After nearly two months of uncertainty, Boeing is nearing the end of yet another revision to the development schedule of its troubled 787 Dreamliner programme. The uncertainty was sparked by discovery of a major structural shortcoming in the wing-body join and, more recently, wrinkles in the carbon composite skin of fuselage barrels.
Sources familiar with the planning indicate that 787's first flight is likely to be scheduled for late November/early December, with first delivery to Japan's All Nippon Airways in the fourth quarter of 2010 - half a year adrift of its most recent target and two and a half years later than the original May 2008 plan.
Boeing will say only that it plans to detail its timeline in September. But senior programme sources say that a document known as Z18 - the latest of 18 revisions to the 787 fabrication, final assembly flow and customer delivery schedule - has been examined by Boeing Commercial Airplanes chief executive Scott Carson and is expected to be reviewed shortly by Boeing boss Jim McNerney.
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Boeing's latest 787 troubles became public knowledge on 23 June when it revealed that the side of the 787's body would have to be reinforced due to delamination of the components in the upper side of the wing join. Then, earlier in August, it was revealed that also on 23 June production of new fuselage barrels was stopped at supplier Alenia Aeronautica's Grottaglie facility due to wrinkles in their skins.
Alenia has stopped winding any new barrel sections until a method is found of manufacturing the stringer edge step that prevents wrinkling the skin of the Section 46 barrel.
These issues have put the design of significant parts of the aircraft in flux and prompted an almost two-month halt in fabrication, with fewer than 30 in various states of completion.
When the work stop order was given, Alenia held 15 shipsets in Grottaglie. After deliveries in July and August to Global Aeronautica in South Carolina, that number dropped to 13, with aircraft 17-29 in process in Italy.
Boeing has a devised a patch to repair the wrinkled areas of aircraft 5-29, to be applied in situ. The patch, Boeing says, will be affixed in two locations on the Section 46 barrel, just above the frame of door number three on the port and starboard side of the aircraft. The patches, whose impact on the aerodynamics or weight of the aircraft is negligible, will be no wider than the width of the door, which is just under 127cm (50in).
Boeing says that the patch "has already been designed and is being installed at Global Aeronautica in South Carolina and will be installed at completed sections in Italy and Everett".
Boeing declines to specify how long barrel winding at Alenia can be halted before the situation affects planning for the Z18 schedule. It says, however, that "there is no reason to think that it will affect the schedule".
To avoid disruption in deliveries from Alenia to Global Aeronautica, Boeing will resequence work on the existing barrel sections now in process in the factory. Alenia will then shift resources previously allocated to winding barrels to preparing the existing shipsets for delivery.
One industry analyst believes Alenia's difficulties point to the fundamental reality of the technically ambitious programme. "These are the best companies in the aerostructures world trying to grapple with building a completely new type of aircraft," says Teal Group vice-president Richard Aboulafia.
Source: Flight International
