necessarily one that took them beyond the competition. (flugrevue)
Aircraft (manifold pressure) Speed at Sea Level (km/h) Speed 3050 m (10,000 ft) (km/h) Speed 6096 m (20,000 ft) (km/h) Speed 9144 m (30,000 ft) (km/h) Speed 9.5 km (31,168 ft) (km/h)
Ta 152H-1 (1.92 ata) 580 640 690 725 732
Fw 190D-9 (1.82 ata) 611 645 689 653 645
P-51B-15 (75″ Hg) 616 675 709 688 685
P-47N-5-RE (72″ Hg) 587 643 708 740 759
P-47M (72” Hg) 587 646 701 753 762
P-38L (60” Hg) 550 608 646 663 659
Spitfire Mk 21 (+21 lbs) 592 658 700 704 703
Me 262 A-1a 800 x 870 845 x

*The Ta 152H-1 could reach a maximum speed of 760 km/h at 12.5 km using the GM-1 boost system. While it was never cleared for operational use, on paper, it made the Ta 152H the fastest fighter at that altitude. The Fw 190D-9 represents a late model, having received an MW 50 boost system, as was available near the end of 1944.

The Ta 152 entered service on a battlefield where the Western Allies already had high altitude supremacy, and had a number of improved designs that had yet to make their debuts by the time the war in Europe was ending. By January of 1945, the German air force was no longer dealing just with long range escort fighters over its own soil, but virtually every fighter the Allies could throw at it, such as P-47’s, Spitfires of several marks, La-7’s, and Tempests, just to name a few.

Fw 190D-9 (Graphiq)

Against its contemporary Fw 190D-9 counterpart, it is clear that the Ta 152H did not represent a comprehensive upgrade. The Dora shared much of the same fuselage, though it retained the wings and tail sections of the older Anton series fighter, and it carried the Jumo 213A engine designed for use at lower altitudes. In regards to linear speed and acceleration below 6 km, the Dora roughly matched or exceeded the Ta 152H. This, however, was not the case at higher altitudes, where the high altitude specializations of the fighter showed their worth. The Ta 152H was known to be more maneuverable in flat turns and much more forgiving in most aggressive maneuvers, a result of its high aspect ratio wings which lacked the less than ideal tendency for snap rolling without much warning that the older Fw 190’s were known for. In a dive, the Dora was notably superior, as the aforementioned wings of the Ta 152H made it notably unstable at high speed. The H-1 carried, but was not cleared to use GM-1, nor does it seem they would have ever been supplied with the mixture. This is a discrepancy of several hundred kilograms, leaving the true climb performance of the aircraft somewhat ambiguous, with a claimed 20 m/s at sea level without MW 50.

The P-51B’s and D’s had marginal differences in performance They were among the most aerodynamically clean fighters of the war, boasting an extremely streamlined fuselage, laminar flow wings, and a radiator scoop which produced thrust that offset upwards of 90% of its own drag. To increase maneuverability in high speeds and in power dives, the control surfaces were internally sealed and used a diaphragm to reduce stick forces. The engine was a Packard Merlin V-1650-7 with an intercooled, two stage, two speed supercharger. Even though the engine was actually geared for lower altitude use than its predecessor, the combination of these features made the aircraft a very fast, maneuverable fighter which could boast of high performance at most altitude ranges.

Against the Ta 152H-1, the Mustang held to a higher top speed at low to medium altitude, better maneuverability at high speed, and far better dive performance. At extreme altitudes, the H-1 outstripped the Mustang in top speed, and across most altitudes would have had better low speed maneuverability. The high aspect ratio wings of the Ta 152 both gave it better handling at high altitude, and much improved stall characteristics over its predecessors down low. Curiously enough, both the Ta 152H and the Mustang were far more maneuverable than their wing loading would suggest, a result of high aspect ratio and laminar flow wing designs, respectively. However, in the Ta 152’s case, this came at the cost of a slower roll rate, and unstable high speed dive characteristics. While the Ta 152H could prove an exceptionally challenging high altitude opponent to all of the contemporary Allied fighters, it was a competitive, but not particularly impressive aircraft at lower altitudes. Performance wise, it could be said to fly like a more maneuverable, if slower, Fw 190D when at lower altitudes.

There is of course the story of Kurt Tank himself escaping a pair of P-51’s at low altitude in a Ta 152 prototype. Near the end of 1944, the designer himself was flying one of the prototypes to a conference in Cottbus, Germany, where he was happened upon by two P-51’s. Using the MW 50 boost system in the aircraft, Tank slipped away from his pursuers and arrived in Cottbus unscathed. Some laud this encounter a sign of the aircraft’s superiority, however, it is not a useful measure of the performance of any of the combat models of the aircraft. At Kurt Tank’s instruction, the prototype in question was unarmed and, more than likely, carrying no armor plate, which would have made the aircraft substantially lighter than any operational Ta 152H fighter.

The Spitfire Mk 21 represented the final evolution of the wartime Spitfire, by then nearing its tenth year in the air. A far echo from the Mk I, the 21 featured a vastly more powerful Griffin 61 engine. Much like its late Merlin powered predecessors, it possessed an intercooled, two stage, two speed supercharger. Unlike them, it was massive and much more powerful. After incorporating structural improvements and modifying controls for high speed, the Spitfire aged perhaps the best of any fighter of the war. Compared to the Ta 152H, it lacked the sheer distance in top speed performance of the P-51, but more than challenged the Focke-Wulf in linear speed and climb rate across most altitudes. However, at and above 7 km, the 152H had a confident advantage in speed and maneuverability.

The P-47N represented the final evolution of the Thunderbolt. Though not destined for Europe, it performed similarly to the P-47M which debuted in combat roughly the same time as the Ta 152H. (wikimedia)

Compared to the most modern Allied high altitude fighters, the Ta 152H lost most of its edge. The P-47N and M represented the final evolution of the American high altitude fighter, featuring a new 2800 hp, R-2800 turbocharged engine, and a variety of aerodynamic improvements to increase control at high speed. By the late Summer of 1944, the Western Allies had already gained air superiority over Europe, and so the new aircraft was stockpiled in the US for use in the Pacific, with the first deliveries being made in September of 1944. There was a similar performing model in Europe, the P-47M, though it was a limited production aircraft designed for chasing V-1 flying bombs and other high speed targets. Teething issues would keep it from entering service roughly until the Ta-125H did, in March of 1945. In the end though, the Luftwaffe had become so degraded that clearly no new updated models would be required and the performance increases would not justify the effort to refamiliarize pilots and maintenance personnel.

In terms of top speed, the P-47M&N handily outperformed the Ta 152H at all altitudes, the only exception being at extremely high altitudes when the Ta 152H employed GM-1. In contrast, the Focke-Wulf enjoyed a better climb rate and was likely the more maneuverable of the two, although it was certainly less capable in a dive. The late war Thunderbolts were certainly the fastest high altitude fighter which saw combat, the Ta 152H’s of JG 301 never having carried GM-1.

The P-38L was the last fighter variant of the Lightning fighter, the first model having been in service prior to the US entry to the war. With its turbo supercharged Allison engines, it was among the first fighters of the war that was designed for high altitude use. However, by the end of the war, it left something to be desired in terms of both its top speed, and like the Ta-152H, its high speed dive performance. Its low critical Mach number meant that the plane encountered compressibility at lower speeds than all of the fighters presented here. At high speeds and altitudes, the plane locked up and would remain uncontrollable until its high speed breaks were deployed, or it had descended into lower, denser air. Of all the Allied high altitude fighters, the Lightning compared fairly unfavorably with the Focke Wulf.

Most easily glossed over is the performance compared to jet fighters, which by the time the Ta 152H was introduced, could not exactly be called new. The Messerschmitt 262 had re-entered service in November of 1944 after earlier operational problems, and once training and maintenance programs were revised, the plane quickly proved itself. While it was slow to accelerate and climb, it was unapproachable in terms of top speed. Extreme high altitude use of the temperamental Jumo 004 turbojet engine was limited, though as a means of attacking high altitude formations of Allied bombers, it was by far the best equipped aircraft Germany possessed. Its slow acceleration meant that any energy-demanding maneuvers were largely off the table, but when flown by a pilot that understood its strengths, the plane was untouchable save for when it was taking off or landing. Though largely an issue post war, the Me 262 demonstrated the difficulty in justifying further piston engine fighter development at this point in aircraft development.

The Ta 152H began production after the Me 262 jet fighter had already entered service, so it, and many other programs, had to compete with it for resources. As the turbojet was already showing to be the future of fighter design, the Ta 152 was difficult to sell to the Luftwaffe. (I.PINIMG)

Overall, the Ta 152H certainly was not a Wunderwaffe by any means. At all but the highest altitudes, the aircraft was not a particularly better performer than its preceding, and much more numerous, Fw 190D counterpart. Even at extreme altitudes, it more than had competition in the form of the Thunderbolt N and M, which not only outstripped it in performance in a number of areas, but beat it into production by several months. It’s only truly exceptional performance was achieved using a high altitude engine boost system that was never made available to the unit carrying the aircraft, and in any case, it would have required a redesign of the aircraft to be used properly. Nevertheless, it represented a stark improvement in high altitude performance over previous German fighters. It too, could boast of extreme maneuverability at high altitudes, even if it didn’t lead the pack in pure speed. Top speed aside, its wings lent it a great degree of maneuverability at high altitude, and its overall performance at and above the altitudes Allied bombers flew at was considerable. This is also to say nothing of its trio of cannons; two 20mm MG151/20’s and its single 30mm MK108, which leant it incredible striking power. While the incorporation of the Jumo 213E, MW 50, and on paper, GM-1, did not produce the pinnacle of fighter design, the result was still a capable high altitude interceptor capable of engaging the highest flying targets of its day.

