Julian Moxon/PARIS
Dassault Aviation has revealed key details of its planned supersonic business jet (SSBJ), which it says could be flying "by 2004".
The manufacturer is still hesitant about the size of the potential market for SSBJs, but Dassault Aviation vice-president Bruno Revellin Falcoz insisted when a model of the SSBJ was unveiled on 19 May that the design presents "no technical problems".
As now configured, the SSBJ would be 32.42m long, 16.95m in span and have a wing area of 130m² (1,400ft²) . Empty weight is set at 17,000kg and take-off weight around double that, at 39,000kg. Cruising speed is Mach 1.8 - considerably less than the Aerospatiale/BAe Concorde's M2 because of the need "-to keep materials and systems as simple as possible," according to Dassault.
The SSBJ would land with an angle of attack of 14°, eliminating the need for a droop nose, although pilots will probably be equipped with a "virtual display" of the runway as part of the all- weather landing system. Landing speed is put at around 270km/h (145kt). Dassault does not reveal take-off speed, although it says that the SSBJ will operate from runways of between 4,000m (12,200ft) and 5,000m.
Major concerns still surround environmental factors such as the sonic boom, emissions and take-off noise. Dassault points out that, because the eight-seat SSBJ is lighter than the Concorde - still the world's only supersonic commercial air transport - it would be expected to make "around one-sixth" of the take-off noise.
Part of the noise (and emissions) reductions would come from the use of modern General Electric F414 or Snecma M88 powerplants, using water injection in the exhaust. The higher specific thrust of these engines compared to the Olympus engines powering the Concorde would also eliminate the need for an afterburner.
The sonic boom will be around half as intense as that of Concorde, says Dassault, because the aircraft is lighter and its modern aerodynamics will minimise the pressure wave that creates the effect.
Concerns remain, however, that public tolerance to even a minor boom will prevent the SSBJ being certificated for overland use. This, in turn, could inhibit its sales prospects - particularly at the rumoured Fr500 million ($82million) asking price.
Contacts with the US Federal Aviation Administration and European Joint Aviation Authorities to discuss potential certification problems are said to be imminent, although sources indicate that there will be little advance in the USA without a US partner to help the programme towards FAA certification. Industry sources point to Lockheed Martin as one of the main hopes, since it has considerable expertise in supersonics and has already shown interest in strengthening ties with Europe.
Source: Flight International
