When is an ALNOT considered cancelled?

An ALNOT (Alert Notification) is considered cancelled when the aircraft has been located or the search has been abandoned because this signifies that the immediate concern for the safety of the aircraft and its occupants has been resolved. The purpose of an ALNOT is to alert search and rescue organizations that an aircraft may be in distress or has not arrived at its destination as planned. Canceling the ALNOT appropriately indicates that either the aircraft is safe or that continued efforts to locate it are no longer deemed necessary, allowing resources to be redirected to other tasks or missions.

The other options do not represent the criteria for cancelling an ALNOT. For instance, filing a flight plan does not resolve an emergency situation, nor does establishing a search area indicate that the problem has been addressed. Similarly, a fixed period of time without communication does not automatically conclude the need for an ALNOT unless the situation regarding the aircraft has been definitively resolved. Hence, option C accurately captures the circumstances under which an ALNOT is officially cancelled.