Parts departing aircraft
In aviation safety, parts departing aircraft or parts detached from aeroplanes (PDA), also known as objects falling off airplanes (OFA), things falling off aircraft (TFOA), and other analogous variations, can range from small fasteners like screws and rivets up to major sub-assemblies like hatch covers and doors. PDA are a safety concern because they may be critical parts needed to continue safe flight, may damage other critical parts of the aircraft as they depart, may cause foreign object damage to other aircraft, or may cause serious injuries or damage to people and property on the ground.