When does a flight duty period (FDP) begin?

The beginning of a flight duty period (FDP) is defined as when aircrew first reports for official duty. This encompasses all the time spent in preparation for a flight, which starts with the initial reporting for duty rather than any specific tasks or actions that occur after reporting, such as safety briefings or arriving at the aircraft.

This definition is important for regulatory compliance and fatigue management. Aircrew members must be mindful of their FDP to ensure they are operating within established limits, promoting safety for both the flight crew and passengers. Thus, understanding that the clock starts ticking upon reporting for duty allows aircrew personnel to effectively manage their rest periods and ensure they are fit for duty when it's time to operate the aircraft.