The ongoing replacement of thousands of fasteners on 787 airframes has frozen the production line, as Boeing conducts a formal assessment of the programme's schedule, including a timeline for first flight and delivery.

Although a revised 787 schedule for the start of the flight-test programme is yet to be determined, Boeing is focusing its efforts for the rest of the year on providing a clean bill of structural health to Dreamliner One, which was originally due to fly in the third quarter of 2007, but will not now take to the air until 2009.

Although Boeing declines to comment on the pace of the ongoing schedule assessment, sources familiar with the fastener replacement timeline say that the expected completion of the fix for Dreamliner One should come by the end of December.

Yet the ongoing fastener replacement is reverberating down the assembly line. Everett, Washington-based sources add that no production airframe movements are scheduled for the remainder of the year, resulting in final assembly start for Dreamliner Five, the first General Electric GEnx-powered 787, being pushed into 2009 (the first four assembled flight test 787s will be Rolls-Royce Trent 1000-powered).

In late November, ZY998, the fatigue test airframe, was painted in preparation for its extensive testing regimen. With the painting now complete, the airframe has returned to the factory to have improperly installed fasteners fixed.

To date, of the major aircraft structures, only the wings, horizontal and vertical stabilisers have arrived for Dreamliner Five at Boeing's Everett facility. The forward, centre and aft fuselage sections are being held at supplier partners to conduct fastener replacement.

Vought, which is responsible for the fabrication of the aft fuselage, says it will take about a week per airplane to fix the problem. Vought adds that only shipsets five through 11 require new fasteners because shipsets 12 and onward have yet to receive internal structure requiring fasteners.

For the centre fuselage integrated by Global Aeronautica, the fastener situation is considerably worse, requiring "about 10,000" fasteners that need to be replaced between Dreamliners Five and Six, according to one veteran engineer in Charleston.

The Seattle Times, citing sources familiar with the situation, reports that on each shipset, 2,000 fasteners will need to be replaced on the aft fuselage and 3,000 for the forward fuselage produced by Spirit AeroSystems.

Boeing announced in November that, because of the recent 57-day industrial dispute, the 787 would not fly in 2008, though the need to replace thousands of improperly installed fasteners has pushed major 787 milestones into 2009.

Source: Flight International