A380 wing tests

Big buzz today about the news that the wings on the Airbus A380 have failed during testing, which led exaggerated headlines like “Airbus: On a wing ‘n a prayer?” in the Financial Times of India. http://www.financialexpress.com/latest_full_story.php?content_id=117851

Both Boeing and Airbus test key components (like wings) “to failure.” Basically, they put them in big monster machines and torque the suckers till they snap. I’ve seen videos and it’s pretty dramatic, and my inner 8-year-old is seriously hoping to be on hand when Boeing tests the 787.

What the test is designed to prove is that the wings will withstand 1.5 times the stress that they’ll encounter during normal operations, and that’s what’s significant about the news — the A380 wings ruptured 3.3 percent short of the target.

From The Financial Times http://msnbc.msn.com/id/11396554/

Key Quote: “Alain Garcia, Airbus executive vice president engineering, told Air Transport Intelligence, the aviation news agency, yesterday that the wing rupture had occurred at between 1.45 and 1.5 times the limit load, which was itself the maximum load likely to be experienced by the aircraft during normal service.”

And that’s the issue — since the A380 wings failed short of the target, will regulatory agencies force Airbus to go back to redesign the wing?

Airbus is saying no. Garcia told Financial Times that “essentially no modifications” would be required to production aircraft as a result of the tests.

And Airbus spokeswoman Barbara Kracht told the Associated Press http://msnbc.msn.com/id/11391971/ that while the wing may need to be tweaked, that shouldn’t be a major issue.

Key Quote: “Airbus engineers and officials from the European Aviation Safety Agency and U.S. Federal Aviation Administration will decide what if any modifications are required, she said. ‘We will need to find out from the data what is really needed, but it’s certainly not a redesign of the wing.’”

In any case, Airbus will be able to deliver the first A380s this year as planned, she said.

But that’s assuming the regulatory agencies don’t require Airbus to greatly strengthen the wing. If they do, that will send Airbus back to the digital drawing board to design and build a new wing, which means further delays for a program already running six months late. And if that beefed-up wing is heavier — as is reasonable to assume — that would change the weight calculations for the A380, and the performance.

Flight International takes a more-detailed look. http://www.flightglobal.com/Articles/2006/02/16/Navigation/177/204716/Airbus+A380+test+wing+breaks+just+below+ultimate+load.html

Key Quote: “Garcia says that the FEM calculations had already established that the A380’s wing had ‘no margin at ultimate load. We had a weight saving programme and played the game to achieve ultimate load.’ However in earlier briefings, Airbus structural engineers had stated that it planned to carry out ‘a residual strength and margin research test’ in 2006 after completing ultimate load trials.”