---
kind: "section"
citation: "14 C.F.R. § 25.967"
title: "14"
number: "25.967"
heading: "Fuel tank installations."
url: "https://uscodex.org/cfr/14/25.967"
---

# §25.967. Fuel tank installations.

- (a) Each fuel tank must be supported so that tank loads (resulting from the weight of the fuel in the tanks) are not concentrated on unsupported tank surfaces. In addition—
  - (1) There must be pads, if necessary, to prevent chafing between the tank and its supports;
  - (2) Padding must be nonabsorbent or treated to prevent the absorption of fluids;
  - (3) If a flexible tank liner is used, it must be supported so that it is not required to withstand fluid loads; and
  - (4) Each interior surface of the tank compartment must be smooth and free of projections that could cause wear of the liner unless—
    - (i) Provisions are made for protection of the liner at these points; or
    - (ii) **The construction of the liner itself provides that protection.**
- (b) Spaces adjacent to tank surfaces must be ventilated to avoid fume accumulation due to minor leakage. If the tank is in a sealed compartment, ventilation may be limited to drain holes large enough to prevent excessive pressure resulting from altitude changes.
- (c) The location of each tank must meet the requirements of [§ 25.1185(a)](/cfr/14/25.1185.md?p=a).
- (d) No engine nacelle skin immediately behind a major air outlet from the engine compartment may act as the wall of an integral tank.
- (e) Each fuel tank must be isolated from personnel compartments by a fumeproof and fuelproof enclosure.

## 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.