14 CFR §25.973
Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
Each fuel tank filler connection must prevent the entrance of fuel into any part of the airplane other than the tank itself. In addition—
- (a)[Reserved]
- (b)Each recessed filler connection that can retain any appreciable quantity of fuel must have a drain that discharges clear of each part of the airplane;
- (c)Each filler cap must provide a fuel-tight seal; and
- (d)Each fuel filling point must have a provision for electrically bonding the airplane to ground fueling equipment.