Construction

The construction of the Ta 152H’s fuselage was essentially that of a modified Fw 190A-8. The fuselage was largely the same with the following modifications: the forward fuselage was lengthened by 0.772 m in order to fit in a Mk 108 autocannon, the wing connecting section was moved forward 0.420 m to correct for the center of gravity, and the rear fuselage was lengthened by 0.5 m. The leading edge of the tail was exchanged for that on the Fw 190C, being considerably larger. Given the deteriorating situation near the end of the war, the new tail surfaces were wood, rather than metal skinned. The fin and rudder were enlarged for better control, with the new surface area of the tail stabilizers measuring 1.77 m2 for the vertical and 2.82 m2 for the horizontal. The changes to the fuselage necessitated strengthening, which saw some duralumin framing elements replaced with steel. In order to reduce the number of assembly jigs they needed to produce, the forward fuselage extension was bolted through the former engine attachment points.

The Ta 152H-1 featured all the fuel tanks pictured here, the preproduction H-0 had only those in the fuselage. (Deutchesluftwaffe.de)

The Ta 152H-1 featured all the tanks pictured here, the preproduction H-0 had only those in the fuselage. (Deutchesluftwaffe.de)

The wings were entirely redesigned from the Anton and changed to a high aspect model which increased the wingspan to 14.4 m, and to an area of 23.3 m2. Structurally, it remained a monocoque structure, but its rear spar and leading edge were used to absorb transverse forces and it was structurally reinforced with additional stiffening ribs. The landing gear were the same as the Fw 190A-8’s, but they were hydraulically and not electrically operated. They mounted 740 mm by 210 mm wheels to accommodate the increased weight of the aircraft. The inboard section of the wing mounted an MG 151/20 autocannon with provisions for 175 rounds of ammunition each.

Clean instrumentation, a high level of engine automation, and good visibility made the Ta 152H a fairly straightforward aircraft to fly. (destination’s journey)

The aircraft possessed a pressurized canopy to reduce the physiological stresses of high altitude flight. It was a very rudimentary system, with the cockpit rivets being sealed with DHK 8800 paste, and the sliding hood being sealed by means of a cylindrical rubber tube liner. Pressurization was regulated by means of a 1 liter air bottle supplied by a Knorr 300/10 air compressor which was geared to the engine with no intermediate gearing. The system was engaged at 8 km and maintained a constant .36 atmospheres. To prevent windscreen fogging, it was double-paned, with silica packets installed in the gap. Quality control issues saw varying effectiveness at altitude. On the record setting flight, Friedrich Schnier reported the system leaked badly above 12 km and shortly after he suffered joint pain, impaired vision, and numbness in his extremities due to low air pressure.

The Ta 152H carried an armament of two MG 151/20 20 mm cannons in each wing root and a centerline MK 108 30 mm cannon which fired through the propeller hub. The 20 mm guns were supplied with 175 rounds per gun, and the 30 mm with 90. The gunsight was the standard Revi 16b sight, which was eventually supposed to be replaced by the new EZ 42 gyroscopic sight which, when properly used, gave the pilot an accurate gunsight lead against his target. The aircraft was well armored with two engine plates, and six to protect the pilot, with a combined weight of 150 kg. The 8 mm plate behind the pilot was judged inadequate, though plans to increase its thickness to 15 mm were not carried out. A single hardpoint could be attached to the underside of the aircraft to install a 300 liter drop tank, but there were no provisions for carrying bombs.

The engine was a 35 liter Jumo 213E inverted V-12. Originally developed from the Jumo 211, which saw heavy use in bombers much earlier in the war, the new Jumo 213 was what most of the Luftwaffe’s hopes were placed on to compete with newer, more powerful Allied engines. It featured a new AJA 180 streamlined annular radiator that supported the oil and engine coolant. Critically, it was able to operate at significantly higher temperatures and pressures than older models, though not quite at the standards of the Western Allies. However, unlike Allied models, the Jumo was heavily automated. The Bediengerat, or control device, was a hydro-mechanical computer that managed the propeller RPM, mixture, supercharger speed, and radiator based on the pilot’s throttle inputs. This helped to relieve the pilot’s workload, as the Kommandogerat did on the BMW 801 powered models.

The Jumo 213E was the high altitude model which featured an intercooled, two stage, three speed supercharger. To further improve on high altitude performance, the aircraft would use a GM-1 nitrous boosting system. The system consisted of an 85 liter tank behind the pilot, and a crescent shaped liquid nitrous tank that sat at the right front side of the cockpit. The mixture was fed into the supercharger by a pump when the system was activated. As an oxygen carrier, the job of the nitrous is to provide an oxygen rich mixture to the engine when the supercharger is operating at altitudes where it is unable to provide the compression, and thus enough oxygen, needed to maintain a high manifold pressure. For the Jumo 213E, this was above 11 km. The drawbacks of the system were its uselessness below 11 km, and the bleed off of the evaporating liquid nitrous, which prevented it from being efficiently stored aboard the aircraft beyond several hours. Unlike its use on other aircraft, like Bf 109’s and Ju 88’s, the position of the nitrous tank aboard the Ta 152H proved dangerous, as it severely impacted the plane’s stability. It is unlikely the system would have been very effective without a major redesign of the fuel and mixture tanks, as even with a ballast kit that stabilized a GM-1 carrying plane, the aircraft could not carry anywhere near its full fuel load or its MW 50 boost system. While, on paper, the system promised unparalleled performance at extreme altitudes, it was almost unusable given its unstable configuration.

The MW 50 system was the low altitude boost system. It consisted of a 70 liter tank in the port wing containing MW 50, being roughly 49% methanol and 49% water, with the remainder being an anti corrosion measure. When active, the solution was pumped into the supercharger. The system was designed to boost engine power and overcome the less than ideal quality of German aviation fuels. Poor detonation characteristics, especially of the lower octane B4 fuels, forced the Germans to run at lower manifold pressures and thus lower power to avoid damaging their engines. Methanol boosted the octane rating of the fuel-air mixture entering the manifold, and the water cooled the mixture, with both factoring to bring major improvements in engine power via their combined anti-detonation, or knock, effects. The system made its debut in the summer of 1944, and was essential in allowing the later Bf 109G and Fw 190D series aircraft to stay competitive with their Allied counterparts. However, it was not without its drawbacks. It could not be used effectively above around 6 kilometers, and it was highly corrosive, severely limiting the lifespans of corrosion prone German engines. Aboard the Ta 152, it was to be installed in either a 70 liter wing tank or a standard 115 liter tank behind the pilot.

The Jumo 213E Kraftei. The entire assembly was bolted to the front of the fuselage and streamlined engine swaps. (ta152.de)

The engine had a bore and stroke of 150 mm and 165 mm, a compression ratio of 6.5:1, and a dry weight of 1040 kg. It differed from the standard model in that it had a slightly smaller bore, and the larger supercharger assembly and the associated intercooler added some 300 kg. It used B4 fuels which had a minimum octane rating of 87. The engine drove a constant speed 3.6 m VS 9 wooden propeller with a reduction gear of 1:2.40, and produced a maximum of 1753 PS (1729 hp) at sea level and 1260 PS (1242hp) at an altitude of 10.7 km. The oil header tank sat atop the front of the engine, and the coolant tank sat at the rear. On the Jumo 213A, these had a capacity of 55 and 115 liters respectively. The entire engine assembly was a Kraftei, or power-egg, consolidated unit, allowing the engine and its associated coolant systems to be easily removed or added to the aircraft.

Its radio and navigation systems included the FuG 16ZY ground control transceiver to allow it to be tracked and directed from ground based stations, a FuG 25A erstling IFF, and a FuG 125 radio direction finder for beacon homing. Some aircraft were also fitted with a K 23 level autopilot to reduce fatigue when flying the aircraft at high altitudes and in poor weather. The autopilot was accompanied with a heated windscreen and a FuG 125 Hermine radio navigation system as part of the R11 Rüstzustand equipment package.

Production of the Ta 152H

The Ta 152H was introduced in an environment where all quality control measures had already been cut down for every aspect of production. The lack of skilled labor and poor materials meant that building a reliable aircraft engine in Germany had become almost impossible by the spring of 1944. Slave labor and foreign, drafted workers had become the base of the labor pool, as most of Germany’s factory workers had been drafted to fight, resulting in a sharp decrease in quality. This was not only a result of poor working conditions and the inexperience of the workers, but sabotage became widespread, especially among those pulled to work from concentration camps. Even more desperate measures began to be instituted in the summer of 1944, as the re-use of parts from salvaged aircraft became more commonplace, and engine test runs were ever more limited to conserve dwindling fuel supplies.

The first Ta 152H-0 was completed in November of 1944 after considerable delays due to several sets of blueprints being found to be inaccurate, and sets of jigs had been lost in France the previous summer. The first planes were sent to the Rechlin test center in December of 1944, while Focke Wulf considered how to accelerate production. While doing so, they were hobbled when the Jagerstab, which managed strategic fighter production, shifted more and more resources to jet fighters and older, established piston engined fighters. Ta 152H production standards continued to decline in the midst of the widespread economic collapse of Germany. Near the end of January 1945, it became almost impossible to build any more Ta 152H’s, as the decentralized production system began to collapse, the rail system became unusable, and the wing and fuselage production center at Pozen was overrun by the Allies.

