Fuel supply: All domestic operations

This regulation sets minimum fuel requirements for Part 121 domestic flights. Before dispatch or takeoff, the aircraft must carry enough fuel to:

1. Fly to the destination airport 2. Continue to the most distant alternate airport (if an alternate is required) 3. Fly for an additional 45 minutes at normal cruise consumption after reaching the alternate

There's one exception: operators authorized for day VFR operations in nontransport category airplanes (type certificated after 1964) only need 30 minutes of reserve fuel instead of 45 minutes when conducting day VFR flights.

This ensures aircraft have adequate fuel reserves for unexpected delays, weather diversions, or other contingencies. The regulation builds in layers of safety—destination fuel plus alternate fuel plus time reserve—so pilots aren't forced into fuel-critical situations. Dispatchers and pilots must calculate these requirements before every flight, and the aircraft cannot legally depart without meeting them.

*This is a plain-English summary for study only. The official 14 CFR text on this page is controlling — always read the current regulation and consult a CFI.*