Researchers plan new supersonic passenger jet

Japanese researchers are planning a new supersonic passenger jet three times the size of Concorde.

It looks like a winged javelin and would fly at twice the speed of sound, travelling twice as far as Concorde - with three times as many passengers.

Japanese researchers, who will test the NEXST in the Australian desert next month, say the boom from the supersonic jet will also be reduced to the noise level of a Boeing 747, and emissions will be cut by 75%.

For the test, an engine-less 10% scale model of the NEXST - National Experimental Supersonic Transport - will ride piggyback on a rocket, then be hurtled forwards at a speed of 1,522 mph.

After a 14 minute test flight, it will release parachutes and land.

The July 11 experiment aims to test the viability of the plane’s aerodynamic shape, which was developed through computer simulations seeking to cut the noise of supersonic flight in half.

"What we will be looking at in next month’s experiment is if our design really has the sound-reducing effect we have achieved in simulations," said National Aeronautics Laboratory spokesman Toshiharu Okuda.

Officials plan to conduct more tests with US-built engines powering the NEXST prototype over the next two years.

NAL does not expect the jet to be ready for commercial flights until 2012.

The programme has its sceptics, who point out that Japan has developed almost nothing of interest in aviation since the Second World War.

"There is a lack of experience and know-how, and in this field experience and know-how count for a lot," said Hiromu Maeda, an aeronautics professor at Kyoto University.

Maeda said the question is not so much whether Japan can create a jet that would live up to its ambitious claims.

Rather, he wondered if such a plane could ever meet the stringent safety standards required of commercial flight.

"Safety is the paramount consideration," he said. "No matter how economical your plane is, it won’t do any good unless it is absolutely safe."

But that has not prevented companies such as Boeing, which is developing its own supersonic aircraft called the Sonic Cruiser, from taking next month’s test seriously.

"We have been anticipating this event closely," said Wade Cornelius, Boeing’s vice president for global strategy.

"I think their expectations hold merit. Our Japanese partners are on the leading edge of this technology."

Asked whether success in the Australian desert could lead to a partnership, Cornelius said: "It is certainly possible. There certainly could be cooperation."

If NAL succeeds, the jet could go a long way towards pushing supersonic commercial aviation beyond the Concorde - the favoured transatlantic transport of the rich and famous.

The laboratory claims enhanced fuel efficiency and super-light design using composite materials would allow NEXST to seat 300 passengers, against Concorde’s 100, and give it a range of 7,457 miles - about twice that of the British-French jet.

It would also be 'greener', emitting 75% less nitrogen oxide thanks to a special burner.

Perhaps most importantly, NAL’s jet would be as quiet as subsonic passenger planes like the 747, allowing it to fly just about anywhere in the world.

The Concorde, with its supersonic boom, is only allowed to land in New York, London and Paris.

The laboratory declined to give a price estimate for NEXST or reveal how much of its government funding it is allocating to the project.

NAL’s total annual budget is about £120m (€185m) and it is working on two other major projects.

Japan’s Mitsubishi Heavy Industries and Nissan Motors are collaborating with NAL on NEXST.