A Part 121 air carrier plans to conduct a revenue flight with an aircraft that has a seating capacity of 30 passengers. The flight will operate at an altitude where supplemental oxygen is required for the entire flight crew. According to 14 CFR 121.333, what is the minimum duration of supplemental oxygen supply required for this operation for each flight crewmember?
- AThe entire flight duration
- B2 hours
- C30 minutes
- D1 hour
Show answer & explanationAnswer & explanation
Correct answer: A. The entire flight duration
14 CFR 121.333(c)(2) states that for operations where supplemental oxygen is required, the oxygen supply for each flight crewmember must be at least the quantity of oxygen necessary to supply him or her for the entire flight time at those altitudes where supplemental oxygen is required, plus 15 minutes. While 15 minutes is an additional reserve, the core requirement is for 'the entire flight time' at those altitudes.
Why the other options are wrong
- B. This is incorrect; the requirement is for the entire time at altitude plus a reserve.
- C. This is the minimum for certain passenger requirements, not flight crew.
- D. This is incorrect; the requirement is for the entire time at altitude plus a reserve.
121.333 Flight Crew Oxygen Supply
14 CFR 121.333(c) specifies the minimum duration of supplemental oxygen supply for flight crew members in Part 121 operations. When supplemental oxygen is required, the supply must be sufficient for the entire flight time at those altitudes where it's needed, plus a 15-minute reserve.
- Applies when supplemental oxygen is required.
- Duration is for the 'entire flight time' at requiring altitudes.
- Includes an additional 15-minute reserve.
Memory trick: Entire flight at altitude, plus 15 to dilute!