Fuel supply: Nonturbine and turbo-propeller-powered airplanes: Supplemental operations

This regulation sets minimum fuel requirements for Part 121 supplemental operations using piston or turboprop airplanes.

For most flights, the airplane must carry enough fuel to:

• Reach the destination airport
• Then fly to the farthest alternate airport listed in the flight release
• Then fly for an additional 45 minutes at normal cruise (or 30 minutes for certain day VFR operations in non-transport category aircraft)

For flights outside the contiguous U.S., the reserve changes to either 30 minutes plus 15% of total flight time to destination and alternate, or 90 minutes—whichever is less.

If no alternate airport is required under §121.623(b), the airplane must carry enough fuel to reach the destination plus three hours of reserve fuel.

These requirements ensure adequate fuel margins for weather delays, routing changes, and unexpected conditions during supplemental operations with these aircraft types.

*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.*