Frank Whittle — Inventor of the Turbojet Engine

Whittle joined the RAF as an aircraft apprentice at age 15 after twice failing the pilot medical because of his small physique — he built up his body and reapplied under an assumed name to enter training at Cranwell. Commissioned as an officer cadet at RAF College Cranwell in 1926, he excelled as a pilot and in engineering studies despite a reputation for low flying and aerobatics that repeatedly brought him official warnings.

Location: Cranwell, England

In his graduation thesis, "Future Developments in Aircraft Design," Whittle argued that propeller-driven aircraft faced fundamental limits at high altitude and speed. The thesis, which won the college's aeronautical sciences prize, began the chain of reasoning that led him to abandon piston engines entirely within a year.

Location: Cranwell, England

Whittle filed his patent for a turbojet engine: a compressor and combustion chamber driving a turbine whose exhaust provided thrust directly, with no propeller. The Air Ministry did not judge the idea worth classifying, so Whittle retained the commercial rights. He had already been rebuffed by the Air Ministry's A.A. Griffith, who called the design impracticable with existing materials and compressor efficiencies.

Location: England

Sent to Cambridge with a mechanical sciences course in 1934, Whittle graduated with a First in 1936. Meanwhile, unable to afford the five-pound patent renewal fee and with the Air Ministry refusing to pay it, he had let the patent lapse in January 1935 — putting the turbojet concept into the public domain just as Hans von Ohain in Germany began independent work on a jet engine. Whittle later said he never saw the lapse as fatal, since his practical engineering knowledge remained his own.

Location: Cambridge, England

With ex-RAF officers Rolf Dudley-Williams and James Tinling, Whittle founded Power Jets Ltd to develop his engine, financed through the investment bank O.T. Falk and Partners after every established engineering firm — Armstrong Siddeley, British Thomson-Houston among them — had declined to back the project. Whittle continued RAF duties while running the company.

Location: England

The experimental Whittle Unit turbojet ran for the first time at the British Thomson-Houston works in Rugby. The engine, built by a small team on a shoestring budget, proved the turbojet cycle could work in practice — five years before the Air Ministry fully committed to jet flight.

Location: Rugby, England

The Gloster E.28/39 research aircraft, powered by Whittle's W.1 engine, made its first flight at RAF Cranwell — the first jet flight by a British aircraft. Whittle, barred from attending the flight himself by Air Ministry instructions, heard of it by phone. Germany's He 178 had flown nearly two years earlier with von Ohain's engine; Whittle's design had nevertheless been conceived and patented years before.

Location: Cranwell, England

With jet propulsion recognized as strategically vital, the government nationalized Power Jets, giving Whittle roughly 100,000 pounds for shares whose true significance was far greater — a settlement he regarded as inadequate. Whittle moved on to advisory roles with BOAC, later worked for Shell and Bristol Aero Engines, and emigrated to the United States in 1976, becoming a research professor at the US Naval Academy.

Location: London, England

The Rolls-Royce Welland — production development of Whittle's W.2 engine, initially built under contract by Rover before Rolls-Royce took over the program — entered service powering the Gloster Meteor, Britain's first operational jet fighter. Meteors were used against German V-1 flying bombs over England, the jet's speed advantage making it the only aircraft reliably able to catch them.

Location: England

Whittle received the Charles Stark Draper Prize — engineering's highest honor — jointly with Hans von Ohain, his German rival turned friend, for their independent development of jet propulsion. Whittle died on 8 August 1996 in Columbia, Maryland, having lived to see jet aircraft carry most of the world's passengers and its air power, all descended from the cycle he first patented at age 22.

Location: United States