Rest is the other half of every fatigue rule. Flight time and duty limits cap how much you can work; rest requirements set how much recovery has to come before you work again. Get the rest wrong and the whole scheme falls apart.
This is general educational information, not operational, legal, or regulatory advice. Rules differ by authority and change over time. Always verify against current official sources and follow your operator's approved procedures.
What rest actually means
A rest period is a continuous, uninterrupted period during which you are free of all duties and have a genuine opportunity to sleep. The emphasis on uninterrupted and free of all duties is deliberate: time spent positioning to or from an airport, or carrying out any task the operator requires, is duty, not rest. The definitions sit in EASA ORO.FTL.105 and FAA 14 CFR 117.3, and both frameworks are built on the idea that rest has to provide a real chance to sleep, not just a gap in the schedule.
Minimum rest before a duty: EASA
Under the EASA rules in ORO.FTL.235, the minimum rest you must be given before a flight duty period depends on where you are:
- At home base, the rest must be at least as long as the preceding duty period, or 12 hours, whichever is greater.
- Away from home base, it must be at least the preceding duty period, or 10 hours, whichever is greater, and that period shall include an 8-hour sleep opportunity in addition to the time for travelling and physiological needs.
Read that second bullet twice, because the preposition is the rule. The 8 hours is in addition to the travel and the physiological needs, not something you carve out of the 10 while "taking them into account". The acceptable means of compliance is arithmetic about it: AMC1 ORO.FTL.235(b) allows 1 hour for physiological needs and then says that if the travelling time to the accommodation is more than 30 minutes, the operator increases the rest period by twice the amount by which it exceeds 30 minutes - twice, because you make the journey in both directions. A 50-minute transfer, then, does not quietly eat 40 minutes of your sleep. It adds 40 minutes to your rest.
So after a 13-hour duty at home base, the minimum rest is 13 hours, because that is greater than 12. After a 9-hour duty away from base, the minimum is 10 hours, because that is greater than 9. And notice how that 10 is built: 8 hours of sleep opportunity, plus the AMC's 1 hour for physiological needs, plus an hour of travel (30 minutes each way). The three add up to the minimum rather than competing for it, which is exactly why a longer transfer has to lengthen the rest instead of shortening the sleep.
Minimum rest before a duty: FAA
Under the FAA rules in 14 CFR 117.25, the structure is different:
- The rest period before beginning a flight duty period must be at least 10 consecutive hours, and it must provide the crew member a minimum 8-hour uninterrupted sleep opportunity.
- Separately, no crew member may be assigned to a flight duty period unless they have had at least 30 consecutive hours free from duty in the preceding 168 hours, the weekly recovery rest.
The FAA figure is a flat 10 hours rather than a greater-of test, but with the same insistence on a protected 8-hour sleep opportunity inside it.
The sleep opportunity, and weekly rest
Two ideas run through both systems and are worth holding onto:
- The sleep opportunity. A rest period is only as good as the sleep it allows. A nominal 10 or 12 hours eaten into by a long transfer to a hotel does not leave the protected 8-hour sleep opportunity intact, which is why EASA writes the 8 hours as being in addition to travel and physiological needs, and why the AMC lengthens the rest when the transfer runs long rather than letting it come out of the sleep.
- Recurrent rest. Rest before a single duty is not enough on its own to prevent fatigue building up over days, so both systems require a longer recurrent rest, and both put a number on it. The FAA requires 30 consecutive hours free from duty in any 168 consecutive hours. EASA's ORO.FTL.235(d) requires a recurrent extended recovery rest period of at least 36 hours including 2 local nights, with never more than 168 hours between the end of one and the start of the next, increased to 2 local days twice every month. EASA's is the longer of the two, and it is a fixed figure, not something left to the operator's scheme.
A worked example
A pilot finishes a duty period of 11 hours at home base. Under EASA, the minimum rest before the next FDP is the greater of the preceding duty (11 hours) and 12 hours, so 12 hours. The same pilot, finishing an 11-hour duty down route, would need the greater of 11 hours and 10 hours, so 11 hours, with the 8-hour sleep opportunity protected. Under the FAA scheme, the rest before the next FDP would be at least 10 consecutive hours with the 8-hour sleep opportunity, and the roster would also have to show 30 hours free of duty somewhere in the last 168. Different rules, different numbers, same underlying purpose.
Reduced rest, disruptive schedules and recovery
The minimum rest figures are the normal case, but two real-world complications sit alongside them, and both are governed by the operator's approved scheme under the EASA rules.
