Dassault's plans for developing a supersonic business jet with a top speed of Mach 1.8 are proceeding at a pace and details of outline design and a possible cost will be given in May.

Bruno Revellin-Falcoz, the French manufacturer's senior executive vice-president, says the company is taking the project seriously and has been running wind-tunnel tests to prove engineering theories that the aircraft will be viable.

Other manufacturers at the show had already scorned suggestions that the Supersonic Falcon - announced at NBAA in November - would proceed further than the drawing board.


At press conferences earlier in the week John Lawson, president, sales, of Bombardier Business Aircraft said that the two ultra-range business jets Global Express and the rival Gulfstream GV were at the top end of corporate buyers' budgets with aircraft costing around $35 million.

"The development costs would be so high and the cost of the aircraft so high that it sounds unlikely," Lawson says.

Cost is also the issue as far as Gulfstream is concerned. The Savannah, Georgia-based firm had worked on a similar project with Russia's Sukhoi but scrapped the project three years ago.

"Technically there is nothing stopping the development of such a jet, but given the aerodynamic problems that start taking place at around Mach 0.92 the costs of such a project is not economically viable," Moss says.

But Revellin-Falcoz is unfazed by the comments.


"The project began because our customers asked us to look at it. We had been working for several years on some concepts but the some customers said they wanted supersonic transport rather than long-haul.

"Gulfstream GV and Global Express can fly a long way but with small cabins and only two engines. I would not feel comfortable with that."

Revellin-Falcoz outlines Dassault's plans for the new jet which he says could fly at a remarkable Mach 1.8 with a three-engine configuration. "This will give us a range of about 7,200km (4,500nm) in three to four hours," he says.

Dassault engineers are wrestling with the perceived problems of supersonic aircraft - cost and environment and the more common business-aircraft manufacturer worries about comfort and convenience.

The aircraft will require a lot of fuel (more than 20 tonnes of an aircraft which will have a 40 tonne maximum take-off weight.

"We will overcome this by stretching the fuselage to incorporate the additional fuel. There will be no space in the wings for fuel but we are confident there will be no CG movement, unlike Concorde where a flight engineer is constantly involved in fuel management."

The cabin will be relatively small "but bigger than the Falcon 50," says Revellin-Falcoz.

The speed and range requirements were determined by an optimisation study. "If we go slower, say Mach 1.4, that is not such a big difference. If we go faster it will cost more."

But for Dassault, coping with supersonic aircraft is not a problem.

"Remember we were flying at Mach 2 in the Mirage 4 back in the 1960s," says Revillon-Falcoz. "We used to have the Concorde pilots flying to understand what happens at supersonic speeds."


The environmental problems such as noise are key.

"We believe that the sonic boom with a light aircraft will be much less and we will need to look at how much supersonic flying we would be able to do over land - but these issues are for much later."

Dassault chairman Serge Dassault is said to be impressed and interested by the proposals which will be given in full detail at the Falcon Operations Update conference in Nice in May.

"We do not expect to build thousands of these aircraft but we want to talk to our customers to see if they will pay to amortise the development costs."

Source: Flight Daily News