In a preliminary investigation report released today, the ATSB outlines safety actions that have already been taken in response to an uncontained engine failure on board a Qantas A380 aircraft over Batam Island, Indonesia on 4 November 2010.
"The investigation highlights Australian and international cooperation in the interests of aviation safety," said the ATSB's Chief Commissioner, Martin Dolan. "The ATSB is the lead investigator, but many others are involved, and their cooperation has been essential".
"We're still in the early stages of investigation," Mr Dolan added, "but significant action has already been taken to minimise the risk of a recurrence".
The report identifies an overspeed-related failure in the intermediate pressure turbine disc in the aircraft's No 2 engine. Sections of the fractured disc and other engine components penetrated the aircraft's left wing and a number of other areas on the aircraft, resulting in significant structural and systems damage to the aircraft.
As a result of the investigation, the ATSB has issued a safety recommendation about potential engine problems in some Airbus A380 aircraft. The problem relates to a possible manufacturing issue with the high pressure/intermediate pressure (HP/IP) bearing structure oil pipes of some engines, which could lead to fatigue cracking, oil leakage and potential engine failure from an oil fire within the HP/IP bearing buffer space.
In response to the recommendation Rolls Royce, affected airlines and safety regulators have taken action to ensure the continued safe operation of A380 aircraft. The action involves the close inspection of affected engines and the removal from service of any engine which displays the suspected problem. In addition, the European Aviation Safety Agency has approved a modification to the engine control software to reduce the risk of an overspeed-related turbine disc failure.
In Australia, Qantas is carrying out the necessary inspections in coordination with the Civil Aviation Safety Authority.
"We stress that this is a preliminary report," Mr Dolan said. "It is intended to set out the sequence of events as we understand it so far and to highlight the safety issue we have identified. A comprehensive report will be completed within a year of the occurrence."
The report also describes the flight crew's actions in dealing with the consequences of engine failure and in landing the aircraft safely in Singapore without injury to any of the 469 crew and passengers on board.
The ATSB's preliminary factual report outlines a number of areas for further investigation. They include additional examination of the turbine disc and other engine components, onboard recorded information, damage to the aircraft and its systems, and of the response by flight, cabin and emergency services crews.
A copy of the preliminary factual report is available on the ATSB website at: AO-2010-089