What it isThe total time a flight crew member is on duty for a flight, from showing up at work through landing the aircraft. Limited by FAA regulations to manage fatigue.

Why it mattersFlight duty period limits are the primary regulatory tool managing pilot fatigue. They balance operational demands with the cognitive performance research showing measurable decrements after ~12-14 hours of continuous duty.

Think of it like thisImagine a stopwatch that starts when you report for work and stops when the wheels touch down. Regulations cap that timer based on departure time, scheduled flights, and crew composition.

Per 14 CFR Part 117, a flight duty period is the time period a flight crewmember is required to be on duty for the purpose of conducting flight operations, beginning when the crewmember reports for the duty period and ending when the aircraft is parked after the last flight, with maximum duration set by departure time and flight count.

MechanismFDP limits in 14 CFR 117 vary based on the time of day duty begins, the number of flight segments, and crew augmentation. Limits are designed to prevent landings during conditions of severe cognitive fatigue. Cumulative duty limits prevent chronic accumulation. Rest period requirements before duty start ensure recovery opportunity.