Reduced rest. Some approved schemes permit a rest period shorter than the standard minimum under defined and limited conditions, with compensation built in afterwards. Reduced rest is not a free shortening of the day; it is a bounded exception with strings attached, typically a longer subsequent rest to make up for it. Because it depends on the operator's specific approval, the binding figures are in that scheme, not in a general rule of thumb.
Disruptive schedules. The rules recognise that not all duty is equally tiring. An early start, a late finish, and a night duty are treated as disruptive because they cut across the body's natural sleep period, and they carry their own constraints on how they can be combined and how much rest must follow. A run of early starts, for instance, steadily erodes sleep even if each individual rest period meets the minimum, which is exactly the kind of cumulative fatigue the recurrent weekly rest exists to clear.
Recovery takes real time. This is the principle underneath the weekly rest. Sleep debt does not clear in a single night; after a demanding block of duties, the body needs an extended period, including the chance for two full nights of sleep, to recover. Both systems say so with a number: the FAA's 30 consecutive hours free from duty in any 168 consecutive hours, and EASA's 36-hour recurrent extended recovery rest period including 2 local nights, never more than 168 hours apart. Note that EASA's figure names the two nights explicitly, which is the physiology written into the rule. A schedule can satisfy every single pre-duty minimum and still be fatiguing if it never allows that proper recovery.
The thread through all of it is that the minimum rest before a duty is necessary but not sufficient. The pattern of duties across the week, the timing of those duties against the body clock, and the recurrent recovery all matter, and the operator's approved scheme is where the detailed limits live.
A worked rest calculation
Follow a short trip to see the minimums in action, remembering that the binding figures are in the operator's scheme and the regulation.
Day one, a pilot flies an 11-hour duty ending at home base. Under EASA ORO.FTL.235, the minimum rest before the next duty is the greater of the preceding duty (11 hours) and 12 hours, so 12 hours.
Day two, after that rest, the pilot flies a 9-hour duty ending down route, away from base. The minimum rest there is the greater of the preceding duty (9 hours) and 10 hours, so 10 hours, and that 10 hours must contain the protected 8-hour sleep opportunity in addition to the travel and the hour for physiological needs. Suppose the hotel is a 50-minute drive from the aerodrome. That is 20 minutes beyond the AMC's 30, so under AMC1 ORO.FTL.235(b) the operator increases the rest by twice the excess, 40 minutes, and the minimum rest becomes 10 hours 40 minutes. The sleep does not shrink to pay for the drive; the rest grows.
Day three, the pilot positions home and finishes another duty. Across the whole trip, on top of these pre-duty rests, the roster must also deliver the recurrent extended recovery rest: 36 hours including 2 local nights under EASA, with never more than 168 hours between one and the next.
Under the FAA, the same trip would be read against 14 CFR 117.25: at least 10 consecutive hours before each flight duty period, each containing an 8-hour uninterrupted sleep opportunity, plus 30 consecutive hours free from duty somewhere in the preceding 168 hours. The numbers differ from the EASA ones, and you would not mix them, but the structure is the same: a minimum before each duty, a protected sleep opportunity inside it, and a longer recurrent rest across the week. Reading the two systems side by side makes the shared logic plain: every figure, whether a greater-of test or a flat minimum, exists to guarantee a real chance to sleep before the next duty and a genuine recovery across the week. That is why the protected sleep opportunity, rather than the headline number of hours, is the part of any rest calculation to look at hardest.
Common pitfalls
- Counting positioning as rest. Travel and any required task is duty; rest is protected time.
- Taking the 8-hour sleep opportunity out of the travel time. Under EASA away from base it is 8 hours in addition to travelling and physiological needs, and a transfer over 30 minutes lengthens the rest rather than shortening the sleep.
- Forgetting weekly rest, or thinking EASA leaves it vague. It does not: 36 hours including 2 local nights, never more than 168 hours apart, against the FAA's 30 hours in 168.
- Mixing the schemes. The EASA greater-of test and the FAA 10-hour minimum are different rules; do not apply one authority's figure under the other.
- Assuming the minimum is the target. Like every minimum, it is a floor, and a tired crew benefits from more.
In Pilot EFB
Pilot EFB can track your duties from an imported roster and time the rest between them, so you can see at a glance whether the gap before your next duty meets the minimum you expect. It is a planning and awareness aid, not a compliance system: the binding rest requirements are those in your operator's approved scheme and the current regulation, and the figures differ by authority and operation. Pilot EFB is not a certified Electronic Flight Bag. Saved roster data stays available offline; pulling a fresh roster needs a connection.