Boeing is studying a transonic airliner and an all-new conventional widebody jet in addition to the recently revealed high Mach Sonic Cruiser, Flight International has learned. The airframer has tasked engine manufacturers with parallel studies of powerplant options for the three new concepts.

The studies have emerged from the umbrella "20XX" project. This was formed five years ago within the product development group to evaluate advanced configurations, and improved manufacturing, design and systems technology.

It is understood that the three studies include a new 200-250-seat conventional design; a high-subsonic Mach 0.95-0.98 transport along the lines of the Sonic Cruiser; and a transonic transport aimed at a Mach 1.2 cruise speed.

"We have said we are looking at a broad range of new technologies under 20XX, and we are also looking at a different range of aircraft," acknowledges Boeing. "We are continuing to examine the range of possibilities, but the Sonic Cruiser is the aircraft we are talking to customers about."

Boeing has asked General Electric, Pratt & Whitney and Rolls-Royce to conduct parallel studies of three powerplant solutions. These include improved developments of the GE90, PW4098 and Trent engines employed on the Boeing 777, an all-new turbofan and an advanced technology transonic application.

"We're looking at several engine concepts," says Bob Leduc, P&W executive vice president. "One concept is a derivative using the PW4098 core, but it is one of three options. There is an advanced turbofan, which would be a brand new centreline engine. There is a third concept we are also pursuing that we think is novel and may have an application on a higher Mach number aircraft."

Of the three aircraft concepts, the transonic airliner is the most surprising. Although Boeing dropped its supersonic airliner studies in 1999 after NASA decided to abandon its High Speed Research project, the company pursued a Quiet Supersonic Platform (QSP) requirement issued last year by the US Defence Advanced Research Projects Agency.

The QSP is aimed at developing a low or no-boom supersonic capability using breakthrough technologies and unconventional design approaches. Phase one QSP contracts were awarded to Boeing, Northrop Grumman and Gulfstream, the latter also working with Lockheed Martin Skunk Works on a follow-up to earlier joint supersonic business jet studies.

The inclusion of a study aircraft capable of transonic speeds is believed to follow recent configuration and design breakthroughs. Boeing is also working on a supersonic business jet. However, former Boeing Commercial Airplanes vice president for business strategy and development Mike Bair says: "In general, once you go faster than Mach 1 plus, the fuel burn penalty is enormous. We have the sonic boom issue and we still haven't figured that out."

Virgin Atlantic says it is talking with Boeing to become a launch customer for the Sonic Cruiser, in a move widely seen as a publicity stunt by the UK airline at such an early stage of Boeing's concept studies. Virgin chairman Richard Branson says the airline expects to order up to six aircraft, which he believes will "change the way the world flies".

Source: Flight International