Boeing's Mulally Talks About the 'Sonic Cruiser'

Boeing's commercial airplane chief has unveiled a more detailed model of the proposed Sonic Cruiser airliner, leading to speculation about its structure, systems and performance.

Speaking before a standing-room-only crowd at Le Bourget, Boeing Commercial Airplane Group CEO Alan Mulally said the aircraft is in its "definition phase," and airline input is being used to determine the aircraft's final form.

"How big should it be? How far should it go?-our customers will be the ones to decide," he said. Boeing has settled on a speed range for the new aircraft however, between Mach 0.95 and 0.98, just below the speed of sound.

"Generally, we know a lot about supersonic transports and the tradeoffs inherent in their design," he said. "I've worked on three supersonic programs at Boeing over the past 31 years, and have learned that fundamentally when you fly at 1.5 or two times the speed of sound, it's hard to make the costs work.

"We do see a 'sweet spot' right around both sides of the speed of sound, and this is something we'll explore with the airlines."

Mulally said the aircraft might be comparable in size to the Boeing 767, and will be capable of using existing airport facilities. If the model is any indication, the pusher-canard, twin-tail design will have two engines with large under-slung air intakes.

"In the end, this will be the shape," Mulally said, adding that the three principal engine manufacturers for transport category aircraft each have expressed interest in powering the Sonic Cruiser.

"Rolls, Pratt & Whitney and GE-all have told us that the size of the market will determine the engines for the Sonic Cruiser." Mulally also implied that the three engine makers expected some military "spillover" to make their investment worthwhile.

Asked about the impact of ATC delays on the Sonic Cruiser, Mulally said the aircraft's ability to climb 20% faster and cruise 20% higher than the current generation of airliners will keep it clear of other traffic.

Mulally said Boeing's assessment of the market has back-burnered the Blended Wing Body concept, at least for now, since the BWB "only makes sense in an aircraft larger than the 747, and we see the most growth in the 757-767 size range."

Despite this perception, Boeing plans to continue 747 production and expects to build around 500 of the type over the next ten years.