FAA Airline Transport Pilot (ATM)Regulations (14 CFR 117/121/61)Medium
A dispatcher is preparing the release for a Part 121 domestic scheduled flight requiring an alternate airport. Under 14 CFR 121.639, in addition to fuel to fly to the destination and then to the alternate, what additional fuel reserve must be included?
- A45 minutes of fuel at normal cruising fuel consumption
- B30 minutes at holding speed at 1,500 feet above the alternate
- CAn additional 10% of the total trip fuel burn
- D60 minutes of fuel at normal cruising fuel consumption
Show answer & explanationAnswer & explanation
Correct answer: A. 45 minutes of fuel at normal cruising fuel consumption
14 CFR 121.639 (domestic operations) requires fuel sufficient to fly to the destination airport, then to the alternate, and then to fly for 45 minutes at normal cruising fuel consumption. This is distinct from the 30-minute flag/international reserve.
Why the other options are wrong
- B. 30 minutes at holding speed is not the domestic reserve standard.
- C. A percentage-based reserve is not the domestic rule.
- D. 60 minutes is not specified for domestic operations.
Domestic Fuel Reserve (121.639)
Minimum fuel reserve required for Part 121 domestic operations beyond destination and alternate fuel.
- Fuel to destination, then to alternate, then 45 min at normal cruise
- Applies to domestic (not flag/international) operations
- Flag operations under 121.645 instead require a 30-minute reserve
Memory trick: "Domestic = 45, Flag = 30."