Hairline cracks detected in wing components of the A380 superjumbo, the world’s largest airliner, appear to have been caused during construction at the Airbus’s Broughton factory in North Wales.
After carrying out an investigation Airbus, which designs and part builds the wings for all its airliners at Filton, says unexpected additional stresses imparted by the manufacturing process are responsible.
As a result, the company is in the process of changing the way A380 wings are made and has developed a fix for affected aircraft, as the European Aviation Safety Agency (EASA) prepares to instruct operators to conduct precautionary inspections.
Airbus emphasises that the cracking problem – while needing to be addressed to avoid longer-term issues – is not a safety risk in the short-to-medium term. Airbus assembles the wings at Broughton before transferring them to the giant aircraft’s final assembly line in Toulouse f.
A wing specialist on the A380 told Flightglobal magazine that Airbus investigations indicated some parts were being stressed at a point during the manufacturing process which involves drawing the wing skin over the built-up rib and spar assembly before attaching it.
In these circumstances it is possible to get unexpected standing stresses which translate into additional loading during flight, said the specialist. Airbus is understood to have already conducted verification flights to measure actual loading and found that its original design calculations are correct. “We’ve confirmed that ordinary flight loads are exactly as predicted,” the specialist said, adding that the components’ design will remain “completely unchanged”.
Airbus insists that the cracks are “nothing of concern” and will only need to be addressed over a period of years rather than urgently. It expects EASA to release an airworthiness directive instructing operators to carry out inspections – although the precise extent of these has yet to be disclosed.
“In the long term it would have to be fixed, but in the short term it’s not a problem,” the specialist told Flightglobal.
The cracks were originally discovered in the rib feet of a Qantas A380 which suffered an uncontained engine failure in November 2010, and has since been under repair in Singapore. Airbus said it is confident that the crack problems, originally only noticed as a consequence of the Qantas repair, would easily have been detected during a later heavy check even if it had not been identified during earlier routine maintenance.
