Fasteners Added To Correct 787 Wing Supports

7/23/2009
NEWS BRIEFS
Fasteners Added To Correct 787 Wing Supports

Working to reinforce repairs to a structural flaw on the 787 Dreamliner, engineers at Boeing are adding fasteners to the wing supports, or stringers, the Seattle Times reports.

“The 17 stringers on each side don’t all require the same reinforcement, but Boeing wants one design fix for all, so whatever is the beefiest reinforcement needed will likely be done for all the stringers,” writes Dominic Gates of the Times.

High loads at the ends of the stringers – long composite rods stiffen the inside of the wing skin – have caused the jet’s composite material to delaminate at the stress points during structural testing, according to Gates.

To address the problem, mechanics must crawl inside the assembled wings to create a “U-shaped cutout” in the each stringer as part of a “thorough redesign of the plane’s wing-to-body join.”

“The reshaped stringer ends must be refastened with newly designed parts to the titanium fitting, which connects the wing stringers to similar stringers on the fuselage side of the join,” writes Gates.

A shortage of fasteners plagued production of the Dreamliner test planes at the start. Boeing announced an initial six-month delay and promptly replaced the head of its 787 program and deploying engineers into the field to help suppliers boost production. The test aircraft had to be delivered with temporary fasteners.

Months later came the news that Boeing was scrambling to replace other fasteners that had been improperly installed. That problem was traced to an engineering error made at the company’s facility in Everett, WA.

The bolts in question were used inside the fuselage to fasten titanium structure to carbon-fiber-reinforced plastic composite.

The latest delay reportedly could delay the initial 787 test flight until 2010. ©2009 GlobalFastenerNews.com

Related Stories:

• Alcoa Fastener Segment Sales Drop

Related Links:

• Boeing