Updated October 2026. Pilot rest rules protect time away from duty, but a legal roster and a well-rested pilot are not automatically the same thing. Sleep, circadian timing, time-zone changes and workload all affect fatigue. Understanding the distinction helps explain why an airline may need to delay a departure even when an aircraft is ready.
U.S. airline rest requirements
For operations covered by Part 117, 14 CFR 117.25 requires at least 10 consecutive hours of rest immediately before a reserve or flight duty period. That interval must provide at least eight uninterrupted hours of sleep opportunity. The rule also requires at least 30 consecutive hours free from duty within the preceding 168 consecutive hours before beginning reserve or a flight duty period.
These are rest provisions, not permission to fly for the remainder of a 24-hour day. Flight time, flight duty periods and cumulative limits have their own rules. The applicable limit depends on factors such as report time, segments, crew composition and the operation. Part 117 should not be presented as the rule for every cargo, charter or private flight.
European rules use their own framework
EASA’s air-operations framework contains separate flight-time limitation and rest provisions. Its basic home-base and away-from-base rest calculations consider the preceding duty as well as minimum durations; time-zone differences and particular arrangements can add requirements. Use the current EASA Easy Access Rules for Air Operations, especially ORO.FTL.235, rather than applying U.S. numbers to a European schedule.
Why sleep opportunity is different from sleep
Travel to a hotel, meals and preparation can consume part of an off-duty interval. A suitable rest opportunity also does not guarantee that a person actually sleeps well. Fatigue reporting and realistic scheduling therefore complement the numerical limits.
For passengers, a crew-rest delay can reflect a safety requirement that cannot be resolved by simply boarding sooner. For crew members, an overview like this is a starting point: the applicable regulations and approved company scheduling procedures determine what is legal for a particular assignment.