Flight duty period: Unaugmented operations

This regulation sets the maximum length of a flight duty period for operations with the minimum required crew (no extra pilots). Certificate holders cannot assign, and pilots cannot accept, any flight duty period that would exceed the limits specified in Table B of Part 117.

Two important adjustments apply:

If a pilot is not acclimated to the local time zone, two rules kick in:

• The maximum flight duty period from Table B is reduced by 30 minutes
• The limit is based on the time zone where the pilot was *last* acclimated, not the current location

This matters because it prevents fatigue by limiting how long pilots work during a duty period. The acclimation rules recognize that pilots operating in unfamiliar time zones face additional fatigue risks. Table B's limits vary based on the pilot's acclimated start time and number of flight segments, so you'll need to reference that table alongside this regulation.

*This is a plain-English summary for study only. The official 14 CFR text on this page is controlling — always read the current regulation and consult a CFI.*