By the war’s end, approximately 60 Ta 152H fighters had been completed at the Focke Wulf facility at Cottbus. The series suffered extreme quality control issues in service with JG 301, which included supercharger surging and the failure of a propeller reduction unit, which resulted in the death of a pilot. In April of 1945, the plans were sold and shipped to Japan, where unsurprisingly, there was no new production of the aircraft.

Conclusion

The sole remaining Ta 152H is in storage at the Smithsonian Air and Space Museum, where it awaits restoration. (Smithsonian)

The Ta 152H is often seen as one of the great ‘what if’s’ of the Luftwaffe, but in reality, the aircraft was a good, rather than truly exceptional fighter. While on paper, the Ta 152H was to be an incredible aircraft at high altitude, it’s rushed development, and hasty introduction into service saw it fly without the GM-1 boost system that it needed to achieve these feats, and in a rather regrettable state in terms of build quality. It stacked up well against many of the older aircraft in the theaters it fought in, like the Yak-9, Spitfire Mk IX, or the P-38L, and against its contemporary Allied rivals, it was a competitive fighter at high altitudes.

Specification:

Specification Ta 152H-0 H-1
Engine Junkers Jumo 213E Junkers Jumo 213E
Engine Output 1753 PS, 2050 PS w/ MW50 1753 PS, 2050 PS w/ MW50
Empty Weight 4031 kg
Loaded Weight 4730 kg 5220 kg
Maximum Range 2000 km
Maximum Endurance 3.3 hrs
Maximum Speed [At altitude] approximately 720 km/h [10.9 km] 760 km/h w/GM-1 [12.5 km]
Service Ceiling 15 km w/ GM-1 (estimated)
Armament 1×30 mm MK 108, 2×20 mm MG 151/20 same
Crew 1x pilot same
Length 10.82 m 10.82 m
Wingspan 14.44 m 14.44 m
Wing Area 23.3 m^2 23.3 m^2
Height 3.38 m 3.38 m

 

Variants:

Ta 152H-0: Pre-production model, no wing fuel tanks, no MW 50 provisions, GM-1 capability but never cleared for operational use.

Ta 152H-0/R11: Poor weather pre-production series with level autopilot. Most pre-production aircraft were built in this configuration.

Ta 152H-1: Production model, wing fuel tanks, 85 liter GM-1 provisions but not supplied due to operational concerns. 70 liter MW 50 low pressure system installed. Fuel tankage increased from 595 liters to 995 liters with unprotected bag tanks in wings.

Ta 152H-1/R11: Poor weather model, autopilot. Most production aircraft were built in this configuration.

Ta 152H-1/R21: Equipped with Jumo 213EB intercooled engine, high pressure MW 50 system installed. Not operational.

Ta 152H-1/R31: Jumo 213EB, ballast kit to allow GM-1 use. No MW 50 and fuel capacity restricted. Not operational.

Ta 152H-2: FuG 15 radio set instead of FuG 16. Canceled in December 1944.

Ta 152H-2/R11: Bad Weather model.

Ta 152H-10: Photoreconnaissance model based on H-0.

Ta 152H-11: Photoreconnaissance model based on H-1.

Ta 152H-12: Photoreconnaissance model based on H-2.

Illustrations

The unique paint scheme of this aircraft was an identification measure, as the plane was largely unknown to German Flak and fighter crews. It was flown in this state to a conference.

 

 

Credits

  • Article written by Henry H.
  • Edited by  Henry H. & Stan L.
  • Ported by Henry H.
  • Illustrated by Hansclaw

Sources:

Primary:

Aeroplane and Armament Experimental Establishment Boscombe Down Spitfire F. Mk. 21 LA.187 (Griffon 61) Climb and Level Speed Trials. 10 October 1945.

Einmotorige Jäger: Leistungsdaten, 1.10.44

Ersatzteil-Liste TA 152. Konstruktionsgruppe 7 Triebwerksanlage. Focke-Wulf Flugzeugbau G.M.B.H. Bremen.

Fighter Offensive Performance at Altitude Model P-47N-5RE Engine P&W R-2800-73 GP=45:1 Propeller-4 Blades- 13’0” DIA. (Curtis 836) War Emergency- 2800/2800 S.L. to Critical Altitude G.W.=13962 LBS. Republic Aviation Corporation. Farmingdale L.I., New York.

Horizontalgeschwindigkeit über der Flughöhe mit Sonderleistung. Leistungsvergleich Fw 190 – Ta 152. Focke-Wulfe Flugzeugbau G.M.B.H. 3.1.45

P-51B-15-NA 43-24777 (Packard Merlin V-1650-7) Performance Tests on P-38J, P-47D and P-51B Airplanes Tested with 44-1 Fuel. (GRADE 104/150). 15 May, 1944.

Smith F., M.A. and Brotherton J. Note on the performance in flight of the German jet-propelled aircraft Messerschmitt 262, Heinkel 162, and Arado 234. Royal Aircraft Establishment, Farnborough. October 1945.

Secondary:

Brown, Eric Melrose. Wings of the Luftwaffe. Hikoki, 2010.

Douglas, Calum E. Secret Horsepower Race: Second World War Fighter Aircraft Engine Development on the Western Front. TEMPEST, 2020.

Green, William. The Warplanes of the Third Reich. Doubleday & Company. 1970.

Harmann, Dietmar. Focke-Wulf Ta 152 the Story of the Luftwaffe’s Late-war, High-Altitude Fighter. Schiffer Military History. 1999.

Smith, J. & Creek, Eddie. Focke-Wulf Fw 190, Vol. 3: 1944-1945. Specialty Pr Pub & Wholesalers. 2015.

Smith, J. & Creek, Eddie. Me 262 Volume Two. Crecy Publishing. 2007.

Weal, John. Focke-Wulf Fw 190 Aces of the Western Front. Osprey Publishing. 1996.

Boeing Model 299G

United States of America

Heavy Bomber Design Study

Model 299G as it appeared in a microfilm document from a private collection on the B-17C. Note this is a recreation. (Bill Stanczak)

Introduction

There are very few planes in military and aviation history that have garnered as much attention or popularity as the Boeing B-17 “Flying Fortress”. The aircraft has been called by some “the best bomber of the Second World War”, although there are other contenders for that title. Opinions aside, one cannot dismiss the impact of the B-17 on military history and the evolution of strategic bombing. The development of the B-17 initially started with Boeing Model 299, often incorrectly called the Boeing XB-17 in various sources. Surprisingly, the B-17 was initially not selected for production, as the Model 299 prototype was destroyed in an accident and the US Army Air Corps’ limited budget did not allow for the purchase of the more expensive bomber. As this is such a popular aircraft, one would assume that quite a good portion of what there is to know about the plane and its development has already been researched, and documented. However, as is often the case, there are always discoveries waiting to be found, such as one particular obscure variant of the B-17, the Boeing Model 299G

To say that there is little to no information on this Model 299G would be quite an understatement as, aside from a few drawings, there is nothing that indicates why this aircraft was designed and what its exact purpose was. However, after studying the documents as well as consulting with several well-known aviation experts, it has become somewhat clear that what the Model 299G represents is not just an attempt to create a new and more effective variant of the B-17 based on the already in-production B-17B but, in fact, was a design concept that proved extremely influential in the design of the B-29 “Superfortress”.

Boeing: The American giant and a leader in aircraft design

The Boeing Company exemplifies the idea of rising from small beginnings. It was founded in 1916 on the shores of Lake Washington by a young timber baron by the name of William Boeing, who had an interest in aircraft. The first Boeing aircraft, a seaplane, took off from the shores of Lake Washington in January 1916. However, the company did not really take off until the 1920s and 30s, when Boeing achieved many great and public feats, including designing and building the first all-steel tube fuselage with its then-innovative arc welding process and even becoming one of the first companies to build dedicated mail aircraft. It was also during this time that Boeing would design and build some of its most legendary aircraft, such as the P-26 Peashooter, which, when introduced, was considered to be one of the fastest fighter aircraft in existence.

The company would gain even more fame and recognition with its construction of the Boeing Model 247 in the early 1930s, which allowed Boeing to dominate the early modern airliner market until the introduction of the Douglas DC-2 and the later Douglas DC-3. The Model 247 was considered to be extremely technologically advanced for the time and represented Boeing’s shift to all-metal aircraft construction. Boeing received even greater fame with its development and construction of the Boeing Model 299, which later became the B-17 Flying Fortress, an aircraft that was very well-liked by the top staff of the US Army Air Corps. The B-17 design would also later allow Boeing to create several other highly influential and popular designs based on the Model 299. These designs included civilian aircraft, such as the Boeing Model 307 Starliner and the famed Boeing Model 314 Clipper, which saw great fame while flying for Pan-American Airways in the late 1930s and even saw service as a Presidential transport aircraft for Franklin Delano Roosevelt. The Model 314, while externally quite different, used the same wing structure and design as the Model 299. The Model 299 design also brought forth various military variants which would see various uses, including transport aircraft in the case of the C-108 and VB-17. The Model 299’s development would ultimately culminate with the so-called “ultimate B-17”, the B-17G, which went on to become one of the most popular and well-known variants.

