Repairs have been completed on a Qantas Airways Airbus A380 that experienced an uncontained engine failure over Singapore in November 2010.

The aircraft, registration VH-OQA, will be flown back to Australia from Singapore on 21 April, the Australian flag carrier said in a statement.

This comes after 18 months of extensive repairs on the aircraft, which suffered significant damage to its airframe. The incident occurred minutes after take off on flight QF32 from Singapore to Sydney on the morning of 4 November while the aircraft was flying over the Indonesian island of Batam.

The aircraft rolled off the Airbus assembly plant in September 2008 and entered into service that same month.

Qantas-A380-engine-cowling

Australian investigators have finished collecting data for an investigation into the uncontained failure of the Rolls-Royce Trent 900 engine. The data is being analysed and a final investigation report is expected in the third quarter of 2012.

So far, the investigations identified a defect in an oil feed tube as the cause behind an oil fire, which led to the engine failure. The defect caused a section of the oil tube to thin out and crack, leading to an internal engine oil fire that weakened the intermediate pressure turbine disc. This was then separated from the turbine shaft, puncturing the engine case and wing structure.

In January, the Australian Transport Safety Bureau (ATSB) said that both Rolls-Royce and Airbus had taken several measures to improve their processes.

The engine-maker conducted several "major internal investigations" looking into the manufacture of oil pipes with reduced wall thickness, the management of concessions of manufactured components, and the failure mode, effects and criticality analysis (FMECA) of previous component failures. In its FMECA procedures, Rolls-Royce has revised it to include numerical justifications for any assumptions made.

Rolls-Royce also revised its procedures to include feature checks and risk assessment during the design and manufacture of new structures, and introduced a revised procedure to provide training to better manage the application of retrospective manufacturing concessions.

Airbus is working with airports and firefighting agencies to develop an agreed safe method for these agencies to externally shut down the manufacturer's engines when the need arises. The agreed procedure will then be incorporated into Airbus's rescue and firefighting chart and distributed to those involved.

In its report, the ATSB said that together with the UK's Air Accidents Investigation Branch and Rolls-Royce, it is still looking into "the circumstances and missed opportunities with the potential to have detected the reduced wall thickness and offset counter bore of the oil feed pipe" before, during and after the manufacturing of the IP turbine module case.

The ATSB added that checks on the airframe and systems damage has been completed and did not reveal any significant or critical safety issues.

Source: Air Transport Intelligence news