48 Fun Facts About Jet Engines

Which RAF officer patented his turbojet engine design in January 1930?

Frank Whittle filed his turbojet patent on 16 January 1930, aged 22; his Cranwell thesis had sketched the idea, but the Air Ministry showed little interest.

Which German engineer began building a rival turbojet in 1935 that became the first to fly?

Hans von Ohain patented his design in 1935 and joined Heinkel in 1936; his HeS 3 engine powered the first purely turbojet flight in August 1939.

What was the world's first aircraft to fly purely on turbojet power, on 27 August 1939?

The Heinkel He 178, powered by an HeS 3B engine, made the first purely turbojet flight from Rostock-Marienehe on 27 August 1939; a later demonstration left Udet and Milch unimpressed.

What was the world's first operational jet fighter, powered by Junkers Jumo 004 engines?

The Messerschmitt Me 262 Schwalbe entered service with Erprobungskommando 262 in April 1944, months before any Allied jet; Hitler insisted it also be reworked as a fighter-bomber.

Which British jet fighter was the only Allied jet aircraft to see combat in the Second World War?

The Gloster Meteor entered RAF service with 616 Squadron in July 1944 and scored its first two kills against V-1 flying bombs on 4 August 1944.

What was Whittle's problem in January 1935 that caused his original jet engine patent to lapse?

Whittle let the patent lapse in January 1935 because he could not afford the £5 renewal fee and the Air Ministry declined to pay it; Cranwell friends helped him found a company the next year.

What was the name of the company Whittle formed with two retired RAF servicemen to build his engine?

Power Jets Ltd was formed in 1936 with retired officers Rolf Dudley-Williams and James Tinling; its WU engine first ran on 12 April 1937 and the firm was nationalised in 1944.

What was the first British aircraft to fly with a turbojet, on 15 May 1941?

It used a Power Jets engine; the Meteor that followed entered service in July 1944.

What was the first US-built jet aircraft, built around a copy of a donated British engine?

The Bell P-59 Airacomet first flew in October 1942 on General Electric I-A engines copied from a Whittle W.1X shipped from Britain in 1941; it proved too slow for combat.

Which Austrian engineer at Junkers gave the Jumo 004 its axial-flow compressor?

After the war the Allies studied captured German engines closely, and their legacy is visible in nearly every fixed-wing jet since.

What is the name of the thermodynamic process gas-turbine jet engines operate on?

Gas turbines run on the Brayton cycle: a compressor feeds a combustor, a turbine extracts power to drive the compressor, and the leftover energy exits as a jet through the nozzle.

Which component gives a high-bypass airliner engine most of its thrust?

A turbofan adds a large fan that pushes bypass air around the core; that bypass air supplies most of the thrust and makes the engine far more efficient than a turbojet at airliner speeds.

If a turbofan has a bypass ratio of 6, what does that mean?

A bypass ratio of 6 means six times more air passes around the core than through it; low-bypass military engines sit near 2:1 or less, and early turbofans were around 0.3.

What was the world's first production turbofan engine?

The Rolls-Royce Conway, in airline service from 1960 on the Boeing 707-420 and DC-8-40, was the first production turbofan; its bypass ratio was only about 0.3.

Which aircraft was the first production high-bypass turbofan, the GE TF39, designed to power?

General Electric's TF39 was designed for the Lockheed C-5 Galaxy heavy transport, which first flew in June 1968; its 8:1 bypass ratio was unprecedented for a production engine.

Which Boeing 777 engine is rated at about 115,000 lbf of thrust?

The General Electric GE90-115B, which powers the 777-300ER, is rated at about 115,000 lbf of thrust, versus roughly 5,000 lbf for the 1940s de Havilland Ghost.

The General Electric GE9X was developed exclusively for which airliner?

The GE9X was developed solely for the Boeing 777X; it first ran in April 2016, uses ceramic matrix composites in its combustor and turbine, and is rated near 110,000 lbf.

