Supersonic Aerospace International (SAI) has resurrected the quiet supersonic transport (QSST) after a three-year hiatus and relaunched the concept as much larger, Boeing 737-sized aircraft to operate as an all-first-class airliner.

SAI boss Michael Paulsen, the son of Gulfstream founder Allen Paulsen, is again seeking an international consortium of investors to finance a two-year, $400 million advanced study phase.

Paulsen also is recruiting an OEM to oversee the follow-on four-year development and certification phase, with an estimated price tag up to $6 billion.

"We're kind of open to whatever makes sense," Paulsen says.

Supersonic Aerospace International QSST
Supersonic Aerospace International QSST

Supersonic Aerospace International

SAI was formed shortly after the death in 2000 of Allen Paulsen, a promoter of supersonic passenger aircraft. SAI commissioned Lockheed Martin Skunk Works to develop a business jet-sized QSST, leading to what is described as a "virtually boom-less" design featuring a gull-wing, inverted V-tail and curvilinear fuselage.

But the concept stalled in 2010 amid a dispute between licence holders on more than 20 patents held by SAI over the direction of the company in the wake of the post-2007 global financial crisis.

As the market slowly recovered, SAI re-imagined the QSST as a much larger aircraft with 4,500nm (8,330km) range, 20-30 seats with 48in (122cm) pitch and catering to the niche market for all-first class airline routes.

Such a concept scales up the QSST-X to a maximum take-off weight of about 90,700kg (200,000lb), Paulsen says. It would remain capable of a cruise speed of Mach 1.6-1.8. SAI would seek to change the aluminium-lithium fuselage conceived in the initial design phase a decade ago to an all-composite structure.

SAI's concept still faces many of the same technical challenges that loomed before the QSST's involuntary hiatus began three years ago. There remains no purpose-built propulsion system for a supersonic civil transport aircraft, although Paulsen is encouraged that recent developments in subsonic turbine efficiency can be adapted to supersonic applications.

Source: Flight International