14 C.F.R. § 27.969 Fuel tank expansion space.
Title 14 - Aeronautics and Space
Each fuel tank or each group of fuel tanks with interconnected vent systems must have an expansion space of not less than 2 percent of the tank capacity. It must be impossible to fill the fuel tank expansion space inadvertently with the rotorcraft in the normal ground attitude. [Amdt. 27–23, 53 FR 34213, Sept. 2, 1988]
Title 14: Aeronautics and Space
PART 27—AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT
Subpart E—Powerplant
Fuel System
§ 27.969 Fuel tank expansion space.
