22. Shutoff means -
(a) Engine compartment. C-46 engine compartments which comply with AD-62-10-2 or FAA approved equivalent meet the requirements of § 121.257 applicable to engine compartments, if, in addition, a means satisfactory to the Administrator is provided to shut off the flow of hydraulic fluid to the cowl flap cylinder in each engine nacelle. The shutoff means must be located aft of the engine firewall. The operator's manual must include, in the emergency portion, adequate instructions for proper operation of the additional shutoff means to assure correct sequential positioning of engine cowl flaps under emergency conditions. In accordance with § 121.315, this positioning must also be incorporated in the emergency section of the pilot's checklist.
(b) Combustion heater compartment. C-46 heater compartments which comply with paragraph (5) of AD-49-18-1 or FAA approved equivalent meet the requirements of § 121.257 applicable to heater compartments if, in addition, a shutoff valve located above the main cabin floor level is installed in the alcohol supply line or lines between the alcohol supply tank and those alcohol pumps located under the main cabin floor. If all of the alcohol pumps are located above the main cabin floor, the alcohol shutoff valve need not be installed. In complying with paragraph (5) of AD-49-18-1, a fail-safe electric fuel shutoff valve may be used in lieu of the manually operated valve.