This concern came to light with the advent of ETOPS.At one time crews shutdown their engines for the oil press'/quantity indications.Domestiacally no problem,in the ETOPS field regarded differently due to the fact that too many shutdowns led to the LOSS of the ETOPS privelges(engines have to meet a specific total of hours per shutdown)..Ergo press' put on the crews to really have a 'Failure' prior to S/D..This lead to some paper being out out by the 'engine' people-what the 'true 'indices are etc.
Crews then ran the eng at 'Idle' thrust,and changed Alt etc
,until they were forced to S/D....Anything to avoid the egine stopped...Haven't heard of too many s/d driftdowns lately.
