S41
I can't answer your question , but
I seem to recall being told that this was what happened with the C-17, and was the reason/excuse for 99 Sqn crews to wear US flying suits.
The reason for the US flight (should that be flight?) suits was because we were renting the aircraft. Under the contract they had to be operated in the same way as any USAF ac and that included flying suits and head sets. Not sure what the excuse is now though - maybe we really don't want to lift that stone!!