When is an aircraft on an IFR flight plan considered overdue if it has failed to report?

An aircraft on an IFR flight plan is considered overdue if it has failed to report 60 minutes after its estimated time of arrival. This timeframe is established to ensure safety and effective tracking of aircraft operating under instrument flight rules. If an aircraft does not report within this period, it raises concerns that the aircraft may be experiencing issues or emergencies, necessitating a search and rescue response. The 60-minute guideline allows sufficient time for delays that may be caused by weather, traffic, or other operational factors, while still prioritizing the safety and tracking of the aircraft. This standard is widely recognized in aviation practices to maintain situational awareness and operational safety.