A pre-hung air inlet door assembly comprises an inlet door, a door box frame, and an actuation system. The door box frame is fastened to the support structure of an aircraft. The inlet door is operationally connected to the actuation system. The entire pre-hung air inlet door assembly can be pre-assembled for quick installation into an aircraft. Pre-assembly eliminates trimming operations and rigging and misalignment issues. The pivot shafts and bearing housings of the pre-hung air inlet door assembly can be accessed from outside the aircraft when repairs and/or replacement components are needed.