Automatic communication method and system for an aircraft

An automatic communication method for an aircraft with at least one air traffic control center, the method comprising steps implemented automatically by electronic circuitry on board the aircraft of:

• a first step of receiving information relating to activation of automatic guidance of the aircraft along a contingency trajectory in a situation in which a pilot of the aircraft is incapacitated, the contingency trajectory corresponding to a trajectory determined automatically by an avionics system of the aircraft in response to detection of the situation in which the pilot is incapacitated;
• a second step of preparing then sending at least a first message on a first communication frequency selected before the activation of guidance of the aircraft along the contingency trajectory, the at least one first message to inform air traffic control of the activation of automatic guidance of the aircraft along the contingency trajectory, and of the sending of a further message or messages on a second communication frequency used for emergency communications;
• a third step of preparing then sending at least one second message on the second communication frequency, the second message to inform air traffic control of the activation of automatic guidance of the aircraft along the contingency trajectory;
• and
• a fourth step, while the aircraft is flying along the contingency trajectory, of receiving information relating to maneuvers that the aircraft will implement to follow the contingency trajectory, and preparing then sending a set of messages on the second communication frequency, the messages of the set of messages to inform air traffic control of maneuvers that the aircraft will implement.