Flight time limitations exist to keep fatigue from quietly eroding safety, and the rules turn on a handful of terms that are easy to mix up.
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.
Four words to keep straight
Almost every fatigue rule is built from four ideas, and the EASA definitions (ORO.FTL.105) and the FAA Part 117 definitions (14 CFR 117.3) line up closely:
- Flight time is block time, measured from when the aircraft first moves for take-off until it comes to rest at the end of the flight. It is the narrowest of the four.
- Flight duty period (FDP) runs from when you report for a flight or series of flights until the aircraft finally comes to rest at the end of the last sector. It includes flight time plus the time on the ground between sectors.
- Duty is broader still: any task the operator requires, including the FDP, pre-flight and post-flight duties, training, and positioning.
- Rest is a continuous, protected period during which you are free of all duties.
A useful way to picture it: flight time sits inside the flight duty period, which sits inside duty, with rest as the counterweight that has to come before the next duty.
The ICAO baseline
Internationally, ICAO Annex 6, Part I requires each State to set flight time, flight duty period, and rest limits, and it allows an approved Fatigue Risk Management System (FRMS) as an alternative to fixed limits where the operator can show an equivalent level of safety. Annex 6 sets the obligation; the actual numbers are written by each authority, which is why an EASA limit and an FAA limit for the same situation are not the same figure. Never treat one authority's number as universal, and always check the version in force, because these limits are amended over time.
EASA and UK CAA limits
Under the EASA rules in Regulation (EU) 965/2012, Subpart FTL (and the UK CAA's retained version), the headline caps for commercial air transport are attributed as follows:
- Flight time is limited to 100 hours in any 28 consecutive days, 900 hours in any calendar year, and 1000 hours in any 12 consecutive calendar months (EASA ORO.FTL.210).
- Cumulative duty is limited to 60 hours in any 7 consecutive days, 110 hours in any 14 consecutive days, and 190 hours in any 28 consecutive days (EASA ORO.FTL.210).
- The basic maximum daily FDP for an acclimatised crew is 13 hours, reduced as the number of sectors rises and for start times that fall in the window of circadian low, with extensions allowed only in limited, defined circumstances (EASA ORO.FTL.205).
- Minimum rest at home base is at least as long as the preceding duty period or 12 hours, whichever is greater; away from base it is at least the preceding duty period or 10 hours, whichever is greater, and the away figure must allow an 8-hour sleep opportunity (EASA ORO.FTL.235).
FAA limits
In the United States, the equivalent rules for scheduled passenger airlines live in 14 CFR Part 117:
- Flight time is limited to 100 hours in any 672 consecutive hours (that is, 28 days) and 1000 hours in any 365 consecutive calendar days (FAA 14 CFR 117.23).
- The maximum flight duty period is not a single number but a table that depends on your report time and the number of flight segments, running up to roughly 14 hours for an unaugmented crew at the most favourable report times and reducing from there (FAA 14 CFR Part 117, Table B).
- Minimum rest before a flight duty period is at least 10 consecutive hours, including a minimum 8-hour uninterrupted sleep opportunity (FAA 14 CFR 117.25).
Part 117 applies to passenger operations conducted under Part 121. Operations under Part 135 and Part 91 have separate, historically less restrictive flight, duty, and rest rules, with FAA rulemaking under way to align some of them more closely with Part 117, so check the FAA for the current Part 135 requirements rather than assuming Part 117 applies.
Why the detail matters
These numbers are deliberately specific, and they differ by authority, by type of operation, and over time. The figures above are illustrative anchors with their source attached; they are not a substitute for the regulation in force for your operation. Standby, split duty, augmented crews, time-zone crossings, and disruptive schedules all change the picture, and an operator's approved scheme can be more restrictive than the baseline. When a calculation is close to a limit, go to the authority's current text.
In Pilot EFB
Pilot EFB can import your roster from a CSV file and work out flight time and duty totals across the rolling periods, so you can see at a glance when you are approaching a limit. It is a planning and awareness aid, not a compliance system: the limits that bind you are those in your operator's approved scheme and the current regulation, and Pilot EFB is not a certified Electronic Flight Bag. Saved roster data stays available offline; pulling a fresh roster needs a connection.