A dispatcher is planning a Part 121 flag operation under IFR. Under 14 CFR 121.645, in addition to fuel to fly to the destination and then to the alternate, what additional fuel reserve must be carried?
- A10 percent of the total fuel required to fly from departure to destination, plus 30 minutes of holding fuel at 1,500 feet above the alternate
- B45 minutes at normal cruising fuel consumption
- C30 minutes at normal cruising fuel consumption only
- D2 hours of fuel at maximum endurance airspeed
Show answer & explanationAnswer & explanation
Correct answer: A. 10 percent of the total fuel required to fly from departure to destination, plus 30 minutes of holding fuel at 1,500 feet above the alternate
14 CFR 121.645 for flag operations requires fuel to fly to and land at the destination, then a contingency fuel reserve of 10 percent of the total time required to fly from departure to destination, then fuel to fly to the alternate, and then fuel to fly for 30 minutes at holding speed 1,500 feet above the alternate airport. This differs from the domestic 45-minute reserve requirement of 121.639.
Why the other options are wrong
- B. 45 minutes reserve applies to domestic operations under 121.639, not flag operations.
- C. 30 minutes alone omits the required 10% contingency fuel for flag operations.
- D. 2 hours of fuel at maximum endurance is not a standard Part 121 fuel reserve requirement.
Flag Operations Fuel Requirements (121.645)
Fuel reserve rule for Part 121 flag operations requiring destination fuel, 10% contingency, alternate fuel, and 30-minute holding reserve.
- Fuel to destination first
- Plus 10% contingency of trip time
- Then fuel to alternate, plus 30 min holding at 1,500 ft
Memory trick: Flag flights: ten percent extra, then thirty more circling above the alternate.