FAA Aircraft Dispatcher (ADX)Regulations (Part 121)Medium
For a Part 121 domestic operation under IFR, 14 CFR 121.639 requires the aircraft to carry enough fuel to fly to the destination airport, then to the alternate (if required), and then for how much additional time at normal cruising fuel consumption?
- A60 minutes
- B90 minutes
- C30 minutes
- D45 minutes
Show answer & explanationAnswer & explanation
Correct answer: D. 45 minutes
14 CFR 121.639 requires domestic operators to dispatch an airplane with enough fuel to fly to the destination, then to the alternate if one is required, and then to fly for 45 minutes at normal cruising fuel consumption. This is distinct from the flag/supplemental fuel rules, which use different additional time requirements.
Why the other options are wrong
- A. 60 minutes applies to some supplemental operations, not domestic.
- B. 90 minutes is not a standard domestic fuel reserve figure.
- C. 30 minutes is not the domestic reserve requirement.
Domestic Fuel Requirements (121.639)
Regulation specifying minimum fuel a Part 121 domestic flight must carry: to destination, then alternate (if required), then 45 minutes reserve.
- Applies to domestic operations under Part 121
- Reserve fuel calculated at normal cruise consumption
- Different reserve times apply to flag (121.641) and supplemental operations
Memory trick: Domestic dispatchers 'Forty-Five' minutes to spare