FAR Part 117: Flight Time, Duty Periods, and Rest Rules

FAR Part 117 sets the flight, duty, and rest limits for pilots at U.S. passenger airlines. In plain terms: it caps how many hours you can fly, how long your workday can run from report to block-in, and how much rest you must get before the next assignment. The specific numbers depend on when you report, how many legs are scheduled, and how many pilots are in the cockpit. Both the airline and the pilot are on the hook for staying inside those limits.¹

Who Has to Follow Part 117

Part 117 covers flightcrew members at airlines operating passenger service under Part 121. That takes in the mainline carriers and the regional airlines that feed them. Responsibility is shared: the certificate holder cannot schedule a trip that breaks these rules, and the pilot cannot accept one.¹

Cargo-only Part 121 operations are not automatically covered. Those carriers stay under the older Part 121 Subpart Q duty rules unless they voluntarily opt in to Part 117, in which case the election has to apply to all of their flightcrew members.¹

Flight Time Limits

Flight time runs from the moment the aircraft first moves under its own power for flight until it comes to rest at the destination. Section 117.11 caps that time based on report time and the number of pilots on board.

For a standard two-pilot (unaugmented) crew, Table A sets the cap:

Report between 0000–0459 or 2000–2359: 8 hours of flight time
Report between 0500–1959: 9 hours of flight time

The lower number for late-night and early-morning reports reflects flying against the body clock.²

Augmented crews carry extra pilots who rotate through designated rest bunks or seats in flight. A three-pilot crew can fly up to 13 hours. A four-pilot crew can fly up to 17 hours. The higher caps exist because no one pilot is at the controls the whole time.³

Flight Duty Period Limits

The flight duty period (FDP) is broader than flight time. It starts when a pilot reports for duty intending to fly and ends when the aircraft is parked after the last segment with nothing further planned. Preflight briefings, taxi, deadhead positioning legs, and gaps between segments all count.⁴

Table B controls FDP for unaugmented operations and turns on two variables: report time and number of segments. The highest allowable FDP is 14 hours, and you only reach it by reporting between 0700 and 1159 with one or two segments scheduled. The lowest is 9 hours, which applies to any report between midnight and 0359 and also to evening reports paired with higher segment counts.¹

Two patterns matter. More segments shrink your FDP: a pilot reporting at 0600 gets 13 hours with one segment but only 10.5 hours with seven or more. And reporting during the window of circadian low, the period from 0200 to 0559, triggers the most restrictive limits.⁵

Split Duty

Section 117.15 gives unaugmented crews one narrow way to lengthen the workday. If the pilot gets a mid-duty rest break of at least three consecutive hours in a suitable accommodation, that break time does not count toward the FDP. A suitable accommodation is a temperature-controlled ground facility where the pilot can control light and noise and sleep in a bed, bunk, or flat or near-flat reclining seat. Hotel rooms qualify. Aircraft crew rest seats do not.⁶⁴

Rest Before Duty

Before any flight duty period or reserve assignment, the pilot must receive at least 10 consecutive hours of rest, measured from the moment the airline released the pilot from the previous duty. Inside that 10 hours, the airline must provide an uninterrupted 8-hour sleep opportunity. Uninterrupted means what it says: no schedule-change calls, no company contact, nothing that breaks the sleep window.⁷

The older rule required only 8 hours between arriving at the gate and reporting for the next flight, which in practice could shrink actual sleep to five hours or less once travel to the hotel and wind-down were factored in.⁸

On top of the daily minimum, every pilot must get at least 30 consecutive hours completely free from duty in every rolling 168-hour (seven-day) window. That longer break prevents sleep debt from building up across a run of legal but tiring days.⁷

Weekly and Monthly Caps

Section 117.23 layers cumulative limits on top of the daily rules so that hours can’t quietly stack up over weeks. All are rolling, not calendar-based, so the airline has to look backward across the relevant window every time it proposes a new assignment.

Flight duty period hours:

No more than 60 FDP hours in any 168 consecutive hours
No more than 190 FDP hours in any 672 consecutive hours

Actual flight time:

No more than 100 flight hours in any 672 consecutive hours
No more than 1,000 flight hours in any 365 consecutive calendar days⁹

Reserve and Standby

Section 117.21 handles pilots waiting for assignments rather than flying. On short-call reserve, the reserve availability period itself cannot exceed 14 hours. For unaugmented operations, reserve availability plus the resulting flight duty period cannot exceed the lesser of the Table B limit plus four hours, or 16 hours total. All of that time counts toward the cumulative caps.¹⁰

Long-call reserve gives more notice before report. If the airline assigns a long-call pilot to a duty period that begins before and extends into the window of circadian low, it must give at least 12 hours’ notice of the report time.¹⁰

Airport (standby) reserve is the strictest of the three. Time spent sitting at the airport waiting for an assignment counts directly as flight duty period, subject to the same FDP limits as active flying.¹⁰

When Things Run Long: Extensions

Section 117.19 allows limited flexibility for unforeseen circumstances. Before takeoff, the pilot in command and the airline together may extend the FDP by up to two hours beyond the Table B or C limit. Any extension of more than 30 minutes can only happen once before the pilot receives a full rest period, and no extension can push a pilot past the cumulative caps in Section 117.23.¹¹

After takeoff, the rules bend further. If something unexpected happens in the air, the pilot in command can extend the FDP as far as necessary to land safely at the next suitable airport, even if that exceeds cumulative limits.¹¹

An extension of more than 30 minutes triggers reporting. The airline must file a report with the FAA within 10 days describing the circumstances and, if the situation was within the airline’s control, the corrective steps it plans to take, which must be implemented within 30 days.¹¹

Fitness for Duty

Every numerical limit above sits on top of Section 117.5. A pilot who feels too fatigued to operate safely is legally prohibited from accepting the assignment, and the airline is equally prohibited from pressuring the pilot to take it. Each pilot must affirmatively state they are fit for duty as part of dispatch or flight release before every flight. If fatigue develops mid-duty and the pilot reports it, the airline cannot allow that pilot to continue the assignment.¹²

Operating Outside the Tables: FRMS

Some routes and schedules don’t fit the default framework. Section 117.7 lets a carrier exceed specific Part 117 limits if the FAA approves a Fatigue Risk Management System providing an equivalent level of safety. The FRMS must include a written fatigue risk management policy, ongoing fatigue education and awareness training, a fatigue reporting system for crews, a monitoring system to track fatigue across operations, an incident reporting process, and regular performance evaluation of the FRMS itself. The FAA reviews these programs closely and can revoke approval if the data shows the system is not holding a safety margin comparable to standard Part 117 limits.¹³

1
eCFR. 14 CFR Part 117 – Flight and Duty Limitations and Rest Requirements: Flightcrew Members
2
Legal Information Institute. 14 CFR Appendix Table A to Part 117 – Maximum Flight Time Limits for Unaugmented Operations
3
eCFR. 14 CFR 117.11 – Flight Time Limitation
4
eCFR. 14 CFR 117.3 – Definitions
5
eCFR. 14 CFR 117.3 – Definitions
6
eCFR. 14 CFR 117.15 – Flight Duty Period: Split Duty
7
eCFR. 14 CFR 117.25 – Rest Period
8
Federal Aviation Administration. Bombardier DHC-8-400
9
eCFR. 14 CFR 117.23 – Cumulative Limitations
10
eCFR. 14 CFR 117.21 – Reserve Status
11
eCFR. 14 CFR 117.19 – Flight Duty Period Extensions
12
eCFR. 14 CFR 117.5 – Fitness for Duty
13
eCFR. 14 CFR 117.7 – Fatigue Risk Management System