AhaBulb: Stuff Everyone Should Know · ahabulb.com/pilot-oxygen-crew-12500
Above 12,500 up to 14,000 feet cabin altitude, when must the required crew use oxygen?
For any part of the flight there longer than 30 minutes.
- For any time there beyond 30 minutes ✔
- The entire time at those altitudes
- Only at night
Why: Rule 91.211 lets crew fly above 12,500 up to 14,000 feet for 30 minutes without oxygen. After that, they must use it. Above 14,000 feet, they must use it the whole time.
Huh, didn't know that: Above 15,000 feet cabin altitude, every person on board must be provided with supplemental oxygen.
Which bird is always out of breath? A puffin.
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References
Answer: For any time there beyond 30 minutes. Rule 91.211 lets crew fly above 12,500 up to 14,000 feet for 30 minutes without oxygen. After that, they must use it. Above 14,000 feet, they must use it the whole time.
- 14 CFR 91.211 Supplemental oxygen (eCFR) www.ecfr.gov/current/title-14/chapter-I/subchapter-F/part-91/subpart-C/section-91.211
for that part of the flight at those altitudes that is of more than 30 minutes duration.
Checked 2026-10-07.
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