Originally Posted by
HeliComparator
Well just on your bullet points, the second one is the same as the Super Puma. I don’t know when the APU is routinely started, other than at start up. For example I don’t think it is started prior to a normal landing or a low level SAR hover? Is it just started in response to some first level failure eg a generator failure. My point is that an APU is only any use if it is on, and it takes a while to start up so in the event of a sudden fairly catastrophic issue it is of no use. Of course the emerg checklist will have lots of progressive scenarios that could ultimately result in ditching after several minutes, but the real world is not always so reasonable and predictable.
Sorry, it was 35 years ago since I did my groundschool and I'd forgotten about the generators, although I do still recall 20" OEI transient is 34,900 rpm!
Some operators do start the APU before landing, but I have no clue if Bristow Norway do, or for SAR low level. It is possible, because the first time I encountered the practice was with ex-Norsk pilots that joined us, who wanted to continue the practice.