Definition
A regulated period during which a flightcrew member is on duty for the purpose of conducting a flight. It begins when the crew member is required to report for duty with the intention of operating a flight, a series of flights, or a positioning flight, and ends when the aircraft is parked after the last flight and there is no plan for further aircraft movement by the same crew member. Flight Duty Period limits are set by regulation (under 14 CFR Part 117 for Part 121 operators) and vary based on report time and number of flight segments.
Plain English
The clock that runs from the moment a pilot reports for work expecting to fly, until the aircraft is parked at the end of the day's flying. The rules cap how long this period can last so pilots aren't on the job too long.
Context Anchor
Seen in airline and commercial crew scheduling, flight-time limits, rest rules, and fatigue-management discussions.
Why Pilots Care
It sets the legal maximum time a pilot may work before required rest, directly protecting against fatigue-related safety risks and ensuring regulatory compliance.
Intuition Check
Do not read Flight Duty Period as only the time spent flying. It includes the required report time before the flight and the time between flight segments, up to the end of the last assigned flight movement.
Example Sentence 1
The captain checked the schedule and confirmed the four-leg trip would fit within the maximum Flight Duty Period allowed for a 0600 report time.
Example Sentence 2
Weather delays pushed the end of the flight duty period later than planned, triggering an extended rest requirement.