Originally Posted by issi noho
Baritone
You raise a point I've wondered about, trend monitoring. Running the remaining 3 at MCT for XX hrs, does this mess up the the benefits, in maintenance terms, which you gained from a trend program?
From a design engineer's standpoint, the critical airfoils in an engine come up to temperature very quickly. The 5 minute (sometimes 10 minute) TO rating is an artificial one from the metallurgist's view. The limit is really the erosion that takes place over many hundreds or thousands of hours. So, running at MCT for 10 hours won't make the accountants happy, because it might shorten the on-wing time from 10000 hours to 9990 - but it's NOT a safety issue as long as the EGT/ITT/TIT limits are observed.
And can you answer one more thing, at what point in the flight was it apparent that LHR was not an option?
Thanks
Probably when they got an estimate of destination holding time from ATC.
