Sonic Cruiser Program On Track, Boeing Says
author: Sean Broderick / Aviation Daily
Boeing has resumed "very in-depth" Sonic Cruiser discussions with most of the world's major international carriers in the last month, and the company is moving toward goals of making some final design decisions later this year and an entry-into-service -- assuming the plane is ordered and launched -- in late 2008.
Following a brief loss of momentum late last year attributable to the post-Sept. 11 priority shifts by most of the industry, the Sonic Cruiser program is back up to full speed, program VP and GM Walt Gillette told reporters yesterday.
Talks with customers thus far -- the one-year anniversary of Sonic Cruiser's unveiling is next Thursday -- have helped Boeing narrow the plane's characteristics a bit, Gillette said. Airlines have expressed a preference for, and Boeing analysis has justified, a family of 200-250-seat planes with ranges of 7,500-10,400 miles (6,500-9,000 nautical miles).
Boeing hopes to have a "general view of the configuration" frozen by the end of the year, Gillette said. Locking on other key design aspects won't be done until Boeing has clear picture of what customers want, and what is technologically possible. "It's very important not to freeze any part of the airplane before it's time," he said. "We don't want to be schedule-dictated, we want to be knowledge-dictated."
Current designs have about 60% of the plane's empty weight made up of composite materials, compared with about 10% of the Boeing 777, for example. In these scenarios, composites would make up "just about everything you can see from the outside," including the fuselage, most of the wings, the stabilizers, and engine nacelles. Secondary structures like floor beams would be made of traditional material, he said.
This -- like just about everything else at the program's early stage -- could change, Gillette cautioned. Metal suppliers "have come to us and said they can offer aluminum with much better mechanical properties and better pricing," he revealed. "We want to pick materials that give the most value, so we're looking at aluminum."
Regarding performance, wind tunnel tests have shown that Boeing's computer-generated predictions were "very close" to reality, Gillette said. The plane will be "very well behaved" aerodynamically at cruise speeds of Mach .95 to .98. Another series of wind-tunnel tests is slated for later this year.
Gillette said that Boeing's goal of a twin-engine Sonic Cruiser with operating costs "like or better than" 767-class planes remains achievable. "We are working the economics so that [Sonic Cruiser] does not need a fare premium" to make economic sense for airlines, he said. "That gives the airlines a lot of flexibility," from targeting premium passengers to running charters, he added.
While many of Sonic Cruiser's advantages could be realized in today's air traffic environment, Gillette suggested that either more advanced ATC procedures or special flight-path considerations will be needed to have the plane perform as advertised closer to the ground. The plane's fast cruise speeds would be realistic today, because it will cruise at 45,000 feet and above -- higher than any subsonic airliner.
But zipping along at above-average speeds in lower, more congested and constrained airspace is another issue -- one that Boeing hopes time will take care of. "By 2008, our hope is that ATC has the inherent flexibility to let each aircraft to fly at its most optimum abilities rather than have each one fly at the least capable aircraft's abilities," he said.
If airspace and ATC capabilities are still constrained when Sonic Cruiser enters service, everyone would benefit if the Boeing machine "had its own climb and descent profile" that would get the high-performance planes out of the way faster, he suggested. "If Sonic Cruiser doesn't get this help, it will take another four to five minutes to get to its cruise altitude, which would not be a big deal."
Boeing and FAA representatives have started dialogue on Sonic Cruiser's certification, Gillette said. "We've had some degree of local level discussions as well as discussions with senior-level FAA officials," he said. "We're out to establish a very strong working relationship early on."