How often do engines make it past TBO?

Ted DuPuis said:
I know of one aircraft engine that was assembled without a wrist pin plug. Took 500 hours for the resultant catastrophic failure.

Sixy has it right.
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That is an assembly failure, not materials failure. Even so it is an outlier even in the typical failure curve that has your risk to minimum by 500hrs. You are never without chance of catastrophic failure.
 
Henning said:
That is an assembly failure, not materials failure. Even so it is an outlier even in the typical failure curve that has your risk to minimum by 500hrs. You are never without chance of catastrophic failure.
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The crack initiation and propagation manifests in the same way. The Lycoming crank failures were mostly in the several hundred hour range.
 
Ted DuPuis said:
The crack initiation and propagation manifests in the same way. The Lycoming crank failures were mostly in the several hundred hour range.
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Again, an outlier issue that falls in the typical "good to go" range and extends the average out to the 250 hrs. BTW, what percentage of Lycoming cranks suffered that failure and why? Was it a bad production run?

My point is worrying by statistical analysis is useless. Anything can happen at any time, and if the engine survives my test runs, I go back to my normal level of concern which always is >0. I don't limit my route after that any more than I would with 800hrs on the engine. If I restrict operations for 250, or 500, or whatever hours I lose a bunch of utility. Worrying about things beyond a certain degree of concern is unproductive.
 
Henning said:
That is an assembly failure, not materials failure. Even so it is an outlier even in the typical failure curve that has your risk to minimum by 500hrs. You are never without chance of catastrophic failure.
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When you are puckered up trying to find a place to land, there is no difference.
 
Henning said:
My point is worrying by statistical analysis is useless. Anything can happen at any time, and if the engine survives my test runs, I go back to my normal level of concern which always is >0. I don't limit my route after that any more than I would with 800hrs on the engine. If I restrict operations for 250, or 500, or whatever hours I lose a bunch of utility. Worrying about things beyond a certain degree of concern is unproductive.
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This I agree with. I flew 10 hour engines over the Gulf. My point was the zone of concern isn't just the first 10 hours.
 
Ted DuPuis said:
This I agree with. I flew 10 hour engines over the Gulf. My point was the zone of concern isn't just the first 10 hours.
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But…. You had two.:)

Nothing like that damn single auto-rough as you proceed into the middle of the gulf.
 
Ted DuPuis said:
This I agree with. I flew 10 hour engines over the Gulf. My point was the zone of concern isn't just the first 10 hours.
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The zone of concern is perpetual, or at least should be, the question is only one of how long to allow that concern to alter normal operations. "Worrying" about something that you don't take action against, well, that's just kinda dumb and doesn't do anything good really, it just increases your stress.
 
Alexb2000 said:
But…. You had two.:)

Nothing like that damn single auto-rough as you proceed into the middle of the gulf.
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iFlyTwins for a reason. ;)
 
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