Like the cautious dipping of a toe into suspected hot liquid, UK-based HyperMach Europe tested the waters at the Paris air show by introducing a new concept programme that will either snap back in abject failure or, just maybe, might gain some traction.

SonicStar is a 20-seat Mach 3.5 business jet that will cruise at 62,000ft (19,000m), linking Paris and New York by a flight of less than 2h. Powered by a 54,700lb (245kN) S-Magjet 4000X hybrid electric/gas turbine engine being developed in the UK, it also includes mechanisms to reduce sonic boom noise, presumably to allow for overland flight. First flight could be as soon as 2021.

While easy to write off such a project as economically unrealistic and technically unfeasible, the idea of future aircraft faster than Concorde's M2.04 cruise speed is piquing interest. EADS in Paris discussed a zero-emission hypersonic transport concept that would fly at speeds up to M4, covering the Paris-to-Tokyo route in 2.5h in the 2050 timeframe.

SonicStar SSBJ
 © Hypermach

It is possible slower supersonic aircraft may appear sooner, although no programmes have moved much past the paper stage.

Aerion continues to seek a risk-sharing airframer to construct its 12-passenger M1.6 supersonic business jet that would employ two conventional Pratt & Whitney JT8-219 engines. The company continues to believe it could begin delivering the $80 million aircraft in as little as five years after securing an airframer.

Gulfstream also continues its supersonic business jet ambitions, albeit at more of a technical and political level. The company has been testing a variety of technologies that could be used for such a jet, but refuses to consider committing to the project until regulators change rules banning overland supersonic flight due to sonic boom issues.

Source: Flight International