The Birth of Boeing’s big bombers

The development of the Boeing B-17 began in February of 1934, with a US Army Air Corps request for proposals for a new bomber with a range of 5000 miles (8046 kilometers) and a bomb load of at least 2000 pounds (907 kilograms). This request, designated “Project A”, was only a feasibility study for a production aircraft to these requirements. Even with it being a proposal, there was a chance the aircraft would be built, and Boeing put its best designers and engineers on the project and was clearly interested in developing the design. These designers and engineers soon found success, as they were able to successfully design and later build a very good aircraft. Initially, Boeing submitted the XBLR-1 (Experimental Bomber Long Range) for this program, which was later re-designated XB-15 upon its construction. Their competitor, Martin, also submitted a project, the XB-16, but that was later canceled before it actually left the drawing board, nor was a final design for it completed. Because of this, the XB-15 would remain the only bomber built in the XBLR program and was the largest until the Douglas XB-19 was built. The XB-15, while never serving as a bomber as intended, would eventually see service as a transport under the designation XC-105 and would serve until its retirement in 1944. Following its retirement, the aircraft would be partially dismantled and dumped in the so-called “Diabalo Dump”, where it remains to this day.

The Boeing Model 299 and the B-17

 

Boeing Model 299, often incorrectly called XB-17. (National Museum of the USAF)

In May of 1934, the US Army Air Corps announced a second competition, this time for a multi-engine bomber capable of carrying a ton of bombs, having a range of 2000 miles (3219 kilometers), and capable of flying at over 200 miles per hour (173 knots or 321 km/h). Unlike the previous competition, however, this aircraft would be built and brought into limited service, with a potential for full production. For this competition, Boeing decided to design and build what, in essence, was a scaled-down Model 294 (XB-15) under the designation Model B-299. The Model B-299 took many of the base features of the Model 294 and improved on them while scaling down the aircraft. In this regard, it was much like the 294, a twin-wing monoplane with four engines, but it also combined elements of Boeing’s successful Model 247 passenger aircraft. The prototype Model 299 first flew on 28 July 1935 and was very quick to impress the US Army Air Corps as well as the assembled press, with one reporter describing it as a “Flying Fortress”, and the US War Department describing it as an “Aerial Battle Cruiser”. On August 20, the Model 299 was flown to Wright Field, where it would spend the next two months being tested against the Martin 146 and the Douglas DB-1 (B-18 Bolo), where it eventually performed above and beyond the base requirements. The 299 would eventually get the US Army’s stamp of approval as well as an order for 65 YB-17s. However, on 30 October 1935, disaster struck and the Model 299 crashed and burned on takeoff. While the official cause was deemed to be a pilot error, as the pilot had forgotten, due to the lack of a checklist, to unlock the control surfaces (it was this accident that introduced checklists as standard equipment on aircraft), the US Army would cut the order to only 13 planes, designated Y1B-17, and instead ordered the production of 133 Douglas B-18 Bolos. The reason for this decision was twofold. While the destruction of the Model 299 did impact this decision, it was ultimately the US Army’s limited budget and their lack of funding that led them to ultimately choose the B-18 Bolo, as it was the only aircraft they could really afford a large number of. Despite this setback, the US Army was still enthusiastic about the design and allowed Boeing to submit another prototype for evaluation, which they did in the form of a modified Y1B-17 with more powerful engines and a crew of 6 instead of 7.

Boeing Model 299, note the distinctive nose with a small turret. (National Museum of the USAF).

The Boeing Y1B-17 did not differ too much from the original Model 299, however, some improvements were made, including switching the engines to the more powerful Pratt and Whitney R-1820s and changing the design of the landing gear arms. It was this prototype that ultimately won Boeing the contract and would go on into production as the Boeing B-17B.

The Model 299G: A modified B-17 or Something More?

When looking at the B-17’s lineage, one will notice that the very first mass-produced variant of the bomber was the Boeing B-17B or, as the Boeing Company knew it, the Model 299E (later changed to 299M). The B-17B followed a long line of prior limited or prototype variants, including the base Model 299, later Y1B-17, and Y1B-17A. The production run of the B-17B only ran for a total of 39 aircraft before it was switched to the B-17C (Model 299H). According to the documentation and the drawings found, the Model 299G was considered to be a very heavily modified B-17B which was re-engined with the Pratt and Whitney R-2180 Twin Hornets instead of the Pratt and Whitney R-1820-51 Cyclone. Beyond this, unfortunately, the drawings give very little information on this aircraft or really what exactly it was supposed to be. However, according to historians such as Mike Lavelle, this variant may be a link in the greater chain of designs that led to the Model 345, better known as the B-29 Superfortress.

The Design of the Model 299G

Boeing model 322 study, this one lacking the forward gun position but otherwise closely related to the 299G. (Lavell)

The Model 299G is unique compared to other B-17 variants and designs based on the B-17. It shares very little similarity with the Model 299 and Model 299M (B-17B) designs it is based on. Outside of the tail section and some other components, such as the general design of the wings, the rest of the aircraft is almost a completely different design from the B-17B on which it is based. Among the interesting features is the tricycle landing gear arrangement (one wheelset in the front, two on the wings). The aircraft also features a cockpit section very similar to that of the Boeing Model 307, completely eliminating the turtle deck. It shares a similar fuselage to the Stratoliner as well, as it was designed to test the feasibility of pressurization for use in bombers. Another major aspect that stands out about the aircraft is that it appears to have been both wider and longer than the B-17, with a slightly larger wingspan. Also featured were 4 defensive weapon blisters that almost seem like a cross of those on the early B-17s and those featured on the later PB4Y-2 “Privateer”. These were situated on the dorsal and ventral sections of the waist, with the ventral one just behind the wings and the dorsal one farther aft and closer to the tail.

Boeing Model 307 Stratoliner on display at the National Air and Space Museum Udvar Hazy Center. This is the sole preserved complete example. (Smithsonian)

The Model 299G also did not feature an astrodome. Rather, it featured what appears to have been a dedicated observation area above the cockpit. Perhaps the only major similarity it shared with the B-17 was that the 299G was a monoplane and, the wheels still receded into the engine nacelles. The design, as such, does not really seem to have been that of a B-17, bearing the most similarity to Boeing’s Model 307 Stratoliner, which was later adopted into US Army Air Force service as the C-75 Stratoliner. It also more clearly resembles Boeing’s later bomber designs, such as the Model 322, which eventually led to the development of the Model 345, better known as the B-29 Superfortress.

Conclusion

Boeing Model 316, a later design study possibly derived from the Model 299G. These two, and several others would go on to influence the further development of the B-17 and B-29. (Lavell)

While, ultimately, the Model 299G never left the drawing board, it certainly represents an interesting insight into the developmental history of Boeing’s large bomber projects. Based on conversations with several Aviation historians, it has been presented as a possibility that this Model 299G could also have been a very early attempt to design a sort of “Superbomber” that members of the so-called “Bomber Mafia”, including Jimmy Doolittle and General Hap Arnold, had been searching for. This conclusion would indeed make sense, as many of the features of the Model 299G do seem to correspond with later Boeing bomber designs. It has also been suggested that the Model 299G might have been a link in the greater developmental chain of the Boeing Model 345, which eventually saw service as the B-29 Superfortess. Some, however, have also suggested that this aircraft instead represented a link between Boeing Airliner development and their Military Aviation development. However, as of this writing, there is no concrete information or documentation that directly links the Model 299G to the Model 345, though it and other projects were part of the B-29 program’s design studies. Aside from general appearance, there is also really nothing concrete to link the 299G to airliner development either. What is undeniable though is that Model 299G does offer deeper insight into the continued development of the B-17 Flying Fortress and the influence, if indirect, it had on future projects.

Variants

Model 299G – The Boeing Model 299G was designed by Boeing and based on the Boeing B-17B. It never went past the design stage and was not selected for production.

Operators (Projected)

 

  • United States of America
    • US Army Air Corps (Presumed) – The Model 299G was designed by Boeing but never made it past the design stage.

Illustration

 

Credits

  • Article written by J. Manuel
  • Edited by  Henry H. & Stan L.
  • Ported by Henry H.
  • Illustrated by Ed Jackson

Sources

Baugher, J. (1999, July 25). Retrieved from http://www.joebaugher.com/usaf_bombers/b17_1.html

The Boeing Company (2020, December 20). Retrieved from

http://www.boeing.com/history/#/legacy

Harris, S. M., & Angelucci, E. (1983). The Rand McNally Encyclopedia of military aircraft: 1914-1980. New York: Military Press.

Model 299 Crash. (2009, June 25). Retrieved from https://www.nationalmuseum.af.mil/Visit/Museum-Exhibits/Fact-Sheets/Display/Article/610002/model-299-crash/

Model 299 Press Release. (2009, June 25). Retrieved from https://www.nationalmuseum.af.mil/Visit/Museum-Exhibits/Fact-Sheets/Display/Article/610003/AFmuseum/

Lavelle, Mike. War on the Home Front: Building the B-29 Superfortress. Chester River Press, 2011.

Lavelle, Mike, and Matzelle, Liz. “Fwd Boeing 299G.” Received by Jonathan Manuel, 21 Nov. 2021

Simons, Graham M. The Boeing B-29 Superfortress: The Giant Bomber of World War Two and Korea. Pen Et Sword Aviation, 2012.

Messerschmitt Me 209

Nazi flag Nazi Germany (1942)

Experimental record-breaking aircraft

Number built: 4 prototypes

The Me 209 aircraft. Source: www.luftwaffephotos.com

In the years prior to the Second World War, in Europe, there was significant interest in the development of aircraft intended to be used for breaking various world records. International competitions and exhibitions of new aircraft technology were quite common in this period. While at first glance this may seem like a hobby or sports event, in reality, these were often used for propaganda purposes to glorify a nation’s own aviation industry as superior to those of other countries. Achieving the greatest possible speed was often regarded as a clear measure of engineering supremacy over other countries. Germany was one of these, which took up the task in the late 1930s to achieve the greatest possible speed. They successfully achieved with the Me 209, an excellent record-setter, but completely unsuited for military use.