What is the simplest type of air-breathing jet engine, having no moving parts in the engine proper?

A ramjet has no moving parts in the engine proper; it relies on the vehicle's forward speed to compress intake air, so it cannot produce thrust from a standstill.

What is the defining feature of a scramjet?

Very few have flown; the X-51A Waverider cruised at Mach 5 for about 200 seconds in 2010.

What top speed did NASA's X-43A hypersonic test vehicle briefly reach on its final 2004 test flight?

On 16 November 2004 the X-43A reached about Mach 9.6, nearly 7,000 mph, the record for an air-breathing aircraft, after its scramjet burned for roughly ten seconds.

Which German weapon of the Second World War was propelled by the Argus As 109-014 pulsejet?

A pulsejet burns in pulses and can run while stationary; the buzzing note earned the V-1 its 'doodlebug' nickname.

What does an afterburner do?

Fuel consumption is typically four times that of the main engine, so it is used almost only on supersonic aircraft - Concorde and the Tu-144 included.

What was the world's first commercial jet airliner, which entered service in 1952?

The de Havilland Comet entered BOAC service in May 1952 with four Ghost turbojets buried in the wing roots; three fatal in-flight break-ups in 1953–54 grounded it and handed the market to Boeing.

What phenomenon, poorly understood at the time, was found to have caused two of the early Comet crashes?

Metal fatigue cracks grew from the corners of the Comet's square-cornered cut-outs, notably the ADF aerial windows; water-tank pressurisation tests on G-ALYU reproduced the failure in 1954.

Which Englishman was granted the first patent for a stationary gas turbine, in 1791?

John Barber's 1791 patent described a gas turbine meant to drive a carriage; the first gas turbine to run self-sustaining was built only in 1903 by Norwegian engineer Aegidius Elling.

Who filed the first patent for a gas-turbine aircraft engine, an unbuilt axial-flow turbojet, in 1921?

Maxime Guillaume's 1921 French patent described an axial-flow turbojet that was never built; the compressor efficiency it needed was far beyond the technology of the era.

Which Spanish engineer patented a jet engine in 1935, then was executed by Francoist troops as the Civil War began?

Virgilio Leret Ruiz patented his 'mototurbocompresor de reacción continua' in 1935; he was shot by rebel troops at Melilla in July 1936, and his widow Carlota O'Neill later preserved the plans.

Which Hungarian engineer designed the world's first turboprop, patenting the idea in 1929?

György Jendrassik patented his turboprop idea in 1929; his Cs-1, designed for 1,000 bhp, ran at the Ganz Works in Budapest in 1940 but never powered a flight.

What was the world's first turbofan, which ran only on a test bed in May 1943?

The Daimler-Benz DB 670, designated 109-007 by the German air ministry, ran on a test bed on 27 May 1943; its problems were never solved and it was abandoned.

What was the first production afterburning turbofan, which powered the F-111 Aardvark and F-14 Tomcat?

The Pratt & Whitney TF30 was the first production afterburning turbofan, powering the F-111 from 1967 and the original F-14A; later Tomcats switched to the GE F110.

Which Soviet interceptor exceeded Mach 2.8 on two Tumansky R-15 turbojets?

The MiG-25's two Tumansky R-15 turbojets pushed it past Mach 2.8; Viktor Belenko's 1976 defection to Japan let Western engineers examine one closely.

Which turbofan-powered car set the first supersonic land speed record in 1997?

ThrustSSC, powered by two Rolls-Royce Spey turbofans, set the land speed record of 763 mph (1,228 km/h) in the Black Rock Desert on 15 October 1997, the first supersonic record.

What is the only aircraft to have flown powered solely by propfan engines?

The Antonov An-70 transport, first flown in December 1994, is powered by four Progress D-27 propfans driving contra-rotating propellers; Western propfan testbeds like the MD-80/GE36 flew one demonstrator engine only.

