46-13-02 LOCKHEED: (Was Mandatory Note 18 of AD-723-2). Applies Only to Model 18 Airplanes Used in Scheduled Air Carrier Operation.
Compliance required not later than April 30, 1946.
In order to comply with CAR Special Regulation 333, the present fuel system plumbing equipment shall be replaced with a dual fuel system in accordance with Lockheed Service Bulletin No. 18/SB-113, dated August 17, 1945, or any other dual fuel system approved by the Administrator.