The "Pilot Hour Rule" refers to the 1,500-hour rule required for a pilot to earn an Airline Transport Pilot (ATP) certificate in the U.S., which is necessary to fly for a commercial airline. Additionally, in 2026, pilots are governed by strict Flight Duty Time Limitations (FDTL) to manage fatigue. These rules generally cap "Flight Time" at 8 to 10 hours in a 24-hour period (depending on the start time) and "Flight Duty Period" (the total time they are at work) at 9 to 14 hours. Pilots must also have at least 10 consecutive hours of rest before a duty period, which must include an 8-hour "uninterrupted sleep opportunity." For 2026, the cumulative limits are also strict: a pilot cannot exceed 100 flight hours in 28 days or 1,000 flight hours in a calendar year.