A Simplified Chronology of Early Turbojet Development
1929
1930
· January. Whittle makes a successful application to patent his turbojet. (The Air Ministry are advised of this but again fail to apply secrecy.)
1931
· April. The turbojet patent is published and thereafter becomes available to all interested parties from the National Stationary Office.
· Copies of the British turbojet patent are purchased by the German Trade Commission in London and distributed amongst German aeronautical research establishments as well as aero-engine and airframe manufacturers.
1933
· Lysholm’s proposal for a turbojet at the Milo Company (date unconfirmed).
1935
· Whittle is encouraged by his friends, Williams and Tinling, to join them in a private venture to develop the jet engine.
· Dr. Herbert Wagner initiates research at the Junkers Flugzeugwerke (JFA) to assess the gas turbine for shaft or jet power. (Focussing on the use of the axial compressor.)
· At the Aeronautical Research Division (AVA) at Göttingen, Dr. Hans von Ohain conceives a unique form of gas turbine and plans to apply this to aeronautics as a jet engine.
1936
· Power Jets Ltd formed. Turbojet development begins.
· Whittle patents his proposals for turbofan (high-bypass) turbojets and the use of reheat for thrust augmentation.
· Following (and as a result of) the establishment of Power Jets, the RAE is directed to re-activate aeronautical gas turbine research (dropped in 1930) as a means to develop shaft horsepower – focussing on the axial compressor.
1937
· April. Using diesel oil, the Whittle Unit (WU) is run for the first time at Power Jets.
· September. Fuelled by Hydrogen, a sheet-metal experimental model of the Ohain unit is run for the first time at HAG.
· Herman Oestrich considering turbojet designs at Siemens (date unconfirmed)
· Lyul’ka’s proposal for a turbojet (date unconfirmed)
1938
· March (unconfirmed). The Ohain engine is first run using liquid fuel.
· Unaware of the jet project at HAG (but probably aware of the JFA project) the Air Ministry (RLM) encourages engine manufacturers to develop the turbojet. (The axial compressor is specified.)
· Bramo, BMW & (later) Daimler Benz take up turbojet research and development.
1939
· June. The Air Ministry finally recognise the potential of the turbojet and begin funding the development at Power Jets. The RAE abandons turbo-shaft research in favour of the turbojet.
· Under Anselm Franz, Junkers Motorenwerke (Jumo) assumes development of the turbojet in place of JFA. The Wagner team (led by Max Müller) migrate to HAG to continue with their project there.
· August/November. First flight of a jet powered aeroplane: The Heinkel He.178, powered by the Ohain unit achieves two six-minute flights – the first in August, the second in November.
1941
· May. The Gloster E28/39, powered by the Whittle (W1) engine, begins a series of flight trials – accumulating 25 hours of bench tests followed by ten hours of in-flight use before a check of the engine was undertaken.
· Nathan Price proposal for a turbojet at Lockheed (date unconfirmed).
· The British agree to share their turbojet technology with the Americans.
· October. The W1 and design details of the W2 arrive in the USA.
· HAG abandons further development of the Ohain unit (date unconfirmed)
1942
· March. GE testing their AI turbojet.
· October. Flight testing of the twin-jet Bell XP-59A begins.
1943
· Flight-testing their first jet fighters (Gloster Meteor & Messerschmitt 262)
· Turbojet proposal by Tanegashima and Nagano (date unconfirmed)
1944
· January. Power Jets nationalised. Subsequent Government withdrawal of all support for Whittle’s axial front-fan development (LR1) and his centrifugal W2/700 engine with aft-fan and reheat.
· July. The Meteor jet fighter becomes operational. (Deployed against the V1 pulsejet-powered flying bomb.)
· October. The Me.262 becomes operational against Allied bomber forces.
1944/45
· Rolls-Royce share further turbojet technology with the USA. (Both countries developing centrifugal and axial turbojets.)
1945
· Appropriation of German turbojet technology following the end of the war in Europe. No significant advantages discovered over existing British and American technology in this field. However, the French elect to adopt the BMW turbojet for further development and as a foundation to their aero gas turbine industry. The USSR initially adopt the Jumo 004 for further development.
1947
· Rolls-Royce sell their most advanced operational turbojets to the USSR. The technology migrates in turn to Eastern Europe and China.
*****
After the end of World War II,
turbojet technology blossomed.
During its early development,
the axial compressor had been an aerodynamic nightmare. However, by the early
1950s, the worst of the problems had been solved – initially by the use of
bleed-air valves and then by variable inlet guide vanes and variable stators.
This displaced the centrifugal from the more powerful family of turbojets. It
is now found, usually combined with the axial, in turbo-prop and turbo-shaft
applications.
With greatly improved materials and the advent of
the turbofan and multi-spool engines, the level of attainable thrust has risen
more than a hundredfold since the W1 powered the Gloster E28/39 in 1941.
When tracing the origins of present day military or
civil aero gas turbines – worldwide – it is difficult to avoid a connection
with the humble WU that heralded in the jet age with its characteristic
whistling-shriek on 12 April 1937.
Ian Whittle
October 2010