Hans von Ohain

Hans von Ohain
Hans von Ohain in the 1970s
Born	Hans Joachim Pabst von Ohain (1911-12-14)14 December 1911 Dessau, Duchy of Anhalt, German Empire
Died	13 March 1998(1998-03-13) (aged 86) Melbourne, Florida, U.S.
Education	University of Göttingen
Occupation	Engineer (jet propulsion)
Spouse	Hanny von Ohain
Children	4

Hans Joachim Pabst von Ohain (14 December 1911 – 13 March 1998) was a German physicist, engineer, and the designer of the first turbojet engine to power an aircraft.^[1] Together with Frank Whittle he has been described as the co-inventor of the turbojet engine however, the historical timelines show that von Ohain was still a university student when in January 1930, Whittle filed his first patent for a turbojet engine and Whittle successfully ran his first engine in April 1937, some 6 months before von Ohain. Additionally, prior to designing engine and filing his own patent in 1935, von Ohain had read and critiqued Whittle's patents.^{[2][3][4][5][6][7][8]} Von Ohain stated in his biography, that "My interest in jet propulsion began in the fall of 1933 when I was in my seventh semester at Göttingen University. I didn't know that many people before me had the same thought.".^[9] Unlike Whittle, von Ohain had the significant advantage of being supported by an aircraft manufacturer, Heinkel, who funded his work.

When in 1935 von Ohain designed his overall engine layout, he based it for compactness on a centrifugal impeller (centrifugal or radial compressor) and a radial inflow turbine.^[10]

Ultimately, this configuration had too many shortcomings to be put into production; however, aided by the enormous resources of the Heinkel Aircraft Company, a developed version was sufficient to power the He-178, and on 27 August 1939, von Ohain entered history as the designer of the world's first gas turbine to power an aircraft.

Von Ohain stayed with centrifugal designs, contributing his research to Heinkel's other projects, such as the combined centrifugal/axial HeS8 and 011 ^[11] but ultimately, none of his designs were put into production and other competing German designers at Junkers and BMW, following the axial design layout, saw their engines in production, although they never solved some of the basic power and durability problems. Von Ohain, nevertheless, started the world's first jet engine industry in his homeland of Germany, with many prototypes and series productions built till 1945.

Von Ohain, having entered turbojet design some time later than Whittle, began working on his first turbojet engine designs during the same period that Whittle was building his WU engine in Britain. Their turbojet designs have been said by some, to be an example of simultaneous invention.^[12] However, von Ohain explains in his biography, that in 1935, while his own patent was being prepared,(and before he had begun construction of an engine) his lawyer gave him a copy of Whittle's patent which he read and critiqued. As a result, he was forced to modify his own application, so as not to infringe on Whittle's design.^[13]

The core of Ohain's first jet engine, the Heinkel HeS 1, which he described as his "hydrogen test engine" was run "in March or early April" according to Ohain (although Ernst Heinkel's diaries record it as September 1937).^[14]

^[15] Work on the hydrogen test engine continued but the engine required modifications to cure overtemperature problems and to fit a fuel system to enable it to run self-contained on liquid fuel which was achieved in September 1937.^[16][17] With the heavy backing of Heinkel, Ohain's jet engine was the first to power an aircraft, the Heinkel He 178 aircraft in 1939, which was followed by Whittle's engine within the Gloster E.28/39 in 1941.^[18] Turbojet powered fighter aircraft from both Germany and Britain entered operational use virtually simultaneously in July, 1944, the Me 262 on July 26 and the Gloster Meteor on July 27 of 1944,^{[19][20][21][22]} so the Me 262 was the first operational fighter jet and saw flight combat with hundreds of machines, while the few dozen Meteors saw limited action.

After the war the two men met, became friends and received the Charles Stark Draper Prize for Engineering "for their independent development of the turbojet engine."^[23][24]