FAR 91.151 — VFR Fuel Requirements

This regulation requires that no person may begin a VFR flight unless there is enough fuel to fly to the first point of intended landing and, assuming normal cruising speed, to fly after that for at least 30 minutes during the day or 45 minutes at night. The extra night reserve accounts for the increased difficulty of finding an alternate landing site in darkness. Proper fuel planning is a critical cross-country skill, and running low on fuel remains a leading cause of preventable forced landings.