8000' is pretty comfortable from an air pressure perspective. In practice, I'll do 9,500' or so for longer durations in an unpressurized plane in the daytime.

8000' is pretty comfortable from an air pressure perspective. In practice, I'll do 9,500' or so for longer durations in an unpressurized plane in the daytime. Lower at night unpressurized. Wonder if the event was at night. Flying (as pilot), you require supplemental O2 if you are over 12,500' pressure for 30 min, 14,000 it is a must. Seeing them set the internal pressure to half of the 'you must wear a mask' levels makes sense.