It makes perfect sense to me that if an engine will happily run for ever at MCT or less, then it must be considerably less stressed and hence less chance of a failure than one operating at full power (10 min limit).
It makes sense, yes, but with the kind of monitoring we have now in 2016 the situation is close to being able to trade thrust for life (TBO). While your margins are still good, does the chance of an actual failure increase with increasing thrust or are you just bringing essential maintenance forward? I suppose only manufacturers/operators could tell you that definitively. Yes, I did read the linked article above but it didn’t really answer this particular question. Is it similar to scheduling the oil change every 10,000 miles in your car but actually having it at 5,000 because the computer thinks it’s time as you’ve been driving like a loony...?
In my airline we get the vast majority of our engine failures in the cruise - of course there’s much more cruising time than taking off but you’d have thought if an engine was on the way out, it’d have gone earlier when you were thrashing it to get away from the ground, rather than producing half the power or less in almost steady-state.
Excellent! Please provide a link or reference to those accident reports.
Here’s one:
Emirates 407. Although the calculations were 100T off to begin with, it was the subsequent excessive derate that did for them. Once you’ve accepted that you’re doing a reduced thrust takeoff,
long runway and all, there’s not an immediate trigger as to whether a certain level of reduction is too much as there are too many variables: mass, temperature, obstacles, etc.
And another:
MK Airlines 1602. Shorter than above but still nearly 3000m TODA.
I’m sure there are many more, some probably known only to the FOQA departments of many of the World’s airlines...