Heinkel He 100
Heinkel's bid to build a fighter faster than the Messerschmitt Bf 109 the Luftwaffe had already chosen. First flown in January 1938, the He 100 used a tightly cowled Daimler-Benz DB 601 and evaporative cooling to reach exceptional speed, and on 30 March 1939 Hans Dieterle set the world speed record in one at 746.66 km/h. The Luftwaffe never ordered it into production. Six prototypes were sold to the Soviet Union and three pre-production aircraft to Japan; the twelve production aircraft stayed at Heinkel's works and were used to publicise an imaginary service fighter, the "He 113". No original survives; a full-scale replica is on display at the Planes of Fame Air Museum.
Why It Mattered
Ernst Heinkel built the He 100 to surpass the Messerschmitt Bf 109, the fighter the Luftwaffe had already chosen over his own He 112. On 30 March 1939 his test pilot Hans Dieterle flew a specially modified He 100 to a Fédération Aéronautique Internationale (FAI) world speed record, averaging 746.66 km/h (463.953 mph). The record stood for just under a month, until Fritz Wendel took it on 26 April 1939 in Messerschmitt's Me 209 V1 at 755.14 km/h. The He 100 was never ordered into series production and never entered operational service; its importance rests on those record flights and on the propaganda career that followed them.
Design Notes
Power came from the Daimler-Benz DB 601, the same engine as the Bf 109 and Bf 110, mounted well forward of the wings under a cowling fitted tightly around it. Everything else served the reduction of drag: the landing gear, tailwheel included, retracted completely and was enclosed in flight. The boldest step was the cooling: instead of a high-drag radiator, Heinkel fitted an evaporative, or "steam", cooling system that promised to be completely drag-free. In practice the cooling pumps failed often enough to end test flights early, and landing gear failures damaged four of the prototypes. Luftwaffe test pilots disliked the high wing loading, which produced landing speeds so great that brakes were needed almost to the end of the landing run. For the production aircraft, Heinkel abandoned the surface cooling system and fitted a larger retractable radiator.
Operational History
The first prototype flew on 22 January 1938. On 5 June 1938 Ernst Udet flew the second prototype to a new world record over a 100 km closed circuit, at 634.73 km/h (394.40 mph). Heinkel publicised the flight as a record by the "He 112U", presenting the new fighter as a version of the He 112 it still hoped to sell. A second record machine, the third prototype, was lost that September when its main gear stuck half open and its pilot bailed out. Another airframe was chosen to replace it, and on 30 March 1939 Hans Dieterle flew this machine, the eighth prototype, to the absolute world speed record. No order followed: officially, the Luftwaffe rejected the He 100 to concentrate single-seat fighter development on the Bf 109, and ministry policy placed fighter development at Messerschmitt and bomber development at Heinkel. The He 100 also competed for its rival's engine, and there was not enough DB 601 capacity to support another aircraft using it. Heinkel completed the run anyway: the six surviving prototypes were sold to the Soviet Union and passed to the TsAGI institute for study. The three pre-production aircraft were sold to the Japanese navy as pattern aircraft, but the jigs and plans for production in Japan never arrived. The remaining twelve production aircraft formed a factory defence unit at the Marienehe works, flown by factory test pilots, which appears never to have seen action. In 1940 those aircraft were photographed in entirely fictitious markings and publicised as a new fighter, the "He 113", supposedly in large-scale service. The He 113 was entirely imaginary, yet it appeared in many Allied reports, described as having entered production.
Afterlife
No original He 100 airframe is known to exist. Even the drawings are gone: every He 100 blueprint was destroyed in a bombing raid, one reason so little detailed information about its systems survives. The tenth prototype, given the record machine's racing wings and canopy, was displayed in the German Museum in Munich as the record-setting "He 112U", and was itself destroyed in a bombing attack. What can be seen today is a full-scale mock-up of the production model, built by George Lucas of Nunda, New York, and displayed at the Planes of Fame Air Museum in Chino, California. The paper trail is still untidy: postwar references gave the aircraft B, C and D variants, but Heinkel's own documents support only the A-0 pre-production designation, and those variant names are postwar inventions.