GUY NORRIS / LOS ANGELES
Boeing introduces cosmetic changes to twinjet after lukewarm market reception
Boeing has begun a broad-based systems definition phase for the 7E7 project, and has released details of an updated configuration featuring an aerodynamically revised nose section, blended vertical tail and new wingtips.
The definition phase is expected to culminate around August with the confirmation of both the overall 7E7 firm mission requirements, as well as the design concept itself. In particular, it will tackle the selection of materials, system options, common core architecture, airport infrastructure issues, interiors, flightdeck and commonality.
Boeing is also expected to downselect to two engine suppliers in the third quarter, although General Electric is still believed to be holding out for sole-source exclusivity. Engine requirements call for thrust ratings of between 63,000lb and 68,000lb (280-300kN), a bypass ratio of between nine and 12, an overall engine pressure ratio of 50:1 and fan diameters up to 2.92m (115in).
Finalisation of the concept will allow Boeing to seek board authority to offer the aircraft by year-end, and to seek customer commitments during 2004. Assuming launch later next year, firm configuration is expected in the second quarter of 2005, with first flight in 2007 and initial deliveries in 2008.
Boeing says the latest configuration changes have to be "aerodynamically positive or neutral", but adds that improved performance is "not really the driver behind the effort". The changes are "much more towards differentiation" and are seen as a reflection of market indifference to the rather unremarkable baseline 7E7 design. "We want to go beyond baseline to something that people will know by sight - like the way we all know a 747 when we see one," says programme senior vice-president Mike Bair.
The cosmetic changes include a more prominent nose section with conformally swept flightdeck windows in a low-drag design reminiscent of the abandoned Fairchild Dornier 728. Other changes include integrally blended winglets in place of the raked tips defined on the baseline proposal, and a "sculpted" vertical tail with a smaller area than the more conventional, narrow-chord fin 777-style tail previously outlined.
Source: Flight International
