Qantas will conduct further, more detailed one-off inspections of Rolls-Royce Trent 900 engines on its A380 aircraft following the results of an additional examination of components from the engine involved in the QF32 incident on 4 November.
After discussions with the Australian Transport and Safety Bureau (ATSB) and Rolls-Royce, it was decided it was prudent to conduct further inspections of engine components, although there is no immediate risk to flight safety. This is in line with Qantas' conservative, safety first approach.
The examination took place at the Rolls-Royce facility in Derby, United Kingdom, and appears to provide a more definitive explanation for the engine failure that occurred on QF32. This resulted in a safety recommendation by the ATSB following discussions with Qantas, Rolls-Royce and the Civil Aviation Safety Authority (CASA).
The ATSB's recommendation is that these one-off inspections be conducted within two flight cycles, which provides a level of inspection over and above the current 20 cycle inspection required by the European Aviation Safety Agency (EASA). The findings apply to all relevant variants of the Rolls-Royce Trent 900 engine operated worldwide.
Qantas currently has two A380 aircraft in operational service, following the grounding of the fleet on 4 November. Both A380 aircraft will be inspected at the Qantas Jet Base in Sydney. Inspections will commence this afternoon.
Qantas will determine any further response after it has finalised the inspection regime and consulted with both regulators and the manufacturer.
Qantas does not anticipate at this stage that the inspections will have an impact on international services, however contingency arrangements will be in place, if needed.
The ATSB has described recent developments as follows:
Recent examination of components removed from the failed engine at the Rolls-Royce plc facility in Derby, United Kingdom, have identified the presence of fatigue cracking within a stub pipe that feeds oil into the High Pressure (HP) / Intermediate Pressure (IP) bearing structure. While the analysis of the engine failure is ongoing, it has been identified that the leakage of oil into the HP/IP bearing structure buffer space (and a subsequent oil fire within that area) was central to the engine failure and IP turbine disc liberation event.
Further examination of the cracked area has identified the axial misalignment of an area of counter-boring within the inner diameter of the stub pip; the misalignment having produced a localised thinning of the pipe wall on one side. The area of fatigue cracking was associated with the area of pipe wall thinning.
