4 Airworthiness Directives: 1 rotorcraft, 1 engine, 2 propeller.
AD 54-01-03 · published 1954
Orlando Helicopter Airways, Inc., Sikorsky Aircraft Corporation Helicopters
AD 54-02-01 · published 1954
Textron Lycoming, AVCO Corporation Engines
AD 54-01-01 · published 1954
Hamilton Standard Division Propellers
AD 54-01-02 · published 1954
Hamilton Standard Division Propellers