14 CFR § 25.969 - Fuel tank expansion space.

---
identifier: "/us/cfr/t14/s25.969"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "14 CFR § 25.969 - Fuel tank expansion space."
title_number: 14
title_name: "Aeronautics and Space"
section_number: "25.969"
section_name: "Fuel tank expansion space."
chapter_name: "FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION"
subchapter_number: "C"
subchapter_name: "AIRCRAFT"
part_number: "25"
part_name: "AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES"
positive_law: false
currency: "2026-04-05"
last_updated: "2026-04-05"
format_version: "1.1.0"
generator: "[email protected]"
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)."
regulatory_source: "Docket No. 5066, 29 FR 18291, Dec. 24, 1964, unless otherwise noted."
cfr_part: "25"
---


# 25.969 Fuel tank expansion space.

Each fuel tank must have an expansion space of not less than 2 percent of the tank capacity. It must be impossible to fill the expansion space inadvertently with the airplane in the normal ground attitude. For pressure fueling systems, compliance with this section may be shown with the means provided to comply with § 25.979(b).

[Amdt. 25-11, 32 FR 6913, May 5, 1967]