General knowledge · Inventions & discoveries

The jet engine

1937–1941

Invention — aviation

Two men arrived at the same machine independently and neither knew of the other. Frank Whittle, an RAF officer, set out the idea in a Cranwell thesis in 1928, filed a patent in January 1930 and ran his first bench engine on 12 April 1937, after the Air Ministry had shown no interest and his patent had been allowed to lapse. Hans von Ohain, working in Germany with the backing of Ernst Heinkel, got into the air first: the He 178 flew on 27 August 1939. Whittle's engine powered the Gloster E.28/39 on 15 May 1941, and the turbojet went on to remake both warfare and travel.

How to spot them

▸An RAF officer whose Air Ministry was told the idea was impractical, and whose patent lapsed for want of a £5 renewal
▸Power Jets Ltd; the Gloster E.28/39; the Gloster Meteor
▸The German rival flew first, in a Heinkel, four days before the invasion of Poland
▸Suck, squeeze, bang, blow — the Brayton cycle, running continuously rather than in strokes

Key facts

A 1928 Cranwell thesis rejected by the Air Ministry as impractical (1928)

Frank Whittle's 'Future Developments in Aircraft Design'; his 1930 patent was allowed to lapse in 1935 for want of the renewal fee

The Heinkel He 178, which flew on 27 August 1939 (1939)

Hans von Ohain's HeS 3 engine, with Erich Warsitz at the controls, days before the war began

The Gloster E.28/39, which first flew from Cranwell on 15 May 1941 (1941)

Britain's first, powered by the Whittle W.1; the airframe hangs in the Science Museum

Power Jets Ltd, formed in 1936 by an officer and two ex-RAF investors

It ran its first bench engine, the W.U., on 12 April 1937; the company was nationalised in 1944

The Messerschmitt Me 262, the first operational fighter of its type (1944)

The de Havilland Comet, grounded in 1954 after metal fatigue split its fuselage (1952–54)

The first airliner of its kind in service; the crashes led to a landmark investigation at Farnborough

Its two inventors finally met in 1978, and became friends (1978)

Whittle and von Ohain appeared together at Wright-Patterson Air Force Base in Ohio

Key ideas

Air is drawn in, compressed, mixed with fuel and burned, then expanded through a turbine that drives the compressor; the leftover thrust comes from the fast exhaust — Newton's third law made into a machine
A turbofan improves on the pure turbojet by using the turbine to drive a large fan, pushing a great mass of air slowly rather than a little air very fast, which is quieter and far more efficient at airliner speeds

Quick-fire facts

•Frank Whittle (1907–96) joined the RAF as an apprentice; his patent application was filed in January 1930 and granted in 1932
•The Air Ministry's dismissal, and his own lack of funds, meant the idea sat unfunded for most of the 1930s
•Hans von Ohain (1911–98) took a German patent in 1936 while working at the University of Göttingen, and was recruited by Ernst Heinkel
•The Gloster Meteor was the only Allied jet aircraft to see combat in the Second World War, and was used against V-1 flying bombs
•The Rolls-Royce Nene was sold to the Soviet Union in 1946; copied as the Klimov VK-1, it powered the MiG-15 in Korea
•Whittle was knighted in 1948; he and von Ohain are usually credited as co-inventors
•The Concorde used Rolls-Royce/Snecma Olympus 593 engines with afterburners, the only afterburning engines to power a commercial airliner in scheduled service
•The largest engines in service, such as the GE9X, have fan diameters of about 3.4 metres — wider than the cabin of a Boeing 737
•The turbofan bypass ratio of a modern airliner engine is around 10:1 or more; most of the thrust never goes through the combustor at all

Drill it — 10 cards

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Sources

National Air and Space Museum, Smithsonian Institution — Whittle W.1X Turbojet Engine
Duncan Campbell-Smith — Jet Man: The Making and Breaking of Frank Whittle, Genius of the Jet Revolution