Roughly what share of Concorde's thrust at Mach 2 cruise was attributed to its intakes?

Concorde's variable-ramp intakes were credited with about 63% of thrust at Mach 2, the engines 8% and the nozzles 29%; the SR-71's inlets similarly supplied over half its thrust at Mach 3.

By the late 1990s, jetliner engines had cut in-flight shutdowns from 40 per 100,000 engine hours to what?

By the late 1990s in-flight shutdowns had fallen to fewer than 1 per 100,000 engine hours, down from about 40 in the early jet age; that reliability underpinned ETOPS twin-engine transatlantic flying.

What decisive limit was pushing engineers toward jets before the Second World War?

The gas turbine, extracting power from the exhaust to drive its own compressor, was the key that made a practical jet possible.

What fuel did von Ohain's first experimental HeS 1 engine of 1937 run on?

Von Ohain's HeS 1 demonstrator of 1937 burned hydrogen fed under external pressure, which eased combustion problems; the liquid-fuelled HeS 3 that followed produced about 5 kN and flew in the He 178.

Which type of compressor did Whittle ultimately concentrate on for his engines?

Whittle concentrated on the centrifugal compressor: his 1930 patent had shown two axial stages feeding a centrifugal one, but he chose the simpler, more robust layout, while German designers went axial.

In which US state did the British turbojet pioneer Whittle die in 1996, having emigrated in 1976?

He had been a research professor at the Naval Academy in Annapolis; British Airways flew his ashes home on a 777 that bore his name.

Which award did Whittle and von Ohain share in 1991 for their work on turbojet engines?

Whittle and von Ohain shared the 1991 Charles Stark Draper Prize, the US National Academy of Engineering's top award; Whittle had first suspected von Ohain copied his patent but accepted the work was independent.

How tall was the young Whittle when he first failed the RAF apprentice medical in 1923?

At five feet tall Whittle failed the RAF apprentice medical in January 1923 on height; a PT instructor's diet and exercise programme added inches and he was accepted as an apprentice in September 1923.

What was the world's first jet bomber, also powered by the Jumo 004?

The Arado Ar 234 Blitz, powered by two Jumo 004s, became the first operational jet bomber in 1944 and flew the Luftwaffe's last reconnaissance sorties over Britain.

Who piloted the Heinkel He 178 on the world's first jet flight on 27 August 1939?

Erich Warsitz, Heinkel's chief test pilot, flew the He 178 from Rostock-Marienehe on 27 August 1939; he had also flown the rocket-powered He 176 two months earlier.

Which Korean War Soviet fighter flew on the Klimov VK-1, derived from the Rolls-Royce Nene?

The MiG-15's Klimov VK-1 descended from Rolls-Royce Nene engines Britain sold to the USSR in 1946; the fighter fought US F-86 Sabres over Korea from late 1950.

Whose 1926 paper 'An Aerodynamic Theory of Turbine Design' made practical axial compressors possible?

A. A. Griffith's 1926 paper treated compressor blades as aerofoils, making efficient axial compressors possible; his RAE axial work led to the Metrovick F.2 turbojet, which first ran in 1941.

Roughly how many Messerschmitt Me 262 jet fighters were built by the war's end?

Up to 1,400 Me 262s were built, but only around 300 reached combat units because of fuel shortages and Allied bombing; the type entered service in April 1944.

The sound from shockwaves at a turbofan's supersonic fan-blade tips at takeoff is nicknamed what?

The 'buzz saw' noise comes from shockwaves off supersonic fan-blade tips at take-off power; it replaced the raw roar of pure turbojets once high-bypass turbofans arrived.

Which was the first US-built jet airliner to enter service, in October 1958?

Pan Am's Boeing 707 began New York–Paris service on 26 October 1958, the first US-built jet airliner in service; the rival Douglas DC-8 followed in September 1959.