Final answer:
A flight plan or itinerary should be closed not more than one hour after the estimated time of arrival (ETA) to avoid unnecessary Search and Rescue operations. This is a critical aspect of aviation safety and operations.
Step-by-step explanation:
The question pertains to the procedures involved in closing a flight plan or flight itinerary in the context of aviation operations. In general, a flight plan should be closed not more than one hour after the estimated time of arrival (ETA). If there is no filed Search and Rescue (SAR) time, a flight itinerary should be closed not more than one hour after the ETA as well. The actual time may vary depending on the specific regulations of the country in which the flight is operating.
Closing a flight plan or itinerary in a timely manner is important for aircraft operations because it signals that the aircraft has landed safely and helps ensure that Search and Rescue operations are not initiated unnecessarily. If a flight plan is not closed within the stipulated timeframe, authorities may begin SAR procedures based on the assumption that the aircraft is overdue or missing.