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Old 7th Jan 2004, 14:33
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RogerTangoFoxtrotIndigo
 
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Two 777 Engine diversions in 1 day

Its being reported that UA 777 flying FRA-IAD diverted to KEF (PW powered) and a CO 777 NRT-HOU (GE powered) diverted into Midway. At a rough count that makes 4 engine diversions, all while over water in 6-8 weeks [1 GE90 into Dublin 1 GE90 into Forteleeza, Brazil]

Are we seeing something here that withe the benefit of hindsight may proove to be significant, equipment ages, and not always at the rate the manufacturer expects.

Personally I have always though that the 2 engine failure statistics are missunderstood, even if it is predicted only once in 10 million flight hours

1) It is predicted to happen sometime
2) That statistic doesnt discount 3 tomorrow and no more for 100 years!

Added to this there is something I like to refer to as Shuttle Mathematics. Back in 1980 it was predicted that the shuttle system would fail once in 10,000 launches (or something like that) after challenger that figure was reduced to 1 in less than 100, ie you would lose another one before completion of the ISS. I think the actual stats now show a 2 in 107.

What this tells us is that stats are just numbers built on assumptions and that in real life experience can sometimes proove them to be worthless especially when there is pressure for the "right result" from on high.

Getting to the point, I doubt that 2 of the above diversions were in ETOPS sectors so will not even find there way into the IFE stats, further distorting the real world reilability stats. I will also thow the Trent 800 (un)contained failure at MEL into this catagory.

Whos keeping score? how are these stats arrived at? is there any independent non regulatory input. Are the regulators to close to the Airlines?

NO, Im not a journalist otherwise the thread would have been titled 600 passengers narrowly escape death in engine fire horror.
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