History of the Me 209

Due to restrictions imposed by the Western Allies, the Germans were partially limited from researching certain aircraft technologies. This did not stop them, however, as German aviation enthusiasts and aircraft manufacturers found numerous ways to bypass these restrictions. In the early 1930s the German aircraft industry worked at full capacity in order to increase the production of ever-needed new aircraft designs, but also introduced a series of new technologies. When the Nazis came to power in 1933, huge investments were made in order to build one of the most modern air forces in the world. Thanks to these resources, the Germans introduced a series of excellent aircraft designs that would dominate the skies over Europe in the first years of the war.

Some of these aircraft were specially modified so that they could be reused as propaganda tools. Their purpose was to achieve as many world records as possible. On the other hand, these were never actually accepted for service. One aircraft developed by Heinkel, the He 100, managed to achieve great success by reaching a speed of 764 km/h. However, this was not enough in the minds of the leading officials of the Reichsluftfahrtministerium – RLM ( German Air Ministry) who wanted something more imposing to show to the world. Adolf Hitler himself wanted to show off the superiority of the German aviation industry. So to win worldwide prestige in aviation, in 1937 Messerschmitt was instructed by the RLM to begin developing an experimental aircraft that set the world speed record. Given its specialized nature as a high-speed record-breaker, Messerschmitt received production orders for three prototype aircraft.

Willy Messerschmitt and his team of engineers began working on such a project, codenamed P.1059 in the early stage of development, soon after the requisite was made and the first working prototype was now under the designation Me 209 V1 (D-INJR).

The Me 209 mock-up in its early development stage. Most evident is the unusually rear-positioned pilot cockpit. Source: ww2fighters.e-monsite.com

The Prototype Development

The Me 209V1 prototype made its maiden flight at the start of August 1938. This flight was rather short at only 7 minutes.  It was flown by the Messerschmitt chief engineer J. H. Wurster who was also a pilot. It was initially planned to use the experimental DB 601ARJ engine. As it was not yet available, a more orthodox 1,100 hp DB 601A engine was used instead. Almost from the start, the Me 209V1 was shown to be a troublesome design. Numerous issues were detected during flight testing. Some of these included the aircraft’s tendency to abruptly dive in mid-flight, the controls being heavy and hard to work with either in the air or on the ground, cockpit ventilation was poor, engine overheating problems were evident due to insufficient cooling, and cockpit visibility was quite limited. During landings, the Me 209 showed that it had a high sinking rate which usually led to a harsh landing, potentially causing damage to the landing gear. Despite all of this, which would in other circumstances lead to a sure cancellation of the project, the RLM officials urged that the Me 209 development should go on.

The side view of the Me 209V1 prototype. Interestingly the Messerschmitt workers did not even border apply any paint job to it. The natural aluminum color is quite evident in this photograph.

The side view of the unpainted Me 209V1 prototype. Source: ww2fighters.e-monsite.com

The second prototype Me 209 V2 (D-IWAH) was completed in early 1939. It was flight-tested for the first time on the 8th of February 1939. At that time Wurster gave up his position as the Messerschmitt test pilot to Fritz Wendel.  On the 4th of April, there was an accident where this aircraft would be lost. After a short flight, the pilot Fritz Wendel was preparing for a landing approach on Haunstetten airfield. Suddenly, and without warning, the engine stopped working and the aircraft rapidly lost altitude. In another version of this event, the engine stopped working shortly after take-off. Regardless of which event was true, the aircraft was lost but surprisingly the pilot Fritz Wendel survived the forced landing without injury.

The Me 209V2 aircraft during its construction. While it was to be used for breaking the world record, its early demise meant the V1 had to be used instead. Source: ww2fighters.e-monsite.com

In the meantime, with the loss of the V2 aircraft, the testing continued using the first prototype which was finally equipped with the DB 601ARJ engine. This engine was rated for 1800 PS on take-off, with its emergency power setting reaching 2,465 PS.

A New World Record

As the V2 was lost and the other two prototypes were still under construction, it was devised to use the V1 aircraft for the anticipated world record flight. On the 26th of April 1939, while piloted by Fritz Wendel, the Me 209V1 reached a phenomenal speed of 755 km/h. It would take nearly 30 years before the record was beaten by a modified American Grumman F8F-2 in 1969.

German Minister of Propaganda Joseph Goebbels was quick to exploit this successful flight. Goebbels propaganda machine soon published this news as a great success of the German aviation industry. To hide the experimental nature of the Me 209, in propaganda news it was renamed Bf 109R. This was also done to deceive the general foreign public that this was an actual operational fighter. Shortly after that, all further work on beating the speed record was strictly forbidden. Following this success, Me 209 V3 (D-IVFP) was completed and flight-tested in May 1939. Its flight career would end shortly as its frame was mostly used for various testing and experimentation duties.

Technical Characteristics

The Me 209 was a low-wing, all-metal, single-seat, experimental record-breaking aircraft. Unfortunately due to its experimental nature, not much is mentioned about its precise construction in the sources.

The fuselage and the wings were made of a metal frame covered in aluminum sheets. The rear tail unit had an unusual design with the rudder being greatly enlarged. This was done to help the aircraft design cope with propeller torque.

The Me 209 landing gear consisted of two landing gear units that retracted outward towards the wings. The Me 209 used a more common type of landing gear that retracted inward to the wings. To the rear, a sliding skid was placed at the bottom part of the large tail fin. The skid was connected with a spring to the tail unit and could be completely retracted to reduce the drag.

The cockpit was placed quite to the rear of the aircraft fuselage. This design had a huge flaw, as it severely restricted the pilot’s front view.  The canopy of this cockpit opens outwards to the right. It was likely taken directly from Messerschmitt’s early design of the Bf 109. In an emergency, the canopy could be jettisoned.

The Me 209 was to be powered by the DB 601ARJ engine, a twelve-cylinder, liquid-cooled V-12 engine. This engine used a Messerschmitt P8 three-bladed propeller. The engine cooling system was rather unusual. As the Messerschmitt engineer wanted to avoid using a standard radiator to avoid unnecessary drag, they came up with a new design. The engine was cooled with water, which was nothing unusual, but the way the water itself was cooled was quite a new and complicated process. The hot water steam from the engine was redistributed to the wings through pipes. Once in the wings, through a series of specially designed openings, the hot water stream would be condensed back to a liquid state. The cooled water would then be brought back to the engine, where the process would be repeated again and again. The negative side of this system was the constant loss of water due to evaporation, which depending on the conditions like speed may differ widely from 4 to 7 liters per minute. Due to this huge loss in a short amount of time, the aircraft had to be equipped with a 200 (or 450)  liter water container. With this water load capacity, the Me 209 had an endurance time of only 35 minutes.

The Me 209 cockpit canopy opens outwards to the right. This design had a flaw as it could not be left open during takeoff or landing. In an emergency, the canopy could be jettisoned. Source: ww2fighters.e-monsite.com
The Me 209 was to be powered DB 601ARJ engine which used a Messerschmitt P8 three-bladed propeller Source: aviadejavu.ru
The rear view of the Me 209V1, where the enlarged vertical stabilizer could be seen. Its purpose was to help the aircraft cope with propeller torque. Source: ww2fighters.e-monsite.com

Attempt To Develop a Combat Version of Me 209

In May 1939 the Me 209 V4 (D-IRND) was flight tested. While the previous prototypes were to be used for beating international world records, the V4 was an attempt to adopt the Me 209 for potential military use. It was not requested by the RLM but instead a Messerschmitt private venture.

This prototype would receive a military code CE-BW in 1940. Its design was modified to include new and enlarged wings. The racing engine was replaced with a military model, the 1,100 hp DB 601. Due to the limitations of the wing-mounted cooling system, it had to be replaced with conventional radiators, which were changed several times in the Me209 V4’s development. The wing design was also changed as it was somewhat larger and longer than that used on the original Me 209. These were also provided with an automatic leading-edge slat.

In addition to its new purpose, it was to be equipped with offensive armament. The sources disagree on its precise armament. According to,  D. Myhra (Messerschmitt Me 209V1) it consisted of two 7.92 mm MG 17 machine guns placed above the engine, a 2 cm cannon that would fire through the propeller shaft, and two 3 cm Mk 108 cannons to be installed in the wings.  The potential use of this wing-mounted armament is quite questionable for a few reasons. The installation of such a cannon would not be possible given the limited room inside the wings. In addition, the MK 108 would be introduced to service in the later stages of the war, years after the Me 209 V4 was tested.

Authors J. R. Smith and A. L. Kay (German Aircraft of the WW2) on the other hand mentioned that the wing armament was to consist of two MG 17 machine guns, but this had to be abandoned as there was no room in the wings for them.

During testing of the much modified Me 209V4 it was shown to have weaker general flight performance than the already produced Bf 109. Attempts to further improve it by installing a stronger engine failed, as the Me 209 was still underpowered as its airframe was designed around a phenomenally powerful engine.  Despite all this work the Me 209V4 was simply not suited for use as a fighter and thus the project had to be abandoned.

