‘Shark tail' shed as carriers wake up to new 787 shape
Boeing has released finalised design renditions of the 787 that show some resemblance to original "Deamliner" concept features, with the marked exception of the fin, which is essentially conventional.
Possibly the most dramatic feature of the finalised aircraft, however, is the unusually high upsweep angle, or anhedral, of the wing. Pictured (right) at standard 1g flight load conditions, "you are seeing this is what happens when you build a composite wing", says 787 senior vice-president Mike Bair. The steep angle is possible "because the composites allow us to put the same span [on the 787] as the 777, but with a smaller wingbox".
The slender 60m (197ft) span wing of the baseline 787-8 has an aspect ratio of 10 compared with 8.68 on the 777-200. Despite the narrower chord of the wingbox, and of the wing itself, Bair says the overall stiffness will be the same as a conventional aluminium structure. The short-range 787-3 derivative of the -8 will have blended winglets. Other original concept design features retained on the final design include the overall aesthetic shaping of the nose.
Although the cockpit windows do not have the depth suggested by the first renderings, the refined design has a four-panel screen and "we don't have the ‘break' at the bottom of the windshield", Bair adds.
The engine nacelles will feature noise-reduction chevrons as standard features. The larger window cutouts are adopted with the move to an all-composite fuselage. The "sharkfin" look of the empennage, and particularly the vertical tail has not been retained.
"The concept vertical tail would not work," says Bair, who believes the "aggressive look" of the final design results from the giving the job of outlining the 7E7 concept to industrial designers before letting the aerodynamicists turn it into reality. "It caused a lot of creative solutions," he adds.
Definition of the 787-9 stretch, meanwhile, continues as part of attempts to satisfy Dubai-based Emirates, which has signalled interest. "We still have some ‘trade space' left on the -9, which could still change by a seat row or two," says Bair.
In three-class configuration the study range is 259 passengers "plus 10 or 20, but even that's kind of iffy," he cautions. The entry-into-service target of the -9 stretch has also been brought forward to the end of 2010 following the order by Air Canada.
Correction: Contrary to our report last week (Flight International 26 April -2 May), Naverus is a US company based in Renton, Washington.
GUY NORRIS/LOS ANGELES
Source: Flight International
