NR decay. Might be very expensive. Like that Bristow S76C++ NR decay in Nigeria that the crew hushed up but which was subsequently discovered by maintenance. I think the whole power train got scrapped.
Well, hushing it up is impossible. Far to many protocols in place.
Rumour is that this S92 dropped the AC Generators offline due to the Nr decay!
If that rumor is true, ouch. Nearly every major component has become nothing but mere anchor weight. Curious as to what phase of the approach the crew were in. There have been very similar incidents over the years. Although some NR decay was noticed not to the point were the gens dropped offline.