Air breathing test plane set to break speed record

Boeing is to test a ‘hypersonic’ aircraft next month with a ten-second flight over the Pacific Ocean at speeds of up to 5,000mph.

Boeing is to test a ‘hypersonic’ aircraft next month with a ten-second flight over the Pacific Ocean at speeds of up to 5,000mph – breaking the aviation speed record by travelling 10 times faster than a typical jet.

The prototype aircraft uses ‘air breathing’ engines, known as ‘scramjets’, which take in oxygen and combine it with hydrogen to create thrust far more powerful than a conventional jet engine.

The unmanned, £120m surfboard-shaped craft, known as the Hyper-X, was designed jointly by Boeing and Nasa.

During the flight, the Hyper-X – which is only 4m long — will fly 75 miles off the California coast for 500 miles, passing over San Nicolas island, before it is lost in the Pacific ocean.

‘We would love to put it in the Smithsonian Museum afterwards,’ said a NASA spokesman, ‘but we don’t have the money to recover it from the ocean floor.’

The Hyper-X will fly more than three times as fast as Concorde. A passenger jet flying at such speeds would fly between London and New York in 40 minutes, and could circumnavigate the globe in less than four hours.

A Boeing spokesman said: ‘We are still quite a way from strapping an undercarriage on the Hyper-X, fitting it with leather seats and calling it a jumbo, but that could start to happen within 15 years.’

During the test, the Hyper-X will begin its first flight bolted beneath the wing of a B-52 bomber, which will release it at 20,000ft. The Hyper-X will then fly atop a conventional booster rocket that will take it to a speed of around 2,000mph – scramjets only work at these hypersonic speeds – when the booster rocket will be jettisoned and the jet will kick in for ten seconds. This will be long enough to accelerate the Hyper-X to its maximum speed of 5,000mph.

Scramjets work by using an oval shaped aperture at the front to draw in air at hypersonic speeds and compress it sufficiently for it to be ignited with hydrogen fuel carried onboard. Normally, to reach these hypersonic speeds a plane would need a tank of liquid oxygen, which is a heavy and expensive payload.

If next month’s trial is successful, the test will be repeated later this year with a new prototype capable of reaching 7,000mph.

The record for the fastest civilian aircraft is 1,600mph, set by the Russian Tupolov Tu-144 in 1970. But the aircraft was retired after it crashed at the Paris air show three years later.

Air-breathing engines were also a feature of the British Aerospace Hotol spaceplane project, proposed during the 1980s.

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