Australian investigators yesterday identified the source of an oil leak that caused a superjumbo engine to blow apart in mid-air last month, and said a suspected manufacturing defect in the Rolls-Royce engine was to blame. They warned airlines the potential flaw could cause engine failure.
The Australian Transport Safety Bureau (ATSB) recommended the Qantas, Singapore Airlines and Germany’s Lufthansa, the airlines that use Rolls-Royce’s massive Trent 900 engines on their A380s go back and conduct more checks now that it had pinpointed the problem area.
Earlier warnings blamed an oil leak for a fire and subsequent chain of failures that sent heavy parts flying off an engine on a Qantas A380 shortly after it took off from Singapore on Nov. 4, the most serious safety problem for the world’s largest and newest jetliner.
The ATSB, which is leading the international investigation into the Qantas breakup, added some specifics yesterday, saying a section of an oil tube that connects the high-pressure and intermediate-pressure bearing structures of the engine was the danger area.
“The problem relates to the potential for misaligned oil pipe counter-boring, which could lead to fatigue cracking, oil leakage and potential engine failure from an oil fire within the HP/IP bearing buffer space,” the ATSB said in a brief statement.
It called the problem “a potential manufacturing defect.”
Counter-boring is when you place a larger hole over a smaller hole to make room for a seal. The ATSB said a misalignment of those holes had produced a thinning of the oil pipe wall and fatigue cracks.
The ATSB recommended close inspections of all Trent 900 engines to look specifically for signs of the counterboring problem. Any engines that display such signs should be removed from service, it said.
In response to that recommendation, Rolls-Royce, affected airlines and other safety regulators were taking action to ensure the A380s involved were safe, the bureau statement said.
Qantas, which grounded its six A380s for more than three weeks after the blowout, said yesterday it would conduct one-off checks on its superjumbos. Spokesman Simon Rushton said the inspections were not expected to take long, or disrupt service.