3 Airworthiness Directives: 1 airplane, 1 rotorcraft, 1 propeller.
AD 54-12-01 · published 1954
Martin-Marietta Corporation Airplanes
AD 54-13-01 · published 1954
Orlando Helicopter Airways, Inc., Sikorsky Aircraft Corporation Helicopters
AD 54-12-02 · published 1954
McCauley Propeller Systems Propellers