How long is a pre-flight (PR) inspection valid if the aircraft has not flown?

A pre-flight inspection is a critical safety measure that ensures an aircraft is in good working condition before flight. The validity of a pre-flight inspection is generally influenced by operational guidelines and regulations. In many jurisdictions, if an aircraft has not been flown after the inspection, the validity period is often extended to a duration of 72 hours. This means that as long as the aircraft remains on the ground and has not been operated, the checks conducted during the pre-flight inspection remain applicable for that timeframe.

Aircraft may be subjected to changing conditions that could affect their airworthiness. Therefore, the 72-hour window is set to balance safety with the practicalities of flight operations, notably when the aircraft is not being used. This allows pilots and crews to have confidence that the aircraft remains safe to operate within that timeframe without needing a complete re-inspection before each flight, reducing unnecessary delays while still adhering to safety standards.

In contrast, shorter time frames, such as 24 or 48 hours, would require more frequent inspections, which could be seen as impractical for aircraft that are being used less frequently or are kept in a stable condition on the ground. Therefore, the 72-hour validity accurately captures the necessary safety considerations while allowing for operational efficiency.