The Me 209V4 was a failed attempt to introduce to service a new and improved fighter aircraft that would potentially replace the Bf 109. It was not requested by the RLM but was instead Messerschmitt’s own private venture. Source: www.luftwaffephotos.com

The Fate of the Me 209 prototypes

Following the completion of its original goal, the Me 209V1 aircraft was given to the Berlin Air Museum in April 1940. While initially the Messerschmitt workers simply kept the natural aluminum color for the Me 209. This was not appropriate for an exhibit; it would be repainted in dark blue with its code painted to its fuselage sides. Interestingly during its brief service, the Me 209 was often nicknamed by its crew as Fliegend Eber (Eng. flight boar).

The Me 209V1 just prior to being allocated to the Berlin Air Museum in April 1940. The pilot is Fritz Wendler, and next to him it is Willy Messerschmitt. Source: ww2fighters.e-monsite.coml

In 1943 the Berlin Air Museum was hit during an Allied bombing raid and many aircraft were lost. The Me 209V1 was damaged but its fuselage was left relatively intact. It and other exhibits were moved to Poland for safekeeping, where it was simply forgotten. It was not until 1967 that Norman Wiltshire from the International Association of Aviation Historians actually discovered its remains during his visit to the Polish Air Museum in Krakow. The preserved Me 209V1 fuselage is still located at the Polish Museum, despite many attempts by the Germans to buy it back. The Me 209V3 was completely destroyed in one of many Allied bombing raids of Germany, while the V4 was scrapped at the end of 1943.

Me 209  fuselage at the Polish Aviation museum in Krakow, Poland Source: www.wikiwand.com

Japanese Interest

Despite being obvious from the start that the Me 209 would not enter production, a Japanese attaché showed interest in the project. In 1943 he approached the RLM officials with a request for technical data and that one aircraft to be shipped to Japan.  In the end, it appears that nothing came of this and no Me 209 was ever sent to Japan.

An Me 209 but not a Me 209

As the war progressed, Messerschmitt engineers were trying to design a new piston-powered aircraft that would replace the Bf 109. That would initially lead to the creation of the Me 309 which proved to be a failure, and in 1943 a new project was initiated named Me 209. This project, besides having the same name, had nothing to do with the original Me 209 record holding aircraft. The first prototype of this new design was designated Me 209V5 in order to avoid confusion with the previous Me 209 aircraft design. It used many components of the already existing Bf 109G and had a fairly sound design. The few prototypes built would receive the designation Me 209A (sometimes referred to as Me 209II) designation. Despite their improved performance over the Bf 109G, the Luftwaffe opted for the Fw 190D instead, which proved to be a better use of the Junkers Jumo 213 engine.

The Me 209A, besides the name, had nothing in common with the first Me 209 aircraft. Source: www.luftwaffephotos.com

Production

Production of the Me 209 was carried out by Messerschmitt at Ausburg. The RLM ordered three prototypes to be built which were completed by 1938.  The fourth prototype was Messerschmitt’s own project which ultimately proved to be a failure.

Production Versions

  • Me 209 V1 –  First prototype was successfully managed to break the world speed record.
  • Me 209 V2 –  Lost in a landing accident
  • Me 209 V3 –  Third prototype that did see limited use
  • Me 209 V4 –  This prototype was intended to serve as a base for a new fighter, but due to its poor performance, this project was canceled.

Conclusion

Despite its problematic design, it managed to reach an extraordinary speed of 755 km/h and thus set a record that would take decades to be beaten. For this alone, the Me 209 held a great place in aviation development and achievement history. That same could not be said for its attempt to be modified and used as a fighter aircraft. Despite a series of modifications and improvements, it was simply unfit to be used in this role.

Me 209V1  Specifications

Wingspans 7.8 m / 25  ft 6  in
Length 7.3 m / 23  ft 8 in
Wing Area 10.6 m² / 115 ft²
Engine (early rating) 1,800 hp DB 601ARJ
Maximum Takeoff Weight 2,512 kg / 5,545 lbs
Maximum Speed 755 km/h / 470 mph
Flight duration 35 minutes
Crew 1 pilot
Armament
  • None

 

Me 209V4  Specifications

Wingspans 10 m / 32  ft 11  in
Length 7.24  m / 23  ft 9 in
Wing Area 11.14 m² /  120  ft²
Engine 1,100 hp DB 601A
Maximum Takeoff Weight 2,800 kg / 6.174 lbs
Maximum Speed 600km/h / 373 mph
Cruising speed 500 km/h / 311 mph
Climb rate per minute 1,125 m / 3,690 ft
Maximum Service Ceiling 11,000 m / 36.080 ft
Crew 1 pilot
Armament
  • One 2 cm cannon and two 7.92 mm MG17  machine guns with additional weapons that were to be installed in the wing

Gallery

Me 209 v1
Me 209 v1
Me 209 v4
Me 209 v4

Credits

  • Article written by Marko P.
  • Edited by  Henry H. and Ed
  • Ported by Henry H.
  • Illustrated by Ed

Source:

  • D. Nesić  (2008)  Naoružanje Drugog Svetsko Rata-Nemačka. Beograd.
  • R. Jackson (2015) Messerschmitt Bf 109 A-D series, Osprey Publishing
  • J. R. Smith and A. L. Kay (1972) German Aircraft of the WW2, Putham
  • D. Myhra (2000) Messerschmitt Me 209V1, Schiffer Military History
  • M. Griehl () X-planes German Luftwaffe prototypes 1930-1940, Frontline Book
  • E. M. Dyer (2009) Japanese Secret Projects Experimental Aircraft of the IJA and IJN 1939-1945, Midland

 

Messerschmitt Me 163C

Nazi flag Nazi Germany (1944)

Rocket-Powered Interceptor Fighter: Reached Prototyping Stage

A diagram of the improved rocket interceptor. (Nevingtonwarmuseum)

When the Me 163B entered service, it was a unique aircraft by virtue of its rocket engine. It was used as a short range interceptor for German air defense, and while it could achieve extremely high speeds, its overall design left much to be desired. These faults included a highly restrictive view from the cockpit, a lack of retractable landing gear, and limited operational endurance. In order to address some of these issues,  Messerschmitt engineers developed the Me 163C.

 

History 

While the Me 163B Komet proved to be a remarkable design, it was quite dangerous to fly  and there was plenty of room for improvement.  In order to make the whole aircraft as cheap as possible, some limitations had been introduced. To save weight, the aircraft had rather small dimensions which, in turn, limited the fuel load that could be stored inside. This led to a limited powered flight time of fewer than 8 minutes. In combat operations, this proved to be insufficient, but there was little that the German engineers could do to improve this. Adding internal or external auxiliary fuel tanks was not possible given the design restrictions.

Me 163B rocket interceptor, accepted into limited service. (militaryimages.net)

The position and layout of the cockpit also offered a number of issues. Most importantly, it provided the pilot with a limited field of view behind his aircraft. Another issue was the lack of retractable landing gear. The Me 163 was instead forced to use a two-wheeled detachable dolly. This was intentionally done in order to reduce weight.

Once the aircraft was in the air, the dolly was jettisoned. There were accidents regarding this system when, for example, the dolly refused to be detached from the aircraft, or even worse, when it bounced off the ground and hit the aircraft from below. On landing, the Me 163 was to use a simple retractable landing skid, placed beneath the fuselage. After landing, the aircraft was immobile and became an easy target for enemy fighters. For this reason, a normal retracting landing gear unit was desirable, but once again for the same reason as the fuel load, this could not be implemented.

To redress the previously mentioned issues, engineers at Messerschmitt began working on an improved version, the Me 163C. It incorporated a longer fuselage, an improved cockpit, and had an engine with two combustion chambers. The development of this version likely started in late 1944 or early 1945.

Production and service

The precise development history, and how many aircraft of this version were built, are the subject of considerable speculation. The fact that there are no photographs of it complicates the matter further. Most sources mentioned that only a few incomplete airframes were built by the Germans. In some sources, for example B. Rose’s Secret Projects Flying Wings and Tailless Aircraft, it is mentioned that three prototypes were completed and flight-tested in early 1945.  Source E. T. Maloney and U. Feist on the other hand, mentions that only a few pre-prototype airframes were built by the time the war ended in Europe. So there are two completely different accounts in the sources.

Technical characteristics

The Me 163C, like its predecessor, was designed as a high-speed, rocket-powered, swept-wing, tailless aircraft. Given its experimental nature and its late development into the war, not much is known about its precise technical characteristics. Its overall construction would probably be similar to the previous version, with its fuselage being built of metal, and possessing wooden wings. The semi-monocoque fuselage was longer and was now 7 m compared to the original 5.84 m length.

The Me 163C was to be powered by an improved Walter 109-509C or an HWK 109-509A-2 rocket engine. In the case of the first engine, it could generate a thrust of some 1.500 kg.  An auxiliary HWK 509 rocket engine would be used to provide additional endurance once the aircraft reached its cruising altitude. The maximum speed of the Me 163C was estimated at 915 km/h while the operational range was 125 km.

While the introduction of retractable landing gear was desirable, the Me 163C was not to be equipped with one, but it still received some modifications in this regard. It was to have a fully retractable tail wheel located at the bottom of the tail assembly.

The cockpit was completely redesigned. It received a fully glazed bubble-type canopy. This offered the pilot a much improved all-around view. In addition, there were provisions for pressurization equipment.

The armament used on this aircraft is not quite clear in the sources. It would have consisted of either two 2 cm MG 151 with 100 rounds of ammunition for each cannon, two 30 mm MK108 cannons with 60 rounds, or less realistically, four 30 mm MK108 cannons with 40 rounds of ammunition.

