roblp,
Interesting, didn't know that. No requirement for that in the UK airline I fly for (flying the 757). We just check O2 flow and the the mask mic on the ground with the mask still stowed, before flight.
I've heard about the requirement to have at least one pilot on O2 above something like 42,000' - can't remember the details of the requirement though...
Best rgds,
B&S
