Julian Moxon/PARIS

The lack of a suitable powerplant has forced Dassault Aviation to put its supersonic business jet (SSBJ) programme on hold.

The move follows an intense effort with engine manufacturers to solve the fundamental technical problem of how to develop an engine that would meet Stage 3 noise regulations and be reliable and affordable enough for the business aviation community.

The enormous development costs associated with a new powerplant were also deemed excessive for a single application that was likely to have only a limited production run.

Dassault announced at the 1997 National Business Aviation Association convention that it was undertaking a feasibility study of the SSBJ, but it soon became clear that the propulsion issue was hindering progress.

"Most aerospace industry observers expected this decision sooner or later," says executive vice-president Charles Edelstenne. "They knew we could not launch a new programme, particularly in this pioneering category, without the assurance of having engines that meet our criteria for thrust, fuel specifics, durability and other issues."

Three possible propulsion solutions were investigated - a derivative of a military engine, which was rejected because such powerplants are not designed for sustained supersonic flight; a major redesign of an existing civil engine, which was found to be too expensive and time-consuming to develop; and a new engine, which was rejected for the same reasons.

The company claims to have solved many of the technical issues in other areas of the supersonic business jet, however. The size, overall configuration and flight control system have been decided, and discussions with potential partners have begun.

Dassault has spent about $5 million on its studies to date, and says the work has left it "neatly poised to take the leadership" of any future programme.

Meanwhile, Gulfstream is pressing ahead with its own supersonic business jet study, saying it is too early to say whether there are any similar problems in finding a suitable engine.

"The Dassault decision has no bearing on our SSBJ work and our [18-month] study contract with Lockheed Martin Skunk Works continues," says Gulfstream.

Source: Flight International