Supplemental oxygen requirements
When you must use supplemental oxygen depends on the cabin-pressure altitude and, in the middle band, how long you spend there (CAR 605.32). Two thresholds, 10,000 ft and 13,000 ft:
| Cabin altitude | Crew | Passengers |
|---|---|---|
| At or below 10,000 ft | none | none |
| Above 10,000 up to 13,000 ft | for the time beyond 30 min at that altitude | none |
| Above 13,000 ft | whole time | whole time |
Read it as three steps up:
- Below and up to 10,000 ft: nothing.
- 10,000 to 13,000 ft: only the crew, and only for the part of the flight that runs more than 30 minutes at that altitude. A short hop through this band needs nothing.
- Above 13,000 ft: everyone on board (crew and passengers) uses oxygen for the whole time up there, no 30-minute grace.
CAR 605.31 is the matching supply rule: you must carry enough oxygen for those required to use it, plus, in the 10,000 to 13,000 ft band, 10% of the passengers (and no fewer than one).
Trap: treating 10,000 ft as the line where oxygen is always required (it is 13,000 ft for full-time use), forgetting the 30-minute allowance in the middle band, or swapping the crew and passenger rules.
References
- CARs 605.31
- CARs 605.32