Alerting Service
Shall be provided:
• for all aircraft provided with air traffic control service;
• as far as practicable, to all other aircraft having filed a flight plan or otherwise known to the air traffic services; and
• to any aircraft known or believed to be the subject of unlawful interference.
Flight Information Centers or Area Control Centers shall serve as the central point for collecting all information relevant to a state of emergency of an aircraft operating within the FIR or control area concerned and for forwarding such information to the appropriate rescue coordination center.
Without prejudice to any other circumstances that may render such notification advisable, air traffic services units shall notify rescue coordination center immediately an aircraft is considered to be in a state of emergency in accordance with the following:
Uncertainty Phase
• No communication has been received from an aircraft within a period of 30 MIN after the time a communication should have been received, or from
• the time an unsuccessful attempt to establish communication with such aircraft was first made, whichever is the earlier, or when
• an aircraft fails to arrive within 30 MIN of the estimated time of arrival last notified to or estimated by air traffic services units, whichever is the later,
Except when no doubt exists as to the safety of the aircraft and its occupants.
Alert Phase
• Following the uncertainty phase, subsequent attempts to establish communication with the aircraft or
• inquiries to other relevant sources have failed to reveal any news of the aircraft, or when an aircraft has been cleared to land and fails to land within five MIN of the estimated time of landing and communication has not been re-established with the aircraft, or when information has been received which indicates that the operating efficiency of the aircraft has been impaired, but not to the extent that a forced landing is likely, except when evidence exists that would allay apprehension as to the safety of the aircraft and its occupants, or when
• an aircraft is known or believed to be the subject of unlawful interference.
Distress Phase
• Following the alert phase, further unsuccessful attempts to establish communication with the aircraft and more widespread unsuccessful inquiries point to the probability that the aircraft is in distress, or when
• the fuel on board is considered to be exhausted, or to be insufficient to enable the aircraft to reach safety, or when
• information is received which indicates that the operating efficiency of the aircraft has been impaired to the extent that a forced landing is likely, or when
• information is received or it is reasonably certain that the aircraft is about to make or has made a forced landing.
Except when there is reasonable certainty that the aircraft and its occupants are not threatened by grave and imminent danger and do not require immediate assistance.
Source: EU-OPS