Note the redesigned canopy, auxiliary engine, and extended fuselage. (www.walterwerke.co.uk)

Cancelation of the project

While the precise development of this aircraft is unclear, most sources agree on the reasons why it was not adopted, beyond the obvious end of the war. Basically, there were two main reasons for this. First, was the lack of landing gear. The Me 163C still had to take off and land using the take-off dolly and the landing skid. This was far from perfect as the dolly, as mentioned, could potentially damage the aircraft itself after release, and the use of a sliding skid made the aircraft immobile after landing. Lastly, the auxiliary engine only extended the operational flight by an additional 1-minute, which was deemed insufficient.  It was for these reasons that  the Me 163C would not be adopted, and instead the development of the much improved Me 163D was prioritized.

Conclusion

Given its experimental nature, it’s late introduction, and the disagreement between sources, it is quite difficult to make the final decision on the general properties of this aircraft. Given that the project was canceled by the Germans, it is likely that besides a few experimental prototypes, no actual production aircraft were be assembled. Regardless it served as a stepping stone for the next version, the Me 163D, which was built, but it too would not be adopted for service due to the end of the war.

Me 163C Specifications

Wingspans 32 ft 2 in / 9.8 m
Length 23 ft 1 in / 7 m
Height 3 m / ft  in
Wing Area 220 ft² /  20.41 m²
Engine Walther HWL 509C-1 liquid fuel  rocket engine with a max thrust of 1.500 kg
Empty Weight 4,850 lbs / 2,200 kg
Maximum Takeoff Weight 11,680 lbs / 5.300 kg
Maximum Speed 570 mph / 915 km/h
Operational range 78 mil / 125 km
Engine endurance 12 minutes
Maximum Service Ceiling 40,000 ft /  12,200 m
Crew One pilot
Armament
  • Two 20 cm MG 151 (100) / Two 30 mm MK108 cannons  60
The Me 163C Rocket powered interceptor.

Credits

  • Article written by Marko P.
  • Edited by  Henry H. and Medicman11
  • Ported by Marko P.
  • Illustrations by Carpaticus

Source:

  • D. Nešić (2008)  Naoružanje Drugog Svetsko Rata-Nemcaka. Beograd.
  • E. T. Maloney and U. Feist (1968) Messerschmitt Me 163, Fallbrook
  • M. Emmerling and J. Dressel  (1992) Messerschmitt Me 163 “Komet” Vol.II, Schiffer Military History
  • J.R. Smith and A. L. Kay (1990) German AIrcraft of the Second World War, Putnam
  • W. Spate and R. P. Bateson (1971) Messerschmitt Me 163 Komet, Profile Publications
  • M. Ziegler (1990) Messerschmitt Me 163 Komet, Schiffer Publishing
  • D. SHarp (2015) Luftwaffe secret jets of the Third Reich, Mortons Media Group
  • M. Griehl (1998) Jet Planes of the Third Reich, Monogram Aviation Publication
  • B. Rose (2010) Secret Projects Flying Wings and Tailless Aircraft, Midland
  • http://www.walterwerke.co.uk/walter/me163d.htm

 

Ikarus IK-2

kingdom of yugoslavia flag Yugoslavia (1933)
Fighter – 2 Prototypes & 12 Production Aircraft Built

The IK-2 fighter aircraft. Source: www.vazduhoplovnetradicijesrbije.rs

During the early 1930’s, the Royal Yugoslav Army Air Force (RYAF) was mainly equipped with old and obsolete biplane fighters. The introduction of a new fighter was desirable, but its development was hampered by the resistance of leading military officials, and pilots who still believed in the superiority of the biplane. Once Ikarus commenced production of the new high-wing IK-2, it readily demonstrated its superiority over the biplanes of the prior generation.

History of Ikarus 

Ikarus was one of the first Yugoslavian domestic aircraft manufacturers. It was formed in October 1923 by a group of businessmen from the city of Novi Sad. The aircraft development department was led by Josip Mikl and Dimitrije Konjević. Josip Mikl had previously been involved in the development of hydroplanes for the Austro-Hungarian Empire during World War I, while Dimitrije Konjević was a former high-ranking officer in the Yugoslav Naval Air Force. The company saw success during the twenties and received a series of new orders for the production of aircraft, mostly for training. In 1927 thanks to increasing revenues, Ikarus opened a new production plant located in Zemun near the capital of Belgrade. It was heralded as a great success when it received a large production order for some 200 license-built Potez 25 aircraft in 1932.

Ikarus crest. Source: Wiki

The IK-2 Development

In early 1930, the main fighter of the RYAF was the aging Avia BH-33 biplane fighter. In the hopes of replacing it with a new domestically-developed fighter, two aircraft engineers from Ikarus, Ljubomir Ilić, and Kosta Sivčev began working on a new design. Interestingly this was a private venture and not ordered by the state, which was unusual.

While initially intended to be a low-wing fighter with retracting landing gear, due to fierce opposition from many Air Force officers and pilots who favored the old biplane design, this new concept had to be abandoned at an early stage of development. The two engineers then decided to proceed with a high-wing fighter design that was to be powered by a strong engine. A wooden mock-up was completed in 1933 which would be tested using a wind tunnel in Paris. After the first drawings and testing of the mock-up were completed, the result of this work was given to the RYAF officials in September 1933. After an analysis of all available data, a green light was given for the project, and Ikarus was instructed to build the first prototype.

At this early stage, the new fighter received the IK-L1 designation. As was common in Yugoslavia at the time, new aircraft designs usually received a designation based on the designer’s initials. In this case, I stand for  Ilić and K stands for Koča which was Kosta Sivčev nickname. The L1 represents L for Fighter (Lovac in Yugoslavian) and the number 1 indicates the first prototype. The first fully functional prototype was completed by September 1934.

The first prototype IK-L1 with its two designers Ljubomir Ilić and Kosta Sivčev next to it. Source: www.vazduhoplovnetradicijesrbije.rs

Testing the First Prototype

While the IK-L1 prototype was scheduled to be flight tested shortly after the first prototype was fully completed in September 1934, due to numerous delays it wasn’t conducted until April 1935. Unfortunately for the Ikarus and its design team, the first prototype had a very short and abrupt service life. As it was being prepared for the first series of test flights, an upswell of opposition, mainly from Captain Leonid Bajdak and other pilots, vehemently objected to the introduction of such a radical new design, arguing that the biplanes were superior. Regardless, Bajdak was chosen to fly test the IK-L1 prototype.

The maiden flight was made on the 22nd of April, 1935 at an airfield near Belgrade in Zemun. The first day of flying was rather successful, with the prototype exhibiting generally good performance. The test the following day produced largely similar results, but upon landing, some of the wing’s fabric skin was noted as slightly loose. Regardless, it was agreed that the testing should carry on. On the 24th of April, while flying the prototype, Captain Bajdak performed a series of unplanned aerobatics. At a height of 1,000 meters, he made a sharp dive, followed by an abrupt climb. This of course caused massive stress on the wing, which led to part of it breaking off the aircraft. Bajdak lost control and had to bail out. While he survived without injury, the IK-L1 prototype crashed and was completely destroyed.

According to Captain Bajdak in his report, he wrote that the IK-L1 had good controls and was pleasant to fly. The most obvious issues were the lack of visibility, due to the high-wing design. Another of his objections was the long take-off of some 300 meters. This was a surprisingly fair report from a pilot who professed such serious misgivings about this new design.

Work on a New Prototype

After an analysis of the IK-L1 wreckage, it was discovered that the accident was primarily due to poor build quality. As Captain Bajdak’s report was insufficient to make a final conclusion, Ikarus officials decided to produce another prototype. This time great care was taken to ensure the overall quality of its construction. Another change made was that the aircraft was built using mostly metal construction, with the exception of the aft fuselage and tail. The second prototype was designated IK-02 and took about ten months to be built, completed in June 1936. A new test pilot was chosen, Flight Lieutenant Janko Dobnikar. The series of flight tests were carried out at the newly opened test center stationed at the Zemun airfield. Early flight tests were quite satisfactory, with the IK-02 reaching a top speed of 435 km/h.

In 1937 the IK-02 prototype was tested in a mock dogfight against the Hawker Fury, the RYAF’s then-current biplane fighter. After a series of 16 such exercises, the IK-02 easily beat the Hawker Fury in almost every category of flight performance,  speed, climb rate, and turning ability, among others. Frustrated by the success of the new fighter, Captain Bajdak and Lieutenant Dobnikar frequently got into fierce quarrels. It ended with Lieutenant Dobnikar challenging Captain Bajdak to a flight contest. The conditions of the contest were as follows: both pilots had to reach a height of 4 km over Zemun, after which they were to race a distance of 140 km from Belgrade to Novi Sad and back. The competition was meant to end in a mock dogfight between the two. Lieutenant Dobnikar IK-02 easily won the first two rounds of the race. The mock dogfight was fierce but Captain Bajdak’s Fury was constantly overtaken by the superior IK-02. In the end, he had to admit defeat and thus concede that the IK-02 had bested the biplane. Unfortunately, the IK-02 would be lost when it was hit by lightning during a flight. As the aircraft began to catch fire, the pilot bailed out. While he survived, the aircraft crashed and burned, completely destroying it.

