FAA Aircraft Dispatcher (ADX)Regulations (Part 121)Hard
A Part 121 flight is experiencing a sudden depressurization at FL380. The flight crew initiates an emergency descent. Under 14 CFR 121.333, what is the minimum continuous flow oxygen supply required for each passenger in a pressurized aircraft if the cabin pressure altitude remains between 10,000 feet and 14,000 feet for more than 30 minutes?
- A10 minutes of oxygen.
- B30 minutes of oxygen.
- C2 hours of oxygen.
- D60 minutes of oxygen.
Show answer & explanationAnswer & explanation
Correct answer: D. 60 minutes of oxygen.
14 CFR 121.333(c)(2) states that for operations where the cabin pressure altitude is expected to remain between 10,000 feet and 14,000 feet for more than 30 minutes, each passenger must be provided with supplemental oxygen for the entire period above 10,000 feet, but in no case less than 60 minutes.
Why the other options are wrong
- A. 10 minutes is the requirement for pilot oxygen above FL350, or for passengers above FL250 if no pilot above FL350.
- B. 30 minutes is the threshold for when the 60-minute passenger oxygen requirement kicks in, not the duration itself.
- C. 2 hours is not a standard regulatory requirement for passenger oxygen in this specific scenario.
Passenger/Crew Oxygen Tiers (121.333)
Regulations outlining the minimum supplemental oxygen requirements for Part 121 aircraft, varying by altitude, duration, and occupant type (crew vs. passenger).
- Different requirements for flight crew and passengers.
- Mandated at specific cabin pressure altitudes.
- Ensures safety during depressurization events.
Memory trick: Oxygen Rules: 'O' for Oxygen, 'X' for X-tra, 'Y' for Yellow masks, 'G' for Guts (to remember the numbers). Passenger '60' minutes if 10-14k for >30min.