Small Fasteners Cause Big Problems for Boeing

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Boeing has sold more than 900 787 Dreamliner commercial jets without ever having flown one, but with delays stacking up like holiday traffic over O’Hare you have to wonder if all those customers aren’t feeling some buyer’s remorse. 

Just days after admitting the first 787 flight will be pushed back until next year, Boeing revealed that as many as 3 percent of the unique fasteners — basically the nuts and bolts — holding the first five Dreamliners together were incorrectly installed and must be replaced. It’s a colossal embarrassment and serious problem for the world’s second-largest aircraft manufacturer, and it almost certainly means a sixth delay for the project and a company still reeling from a labor strike that cost billions.

Boeing won’t say exactly how many fasteners must be replaced, but Jon Ostrower of FlightBlogger, who practically lives at Boeing, says 2,500 to 5,000 will need to replaced. What’s more, the problem’s been found on parts fabricated by outside suppliers, suggesting there could be untold others that must be replaced.

Boeing stresses that the problem rests with the installation of the fasteners, not the fasteners themselves, and they must be reinstalled to ensure the aircraft’s structural integrity. “It’s a matter of whether the structure will hold together properly,” Boeing spokeswoman Lori Gunter said. “In commercial airplanes, it has to be right. It can’t be ‘good enough.’ So we go back and we fix it.”

fastener_3_2Inspectors discovered the problem about two weeks ago during an inspection of the “static test” airframe, an early production airplane that undergoes stress tests. The fasteners did not fail, Boeing says, proving the structure is stronger than it needs to be, but the company said it could not ignore any potential threat to the aircraft’s structural integrity. Inspectors later found the problem on the four 787 undergoing final assembly.

Boeing won’t disclose where on the aircraft the problem fasteners are located, but The Seattle Times says they were used to join titanium components to the plane’s composite fuselage. In an interview, Boeing spokeswoman Mary Hanson said the fasteners were installed to incorrect lengths — essentially, they are either longer or shorter than specified. As a result, she said, there is a gap between the head of fastener and the airplane surface, preventing it from lying flat.

Ostrower, citing conversations with several sources at Boeing, offers a more detailed take and explains the implications of the problem. Drilling holes in the 787’s titanium components and composite skin can leave a tiny burr. The head of the fastener sits on the burr instead of lying flush, causing stress to be focused on one spot instead of distributed evenly across the surface.

Because outside suppliers are building different chunks of the 787 and then shipping them to Boeing for final assembly, they were notified by the company of the fastener issue. Guess what? Many found that they were having the same problem, and now are doing their own damage control.

This isn’t the first fastener fiasco at Boeing. In 2007, facing a big shortage, Boeing bought temporary fasteners from Home Depot and Ace Hardware so assembly work could continue while more suppliers were lined up. Not only did locating and removing the temps turn into a huge time suck for Boeing, but removing the faux fasteners caused damage to the plane.

This is the last thing Boeing needs. The company is still reeling from a 57-day machinist strike that cost some $2 billion in lost profits. The strike has delayed the first Dreamliner flight until next year, the fifth such delay the program has seen. Now that employees are returning to work, Boeing will have to lose more time training them on fastener installation procedures.

Source: Wired blog Network November 2008