Limited Production

Despite both prototypes being lost to separate accidents, their overall performance was deemed acceptable and a small production order was given. In November 1937 Ikarus was instructed to produce 12 IK-2 aircraft. The first six were delivered in December 1938, with the remaining aircraft arriving by February the following year. After a brief period of adjustment and training, the IK-2 was allocated to the 6th Fighter regiment stationed in Zemun. In October 1939, the IK-2 was redeployed to Zagreb and given to the 4th Fighter Regiment. Just prior to the Yugoslavian entry into World War II, the 4th Fighter Regiment would be repositioned to Bosanski Aleksandrovac close to Banja Luka. It was part of the 107th Squadron with the task of protecting the 8th Bomber Regiment, consisting of some 23 Bristol Blenheim bombers.

Despite being superior to other fighter designs that were in service with the RYAF, it too would be replaced by the later developed IK-3 fighter. Source: www.destinationsjourney.com

Technical Characteristics

The IK-2 was a high-wing, single-engine, almost all-metal fighter aircraft.  Its fuselage was constructed of a chrome-molybdenum steel tube frame which was then covered with duralumin skin. The rear section of the fuselage close to the tail unit was covered with fabric.

The semi-cantilever wings were built using the same principle as the fuselage. The difference was that the first prototype used a fabric skin. The second prototype and the production aircraft used a duralumin skin. Two larger struts were placed beneath each wing. The tail unit was of a standard design, with one horizontal and two vertical stabilizers.

Close-up view of the IK-2 wing struts construction. Source: N. Miklušev Maketar Plus

The fixed landing gear consisted of two larger wheels and a smaller tailwheel. To help during landing the front landing gear was equipped with pneumatic shock absorbers. These were also fitted with brakes. The tailwheel was steerable. Initially, the front landing wheels were covered in a protective cover, also known as ‘spats,’ which were later removed.

The cockpit was fully enclosed. Interestingly its sliding canopy actually slid down into the fuselage sides. Quite similar to those used on ordinary cars. Due to the high wing design, the pilot’s visibility was severely limited. To somewhat remedy this issue two small glass windows were placed on the cockpit fuselage sides to help during landing.

The IK-2 cockpit was fully enclosed, but its sliding canopy slides down into the fuselage sides. Source: N. Miklušev Maketar Plus
To help the pilot cope with the cockpit’s fairly limited visibility, two smaller glass windows were placed on the cockpit fuselage sides. Source: N. Miklušev Maketar Plus

The two IK-2 prototypes were powered by an 860 hp Hispano-Suiza V-12 engine. It was equipped with an adjustable pitch three-blade propeller. The fuel tanks were located just aft of the engine in front of the cockpit. The production aircraft was powered by an 860 hp Avia HS engine. This engine was built under license in Yugoslavia. Overall performance of the aircraft did not change much, as the engine swap was mainly done to facilitate ease of maintenance.

The IK-2’s armament consisted of two 7.7 cm Darne Mle 1930 machine guns, and one 20 mm Hispano HS-9 cannon. The machine gun’s ammunition load consisted of 250 rounds each, and 60 rounds for the cannon. The cannon fired through the center of the propeller shaft, while the two machine guns were placed on each side of the front of the fuselage. Some IK-2’s had their cannon replaced with a 7.92 Browning machine gun. But by the time of the war, all available aircraft were equipped with the 20 mm cannon.

According to D. Babac, the two Darne Mle 1930 machine guns were at some point replaced with two 7.92 Browning machine guns. In addition, this author notes that the machine guns were placed above the engine compartment and not on the sides.

In War

When the war broke out on the 6th April 1941 the 4th Fighter Regiment had only 8 fully operational aircraft ready for service. Four IK-2’s suffered from mechanical breakdowns and were undergoing repairs at Zemun and Zagreb workshops. Author Z. Rendulić mentioned that only 10 IK-2 were available.

Two IK-2 (With 31 and 34 white painted markings) from the 4th Fighter Regiment were taken at Borongaj airfield in Zagreb in 1940. Note the long groove for the machine gun located above the exhaust pipes. Source: N. Miklušev Maketar Plus

In addition, the 4th Regiment had 18 to 20 Hawker Hurricanes, making this unit among the most up-to-date in the RYAF. On the first day of the war, the IK-2 was mainly used for reconnaissance. The following day, two IK-2s tried to bring down a German reconnaissance aircraft but failed to do so. One IK-2 would be lost, possibly due to mechanical breakdown. The first proper combat engagement of the IK-2 occurred on the 9th of April when during reconnaissance, a group of some 23 Bf 109 were spotted.  While one IK-2 had to land to refuel, the second one provided a delayed action in hopes of giving the 4th Fighter Regiment enough time to muster its available fighters. Shortly after, some 5 or 6 IK-2 and 8 Mk.I Hurricanes joined the fight. The German fighters were attacking in well-coordinated groups, protecting each other, while the Yugoslav fighters entered the battle in a somewhat disorganized manner. After a fierce skirmish that lasted some 10 minutes, the Germans broke off and retreated back to their base of operations in Austria. The Germans lost two aircraft, while the Yugoslavians lost three, one IK-2 and two Hurricanes.  In the next few days, engagements with the enemy were rare, but the IK-2 managed to shoot down one Ju 88, in addition to two other Luftwaffe aircraft.

The 4th Regiment would meet its fate on the 14th of April when the pilots decided to destroy their remaining aircraft in order to prevent them from falling into enemy hands. Despite their attempts, the Germans managed to capture one slightly damaged IK-2 belonging to the 4th Fighter Regiment. Four additional aircraft were acquired when the repair workshops in Zagreb and Belgrade were captured.  Some internet sources noted that up to 9 aircraft were captured by the Germans, but this seems highly unlikely and that the number of 5 is probably correct.

While a number of IK-2 were lost due to mechanical failures, the majority would be destroyed by their own crews to prevent them from being captured by the Germans. Source: www.destinationsjourney.com

In NDH Service 

Following the defeat of Yugoslavia, the Independent State of Croatia, a German puppet state was created. In June 1941 a request was made to the Germans to provide over 50 captured Yugoslavian aircraft including the IK-2, in an attempt to create a Croatian Air Force. The Germans were more than willing to give the most obsolete aircraft including four IK-2. The fate of the fifth aircraft is not clear. It may have been cannibalized for spare parts, or even sent to Germany for evaluation, but due to a lack of precise sources, we can not be sure. The Croatian Air Force regularly had problems acquiring spare parts for the Yugoslavian aircraft, as these were either destroyed, sabotaged, or commandeered by the Germans. Surprisingly the IK-2 remained in service for a few years until 1944 when they were finally withdrawn from service. They were rarely used by the Croats who often complained about its poor visibility.  Sadly no IK-2 survived the war, with all likely being scrapped.

Production Versions

  • IK-L1 –  First prototype aircraft that was lost in an accident only a few days after initial trials were conducted
  • IK-02 – The second more successful prototype
  • IK-2 – Production version

Operators

  • Kingdom of Yugoslavia – Eight were used during the April War.
  • Independent State of Croatia NDH – Used four aircraft supplied by the Germans, their service was limited.

Conclusion 

The Ikarus IK-2 was one of the earliest Yugoslavian attempts to develop the first proper fighter aircraft and was intended to replace the aging biplanes then in service with the Yugoslavian Royal Air Force.  While it proved to possess superior performance to biplane fighters, it too was quickly made obsolete by the introduction of new low-wing fighter aircraft. Regardless, the IK-2 was a sound design, which proved that the Yugoslav aviation industry, despite its small size, was capable of producing a viable mono-wing fighter aircraft.

The Ikarus’ powerful engine and impressive armament paved the way for Yugoslavia’s later advanced monoplane, the IK-3. Its performance in key areas gave it an advantage over the Hawker Fury. The IK-2 saw combat against Germany’s advances in the early 1940s before it was ultimately superseded by more advanced aircraft.

IK-2 Specifications

Wingspans 11.4 m / 37 ft 4 in
Length 7.88 m / 25 ft 8 in
Height 3.84  m / 12 ft 6 in
Wing Area 18  m² / 59 ft²
Engine One 860 hp Avia HS12YCrs
Empty Weight 1.500 kg / 3.300 lbs
Maximum Takeoff Weight 1.875 kg / 4.130 lbs
Climb Rate to 5 km In 5 minute 25 seconds
Maximum Speed 450 km/h / 280 mph
Cruising speed 250 km/h / 155 mph
Range 700 km/ miles
Maximum Service Ceiling 12,000 m / 39.370 ft
Crew 1 pilot
Armament
  • Two 7.7 mm machine guns and one 2 cm cannon
Yugoslav IK-2 107 Eskadrila, 34 Grupa, 4 Lovački Puk No.2104
Yugoslav IK-2 107 Eskadrila, 34 Grupa, 4 Lovački Puk No.2108
IK-2 in NDH service

Credits

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

Sources

  • T. Likos and D. Čanak (1998) The Croatian Air Force In The Second World War, Nacionalna i Sveučilišna Knjižnica Zagreb
  • V. V. Mikić (2000) Zrakoplovstvo nezavisne države Hrvatske 1941-1945, Target Beograd
  • Č. Janić i O. Petrović (2011) Kratka istorija vazduhoplovstva u Srbiji, Aero Komunikacije
  • D.Babac Elitni vidovi Jugoslovenske vojske u Aprilskom ratu.
  • Z. Rendulić (2014) Lovačka Avijacija 1914-1945, Teovid
  • B. Dimitrijević, M. Micevski and P.  Miladinović (2016) Kraljevstvo Vayduhoplovstvo 1912-1945
  • N. Miklušev (2013) Maketar Plus, IMPS Srbija
  • http://www.vazduhoplovnetradicijesrbije.rs/index.php/istorija/565-ikarus-ik-2