FAA Aircraft Dispatcher (ADX)Regulations (Part 121)Medium
A Part 121 domestic flight is being planned. Under 14 CFR 121.639, what is the minimum fuel supply required for a turbojet aircraft to be dispatched under IFR, assuming no alternate airport is required?
- AEnough fuel to fly to the destination, plus 1 hour at normal cruising speed.
- BEnough fuel to fly to the destination, plus 45 minutes at normal cruising speed.
- CEnough fuel to fly to the destination, then to the most distant alternate, plus 45 minutes.
- DEnough fuel to fly to the destination, plus 30 minutes at normal cruising speed.
Show answer & explanationAnswer & explanation
Correct answer: B. Enough fuel to fly to the destination, plus 45 minutes at normal cruising speed.
For a Part 121 domestic operation under IFR, 14 CFR 121.639 requires that a turbojet aircraft must carry enough fuel to fly to the destination airport, and thereafter to fly for 45 minutes at normal cruising fuel consumption.
Why the other options are wrong
- A. 1 hour is incorrect; the regulation specifies 45 minutes.
- C. This option describes a scenario where an alternate is required, which is not the premise of the question.
- D. 30 minutes is incorrect; the regulation specifies 45 minutes.
Domestic Fuel Requirements (121.639)
Specifies the minimum fuel supply for Part 121 domestic operations, ensuring sufficient reserves for safe flight.
- Varies based on IFR/VFR and presence of alternate.
- Always includes fuel to destination.
- Additional reserve time required.
Memory trick: Domestic IFR Fuel: 'D' for Destination, 'I' for IFR, 'F' for Forty-Five minutes, 'M' for Minimums.