---
kind: "section"
citation: "14 C.F.R. § 25.971"
title: "14"
number: "25.971"
heading: "Fuel tank sump."
url: "https://uscodex.org/cfr/14/25.971"
---

# §25.971. Fuel tank sump.

- (a) Each fuel tank must have a sump with an effective capacity, in the normal ground attitude, of not less than the greater of 0.10 percent of the tank capacity or one-sixteenth of a gallon unless operating limitations are established to ensure that the accumulation of water in service will not exceed the sump capacity.
- (b) Each fuel tank must allow drainage of any hazardous quantity of water from any part of the tank to its sump with the airplane in the ground attitude.
- (c) Each fuel tank sump must have an accessible drain that—
  - (1) Allows complete drainage of the sump on the ground;
  - (2) Discharges clear of each part of the airplane; and
  - (3) Has manual or automatic means for positive locking in the closed position.

## Notes

### Authority

Authority: 49 U.S.C. 106(f), 106(g), 40113, 44701, 44702 and 44704; Pub. L. 115-254, 132 Stat 3281 (49 U.S.C. 44903 note).

### Source

Source: Docket No. 5066, 29 FR 18291, Dec. 24, 1964, unless otherwise noted.