Originally Posted by
Giant Bird
I read that ETOPS on the RR powered 787 has been reduced to 60 minutes. I was surprised when I flew from SCL to MEL 10 days ago that it was a RR powered 787. I spoke to the pilot as to how come they were operating a route which required ETOPS 280 with the RR engines. He said that it was ok as the operation hours on these engines were lower that any of the engines which had to be shutdown by ANA or ANZ. LATAM were pulling the aircraft out of service when the operating hours got closer to the historical shut-down hours. This made me very nervous. My view is that defective engine design is defective, unreliable is unreliable, to operate these engines at ETOPS 330 in my view is against ETOPS principles even if it is within the regulations. There are so many factors that you cannot predict exactly as to after how many hours the defect will cause a failure. Just like in QF32 where RR gambled that their known oil pump defect would not fail early and lost the bet. Because the QF A380's were being used differently to the SQ and other A380's and therefore the engine failed earlier. They cannot be 100% sure that there will not be some previously unknown factor that will be different on the LATAM 787's which will mean they will fail earlier than the ANA and ANZ. I do not want to be 280 minutes from the nearest airport when one engine has to be shutdown and the other has the same design defect. Lucky it was a daytime flight and I told my wife that we needed to make sure one of us was always awake and if anything unusual seemed to be happening to wake me immediately if I was asleep.
Are you nervous in all forms of travel or just where aviation is concerned? Do you make sure one of you stays awake when driving down the motorway, you know, just in case? What exactly did you think you were going to do if something 'unusual happened'?
The QF32 incident was not a pump fault.
From wiki
The investigation by the
Australian Transport Safety Bureau (ATSB) indicated that "
fatigue cracking" in a stub pipe within the engine resulted in oil leakage followed by an oil fire in the engine.
[30] The fire led to the release of the Intermediate Pressure Turbine (IPT) disc. It also said the issue is specific to the Trent 900.
[31]
It wasn't a known design defect either, it was a manufacturering fault that was later discovered on several other engines worldwide after inspections. No gambling was involved. Quality control at RR however came under scrutiny, quite rightly.
Rolls-Royce determined that the direct cause of the oil fire and resulting engine failure was a misaligned counter bore within a stub oil pipe leading to a fatigue fracture.
[32] The ATSB's preliminary investigation report confirmed Rolls-Royce's findings.
[15]
It was not a predicted failure, so the rest of your post needs to be addressed.
Predictable failures are handled by 'lifeing' the componant/engine/airframe. The lifeing element takes into account cycles as well as flying hours in addition to many other forms of condition monitoring and inspection. A factor of safety is added and worse case scenario taken into account. Thats how all aircraft are operated, You could apply your logic to every critical componant on the aircraft. But you don't.
Many componants fail in service before predicted. Trends are looked at and new life rules applied often with interim inspections. This RR case is no different jus a hell of a lot more expensive.
GE had flame out issues on their GEnX engine in the early years, its now a very reliable and popular engine. RR are not unique but people do like to kick a horse when its down don't they?