SESKStuff Everyone Should Know
SESK: Stuff Everyone Should Know · sesk.info/comm-oxygen-thirty

At cabin pressure altitudes above 12,500 and up to 14,000 feet, crew must use oxygen after how much time?

More than 30 minutes at those altitudes.

Start playing free

  1. More than 10 minutes
  2. More than 30 minutes ✔
  3. More than 1 hour

Why: Under 91.211(a)(1), the required minimum flight crew must use supplemental oxygen for the part of the flight at those altitudes that is of more than 30 minutes duration. Above 14,000 feet, the crew uses oxygen the entire time.

Huh, didn't know that: Above 15,000 feet, every occupant must be provided with oxygen.

The dad joke
What do you call a plane that can't take off? An error plane.
Like this card?
Play the game

References

Answer: More than 30 minutes. Under 91.211(a)(1), the required minimum flight crew must use supplemental oxygen for the part of the flight at those altitudes that is of more than 30 minutes duration. Above 14,000 feet, the crew uses oxygen the entire time.

  1. 14 CFR 91.211 Supplemental oxygen (Cornell LII eCFR mirror) www.law.cornell.edu/cfr/text/14/91.211
    that part of the flight at those altitudes that is of more than 30 minutes duration
    Checked 2026-10-10.

Think this answer is wrong? Tap "Challenge this answer" on the card in the game and tell us why.

Test yourself in the game

FlyingAbove what cabin pressure altitude must supplemental oxygen be provided to every occupant of the aircraft?FlyingCabin pressure altitude is between 12,500 and 14,000 feet MSL. After how long must the required crew use oxygen?FlyingWhich airplanes must be operated with a designated second in command under 91.531?

That's stuff everyone should know.