Guy Norris/LOS ANGELES
Boeing has suspended deliveries of all widebodies and the 757 until it can reach agreement with the US Federal Aviation Administration over corrective actions. The work is to modify flightdeck drip shields that were incorrectly put together at the company's Spokane site in Washington.
The 747, 757, 767 and 777 are affected by the problem. Boeing says that, although the "non-conforming" flightdeck drip shields still perform their intended function of managing and channelling condensation in the roof space above the cockpit, the current configuration fails a key FAA flammability test.
As a result, Boeing is revising the manufacturing process at Spokane to correct the problem at source, as well as developing corrective actions to modify 34 aircraft already assembled, but awaiting delivery. It is also making changes to aircraft already on the production line, as well as studying retrofit options for aircraft in service.
The company does not yet know how many in-service aircraft are affected by the problem, nor how much a modification programme would cost. It says only that the non-conformal shields have been installed in the four affected models for "a few years", and that "potentially hundreds of aircraft" could be involved. The shield, which arrives in one complete unit from Spokane, consists of a hard Kevlar shell bonded with an insulating material and a plastic sheet, which acts as a vapour barrier. The shield varies in size from a 1 x 1.6m unit in the 757 to a much larger floor-to-crown configuration in the widebody models.
Although the company expects the FAA to require some modification to the shields in aircraft awaiting delivery, it says that it does not see the "altered" flammability characteristics as being "an immediate safety concern".
It expects to gain FAA approval for its recovery plan within weeks and, playing down the potential impact of the delays, says "a few deliveries may be impacted for a few days". But Boeing says the problem is not expected to have an impact on its target of around 620 deliveries by the end of the year.
Source: Flight International
