[CodeToad]

My classes were seasoned aviators. Maybe that was the diff. Several of us at could go all day performing complex tasks, checklists, etc. Studs, I guess.

[superfries]

http://www.c-f-c.com/supportdocs/abo4.htm

Average Effective Performance Time for flying
personnel without supplemental oxygen:

15,000 to 18,000 feet ..........30 minutes or more

22,000 feet ...............................5 to 10 minutes

25,000 feet .................................3 to 5 minutes

28,000 feet............................2 1/2 to 3 minutes

30,000 feet .................................1 to 2 minutes

35,000 feet ............................30 to 60 seconds

40,000 feet ............................15 to 20 seconds

45,000 feet ..............................9 to 15 seconds