Location of fuel tanks.
CFR · 2024-01-01 · US · Title 14
(a) Fuel tanks must be located in accordance with § 121.255. (b) No part of the engine nacelle skin that lies immediately behind a major air outlet from the engine compartment may be used as the wall of an integral tank. (c) Fuel tanks must be isolated from personnel compartments by means of fume- and fuel-proof enclosures.
official document · source cfr-2024 · id 14:§ 121.229