14 C.F.R. § 121.229 Location of fuel tanks.
Title 14 - Aeronautics and Space
(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.
Title 14: Aeronautics and Space
PART 121—OPERATING REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS
Subpart J—Special Airworthiness Requirements
§ 121.229 Location of fuel tanks.
