Here in the US oxygen is required for the primary crew at over 14k cabin altitude. At 12.5-14k it's required after 30 minutes. No requirement under 12.5k.
I have flown at 12k for 1 hour and could tell that the air was much thinner and that going much higher would have started to impair.
I think that most commercial aircraft run somewhere between a 6k and 8k cabin altitude and as such a whole different set of rules apply. I don't know for sure - I'm only a private pilot.
I have flown at 12k for 1 hour and could tell that the air was much thinner and that going much higher would have started to impair.
I think that most commercial aircraft run somewhere between a 6k and 8k cabin altitude and as such a whole different set of rules apply. I don't know for sure - I'm only a private pilot.