Installation Specs Confusing; So's The Explanation

Given the problematic nature of Boeing's relationship with its suppliers on the oft-stalled 787 Dreamliner program... perhaps it's understandable that many assumed the latest problem involving fasteners on the composite-bodied airliner was the fault of one of those contractors.

Well, you know what they say about 'assuming' anything.

According to The Seattle Times, up to 8,000 fasteners will need to be replaced on each of the first 12 Boeing 787s now in various stages of assembly at suppliers and Boeing's production line in Everett, WA. As ANN reported earlier this month, Boeing inspectors found some fasteners projecting slightly from their mounting holes, instead of lying flush with surrounding panels.

Boeing made the discovery near the end of the 57-day-long strike by workers represented by the International Association of Machinists. The news followed Boeing's announcement of yet another delay for the Dreamliner's first flight, now tentatively scheduled in early 2009.

The planemaker initially said the fasteners had been improperly installed... but as it turns out, the blame for the glitch lies instead in the hands of Boeing's own engineers, who wrote the specs on the proper way to fasten sections of the plane's carbon-fiber composite skin to its titanium structure.

Given the groundbreaking nature of the 787's construction, Boeing had to write many series of instructions on how to join various sections of the airplane together... and one set of those specifications was apparently quite confusing.

An operations manager at a Boeing supplier plant -- who asked not to be identified, out of concern for angering Boeing -- told the Times he reviewed Boeing's instructions on how to join composite materials to titanium, and found it was entirely possible to misinterpret the spec.

"If I'm struggling and a 25-year design engineer is struggling, how can you expect a mechanic to understand this?" said the manager.

Even the simplified explanation of the problem is confusing. In essence, Boeing's instructions on how to fasten the dissimilar components differ, depending on which side -- composite or titanium -- the fastener head would be on, and on whether the composite piece needed to be drilled.

Measurements on the spec governing drilled composite pieces being fastened to titanium panels -- with the fastener head on the titanium side -- were inaccurate, as well as headache-inducing. If a machinist followed the instructions, the fastener would protrude slightly in its hole... as it wasn't made clear in the spec that a bevel needed to be drilled first.

Got all that?

In any case, it's fair to say workers feel slightly vindicated by the revelation. "I don't think it should be pushed on the inexperience of the mechanics," said Joy Romero, VP of the 787 program for Vought Aircraft, which assembles aft fuselage sections for the 787 in Charleston, SC. "It's more about the clarity of the specifications and the confusion of the specifications."

Alas, it's a small victory... as quality control inspectors must now locate and replace the errant fasteners. In many cases, that includes ripping off insulation and interior panels already put in place. Teams will need to work about a week at a time to find and reinstall the fasteners in one aircraft.

FMI: www.boeing.com, www.voughtaircraft.com