special emergency (air piracy)
A condition in which an aircraft has been hijacked or another hostile act that threatens the safety of the aircraft and/or its passengers has been committed by a person(s) on board. The pilot of an aircraft reporting a special emergency condition should, circumstances permitting, apply distress or urgency radio-telephony procedures and give details of the special emergency. If circumstances do not permit the use of prescribed distress or urgency procedures, the pilot should transmit the nature of the special emergency on the air-to-ground frequency in use at the time. If unable to provide this information, the pilot should use code words and/or the transponder as follows: state “Transponder seven five zero zero” (meaning: “I am being hijacked/forced to a new destination”) and/or use the transponder setting “mode 3/A, code 7500.” Air traffic controllers will acknowledge and confirm receipt of the transponder code 7500 by asking the pilot to verify it. If the pilot does not acknowledge, the controller will assume that the aircraft has a special emergency and inform all concerned. The pilot will attempt to maintain an altitude between 10,000 and 25,000 and a speed of no more than 400 knots and fly toward the destination demanded by the hijackers. If these procedures result in either radio contact or an air intercept, the pilot will attempt to comply with any instructions received, which may direct the aircraft to an appropriate landing field.