Background In 1935,
Hans von Ohain, a young German engineer, successfully took out a
patent on the use of the exhaust from a
gas turbine as a means of propulsion. During September 1937, von Ohain successfully demonstrated his first engine, the
Heinkel HeS 1. Accordingly, it was promptly decided to begin designing an aircraft for which a similar such engine could be installed and tested in the air. This aircraft, which would be designated
He 178, was designed around von Ohain's third engine design, the
HeS 3, which burned either
diesel fuel or
gasoline. To support the programme, the HeS 3 was test flown in a
Heinkel He 118, but only as a supplemental engine to the conventional piston engine that it retained. The He 178 was a relatively compact aircraft, featuring a primarily metal
fuselage and using a largely conventional configuration and construction. The nose accommodated the air intake for the engine, which was housed within the central fuselage. The aircraft was fitted with
tailwheel undercarriage. The main landing gear was intended to be retractable, but actually remained fixed in the "down" position throughout the flight trials. It was furnished with high-mounted wooden wings that had the characteristic
Günter brothers elliptical trailing edge planform. Photos showing a "straight wing" (straight-line-taper in the wing planform, for the
leading and trailing edges) were of the second
prototype He 178 V2, which never flew under power.
Into flight On 27 August 1939, the aircraft performed its
maiden flight, only days before Germany invaded Poland. This flight, piloted by
Erich Warsitz, lasted only six minutes and almost ended in disaster due to a misjudgement during the unpowered landing approach, but was successfully recovered. Warsitz later described his groundbreaking flight: "I moved the throttle levers gently forward. As the aircraft began to roll I was initially rather disappointed at the thrust, for she did not shoot forward as the
176 had done, but moved off slowly. By the 300-metre mark she was moving very fast. Despite several attempts I could not retract the undercarriage. It was not important, all that mattered was that she flew. The rudder and all flaps worked almost normally, the turbine howled. Now I would have to take my chances with the landing, losing altitude by
side-slipping. I restored her to the correct attitude just before touching down, made a wonderful landing and pulled up just short of the
Warnow." Heinkel had developed the turbojet engine and the testbed aircraft, the Heinkel He 178 V1, in great secrecy. Their existence was concealed even from the
Luftwaffe. On 1 November 1939, after the German victory in Poland, Heinkel arranged a demonstration of the aircraft before a group of
Nazi officials. While
Hermann Göring, the commander in chief of the Luftwaffe, was not in attendance, the demonstration was watched by
Ernst Udet and
Erhard Milch, Minister of Aircraft Production and Supply; however, they were reportedly not impressed by its performance. while its
combat endurance was limited to only ten minutes.
Legacy Heinkel was disappointed by the lack of official interest in his private-venture jet. In his autobiography, he attributes that to the failure of the leaders of the
Reichsluftfahrtministerium to understand the advantages of jet propulsion and the breakthrough that He 178 represented. Undeterred by a lack of support from external officials, Heinkel decided to embark on the development of a twin-engine jet fighter as a private venture, harnessing what had been learned from flying the He 178 prototype. This would result in the
He 280, the first prototype jet-powered
fighter aircraft. It was not derived from the He 178, however, partially as some aspects of the design had been deemed to be unsuitable for further development, such as mounting the engine within the fuselage which proved to be impractical. Unknown to Heinkel, the Reich Air Ministry had already been developing its own jet technology. In fact, in September 1939, the development of jet powered single-seat aircraft was ordered to continue despite a general order to cut back on non-core development work as to get certain aircraft types operational as soon as possible. However, the jet engines that would be developed by
Junkers and
BMW would differ considerably from those engines used by the He 178, instead favouring the
axial flow approach in place of the earlier
centrifugal design. Nevertheless, the He 178 programme was a valuable source of test data that aided subsequent development efforts considerably. The He 178 V1 airframe was placed on display at the Deutsche Luftfahrtsammlung in
Berlin, where it was destroyed in an air raid in 1943. ==Specifications==