Originally Posted by
riff_raff
Finally, there were a couple proposed requirements that seemed a bit optimistic. For example, the Class 3 failure criteria (Imminent Failure) on p.18 states "the efficiency of the gearbox may be reduced by up to 10%.". A decent new build MRGB probably has an input/output efficiency of ~96%. So a gearbox on the verge of imminent failure after the loss of lube test cycle must still demonstrate an input/output efficiency of >86%. I don't think this particular requirement is realistic.
Riff, you might find this short presentation (download) from Leonardo interesting. If I am reading it right, that quoted 96.5% seems to refer to the MGB running after loss of lubricant (LoL) though it is not clear where in the timeline of the test that was recorded. Could that possibly be after 50 minutes LoL?
Last edited by Concentric; 12th Aug 2017 at 19:37.