Boeing 787 Dreamliner

Dreamliners don’t crack: Boeing 787 survives fatigue testing

A Boeing 787 Dreamliner’s carbon composite structure can take the punishment of a lifetime — three times over.

That’s the result of a five-year fatigue test of the third 787 built, which has been through a mechanized stress test mimicking more than 160,000 take-offs and landing.

This is more than 3.6 times the design life of 44,000 cycles, according to a story in Aviation Week and Space Technology.

The testing didn’t start until 2010, 18 months after initially planned, because a structural design flaw in the original area where the wing and body join together had to be corrected. But after the fix was done, the airframe stood up to the repeated flexing.

“Test results were right in line with our expectations, with no significant findings,” said Bob Whittington, Boeing 787 vice president and chief project engineer, in a statement. “We validated the robustness of the 787 design as well as our modeling, and the airplane performed so well that we extended the testing.”

Such flexing is important because aircraft aluminum is subject to fatigue fractures, and so the industry has been closely watching the new carbon composite aircraft to see how they will fare.

One the most famous examples of an aircraft failure from fatigue was Aloha Airlines Flight 243, a Boeing 737 that suffering a partial failure of the fuselage in 1988, partly due to metal fatigue.

The large machinery that did the 787 Dreamliner testing is on the far north end of the Boeing Everett site, well away from the main assembly plant, said a Boeing spokesperson.

More than 3,000 sensors collected data during the flexing. The test structure was built of more than 1 million pounds of steel.

Dreamliners don’t crack: Boeing 787 survives fatigue testing

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