50 Fun Facts About Jet Engines

Which RAF officer submitted the first patent for a turbojet engine in January 1930?

He was a 22-year-old Cranwell graduate whose thesis had sketched the idea; the Air Ministry showed little interest and development crawled.

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

The two inventors met in 1966 and became touring friends.

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

Test pilot Erich Warsitz flew it for six minutes from Rostock-Marienehe; Nazi officials Udet and Milch were unimpressed by its 598 km/h top speed.

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

Nicknamed Schwalbe (Swallow), it entered service in April 1944, three months before the RAF's first jet; Hitler had insisted it be reworked as a bomber.

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

It entered RAF service in July 1944 and was first used against German flying bombs, scoring its first two 'kills' on 4 August.

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

The Air Ministry refused to pay it for him; months later old Cranwell friends helped him set up his own company.

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

With help from British Thomson-Houston the first prototype ran on 12 April 1937; the firm was nationalised in 1944, prompting Whittle's second breakdown.

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 British handed over an engine in 1941, which General Electric copied as the J31; the plane was underpowered and only 18 prototypes and test aircraft were built.

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?

A compressor feeds a combustor, a turbine extracts power to drive the compressor, and the leftover energy exits as a jet through the nozzle.

What extra component distinguishes a turbofan from a turbojet?

The bypass air makes turbofans far more efficient at airliner speeds, which is why they dominate medium and long-haul flying.

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

Low-bypass military engines sit around 2:1 or less; the first production turbofan had a bypass ratio of just 0.3.

What was the world's first production turbofan engine?

Its bypass ratio of 0.3 is similar to the modern GE F404 fighter engine; the TF39 for the C-5 Galaxy was the first production high-bypass design.

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

The first experimental high-bypass engine, the AVCO-Lycoming PLF1A-2, ran in February 1962 with a 6:1 bypass ratio.

Which 1990s engine's 115,000 lbf of thrust is contrasted with a de Havilland Ghost's 5,000?

Reliability improved even more dramatically, from 40 in-flight shutdowns per 100,000 engine hours to fewer than one.

The General Electric GE9X was developed exclusively for which airliner?

It first ran in April 2016, uses ceramic matrix composites in the combustor and turbine, and is rated at 110,000 lbf.

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

It relies on the vehicle's forward speed to compress air in the inlet, 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?

It was the first thrust-producing supersonic-combustion vehicle with full aerodynamic control surfaces to fly.

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.

Which engine powered Concorde, one of the last major applications of a pure turbojet?

At Mach 2 the intake did 63% of the compression and the engine only 8%; Concorde and the Tu-144 were the only airliners with afterburners.

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

Its four Ghost turbojets were buried in the wing roots; three crashes within a year 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?

Stress concentrated around square cut-outs for the ADF antennas; the redesigned Comet 4 flew until 1981 and its Nimrod derivative until 2011.

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

The first gas turbine to run self-sustaining was built only in 1903 by the Norwegian engineer Aegidius Elling.

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

It would have needed compressor technology far beyond the era; A. A. Griffith's 1926 paper on turbine design made practical axial compressors possible.

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

His widow Carlota O'Neill smuggled the hidden plans to the British embassy in Madrid after her release from prison.

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

His Cs-1 engine, predicted to give 1,000 bhp, was tested at the Ganz Works in Budapest around 1940.

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

Designated 109-007 by the German air ministry, it was abandoned with its problems unsolved as the war went badly.

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

Low-bypass military turbofans such as the F119, EJ200 and AL-31 all combine mixed exhaust, an afterburner and a variable nozzle.

What was the last fighter developed with pure turbojet engines, before turbofans took over?

Fourth-generation fighters, and late third-generation ones like the F-111 and Harrier, switched to low-bypass turbofans.

Which turbofan-powered car holds the land speed record?

The all-time record for a wheeled vehicle of any kind belongs to a rocket car, but the outright land speed record is jet-powered.

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

Propfans drive open contra-rotating propellers for turboprop economy at turbofan speeds, but noise and cheap fuel killed most early projects.

Roughly what share of Concorde's air compression at Mach 2 came from its intakes, not its engines?

At Mach 3-plus the SR-71's intake did 54% and its engine only 17%, which is why intake design dominates at high speed.

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

That reliability, plus much lower fuel burn, made routine transatlantic flights by twin-engined airliners possible by the turn of the century.

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?

It was supplied under external pressure; the gasoline-burning 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?

His 1930 patent had shown a two-stage axial compressor feeding a centrifugal one, but he chose the simpler layout; 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 had at first believed von Ohain copied his patent, but became convinced the German work was independent.

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

He put himself through a training programme and special diet devised by a PT instructor and got in at the second attempt.

Up to how much shaft horsepower can industrial gas turbines derived from jet engines produce?

Many are descended from military turbojets like the Pratt & Whitney J57 and J75, and drive generators, pumps, ships and locomotives.

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

Up to 1,400 Me 262s were built with about 300 seeing combat, delivering the first jet ground attacks and air victories.

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

The flight took off from Rostock-Marienehe aerodrome, powered by von Ohain's gasoline-fuelled HeS 3.

Which aircraft industrialist backed von Ohain after seeing the promise of his design?

Heinkel had just bought the Hirth engine company and set von Ohain up there as a new division.

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

Whittle himself later concentrated on the simpler centrifugal compressor.

Roughly how many Me 262s were produced, compared with about 15 Meteors that saw WWII action?

Around 300 Me 262s entered combat; the two types entered service within three months of each other in 1944.

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

The turbofan replaced the distinctive roar of pure jet noise with this new sound.

By which decade were all large civilian aircraft jet powered?

The piston engine was left to low-cost niches such as cargo flights.