Airbus thinks it has overcome A380 structural test failure
An Airbus A380 structural failure during wing static tests in France last week do not mean Asian Aerospace 2006 visitors are in any danger when the new very-large airliner flies here today. Airbus is confident that large modifications will not be needed, although officials concede that “some slight improvements” might be required.
Rupture of the wing very near the end of static tests came after a successful demonstration of the A380’s ability to tolerate the design limit load–the maximum normally expected to occur during operations. Subsequently, testing of the first completed wingset to the computed ultimate load (the limit load plus 50 percent) progressed until the test specimen was within about three percent of the expected limit. At that point, with the test specimen deflected to the point where the tips were more than 24 feet above their normal unloaded position both wings suffered cracks simultaneously at a point between the engines.
Airworthiness approval standards set by the European Aviation Safety Agency require manufacturers to demonstrate that ultimately there is a factor of 50 percent between forces likely to be experienced in normal service and the actual load the wing will bear. Load targets are worked out using finite element loads, which in this case were sufficiently accurate to estimate the point of failure within 3 percent.
Since manufacture of the initial wingset used in the tests, Airbus has refined the design, which will be slightly different on production rigs as a result of continued development, according to the European manufacturer. One factor may have been that earlier A380 weight-saving exercises had left no margin for error in the formal static load tests.
Here at AA2006, Airbus said it was satisfied with the now-completed tests. The company is happy that on the basis of precise measurements and their correlation to computed predictions the wing has demonstrated the required performance. Officials accept that “some fine tuning” may follow analysis of test results.