Global Fastener News

Specs Blamed for Fastener Problem on Boeing 787

Jason Sandefur

The latest fastener problem on Boeing’s Dreamliner 787 has been traced to an engineering error made at the company’s facility in Everett, WA, the Seattle Times reports.

The bolts at the center of the problem were used inside the fuselage to fasten titanium structure to carbon-fiber-reinforced plastic composite. Boeing’s instructions for fastening titanium to composite “bewildered mechanics,” reports Dominic Gates of the Times.

“Several specifications from Boeing provided ambiguous instructions and measurements that led mechanics to cut too shallowly the tops of the holes they were drilling,” Gates writes.

The specification that mechanics consult for precise instructions made proper installation impossible. “The regular spec document for installing fasteners sent the mechanic to another spec if composite plastic was being drilled,” Gates writes. “This spec then correctly sent the mechanic back to the first if the fastener head was on the titanium side, as in this case.”

“But a sub-specification that supposedly superseded the second spec contradicted the main spec with a table containing different and inaccurate measurements.”

Boeing is working to rewrite the instructions.

The fastener issue has “rippled from Everett to suppliers around the world,” writes Gates.

Since the location of all the fasteners is not certain, mechanics have to reinspect the airplane from nose to tail. One unnamed 787 mechanic described quality-control inspectors “crawling through” the first two airplanes in the assembly bay “ripping all the systems out, everything that’s in the way.”

Boeing reportedly discovered the fastener problem in the midst of the machinists’ strike. A pressurization test revealed a small gap under the heads of thousands of fasteners inside the fuselage. �2008 FastenerNews.com