How soon must a flight plan be closed if a specific search and rescue time is not included?

The requirement to close a flight plan in the absence of a specified search and rescue time is crucial for ensuring safety and efficient use of resources. Closing a flight plan no later than 1 hour after the estimated time of arrival (ETA) is mandated because it provides a reasonable timeframe for authorities to take action if the aircraft does not arrive as expected.

This timeframe allows for the coordination of search and rescue operations, ensuring that if an aircraft is delayed, the appropriate measures can be activated promptly. The 1-hour window is established to balance the need for timely search efforts with the understanding that there can be legitimate reasons for a delay that may not necessarily indicate an emergency.

In scenarios where the aircraft is overdue, a timely closure of the flight plan can significantly affect the search and rescue response, potentially saving lives. Therefore, adhering to this guideline is essential for aviation safety.