FAR Part 117 and FAR 110, 119 & 121: FTDR

FAR Part 117

Flight and Duty Time Limitations and Rest Requirements: Flightcrew Members.

FAR Part 110

General Requirements

FAR Part 119 Subpart B

Applicability of Operating Requirements to Different Kinds of Operations Under Parts 121, 125, and 135 of This Chapter

FAR Part 121 Subpart Q

Flight Time Limitations and Rest Requirements: Domestic Operations

FAR Part 121 Subpart R

Flight Time Limitations: Flag Operations

FAR Part 121 Subpart S

Flight Time Limitations: Supplemental Operations

FAR Part 121 Subpart P

121.467 Flight Attendant Duty Period Limitations and Rest Requirements: Domestic, Flag, and Supplemental operations.



20 thoughts on “FAR Part 117 and FAR 110, 119 & 121: FTDR

    1. In reality it is based upon the time zone an individual is currently acclimated to.
      This is important to understand when evaluating how an individual could be exposed to conditions which may lead to fatigue, when compared to the prescriptive rules in part 117.

      For example, a FCM who lives in Indianapolis, but is based in Chicago, would for Physiological reasons have his WOCL in the same time zone as Indianapolis; since the difference is so little (1 hour) individual variations and proper rest strategies could permit this difference to be overcome.

      For the FAR interpretation, it is assumed to start off as Local Base time.
      Once a FCM acclimates to a new time zone, it will be assumed to be the time zone the FCM has acclimated to; eg. FCM Flys from JFK to LHR and laysover for 48 hours, the next WOCL following the layover is based upon LHR time, even if the FCM has returned to the same time zone as JFK.

      The only sections under part 117 impacted by the definition of the WOCL are 117.27 Consecutive nighttime operations, and 117.21 Reserve status (d) Long Call Reserve. You should also review the rules concerning acclimatization.


      1. FAR 117 wasn’t written to accommodate commuters. Living outside your base is totally optional, it was written to work with FCM that work where they live.


        1. While I agree that FAR 117 does not provide any firm statuatory requirements as how Airlines and Flightcrew Members need to deal with “Commuting”, some Airlines do have policies for “commuters”.
          In the end the FCM is responsible to adhere to 117.5


  1. What happens if a pilot finishes his or her flight at 10pm and is schedule to be on long call reserve at midnight? Is there a rest period of ten hours before he or she can be contacted for a long call assignment?


    1. In my humble opinion,
      It is legal, however before the FCM may begin a FDP, ASB or SCR, they must be given a 10 hour rest period with a 8 hour sleep opportunity.
      Should the ASB or FDP start before the WOCL and Extend into the WOCL, the FCM must be given a 12 hour notification of assignment
      The time on LCR is not included in the calculations of cumulative FDP limits in 117.23(b).
      The LCR is also not rest, so the time from 22:00 to 00:00 plus any time on LCR is not included in the 30 hours rest period in 168:00.

      Always check the OPSPEC and check with the FAA should you have further questions.


  2. I was on short call reserve and flew a two day trip that ended at 2345 with a 13 hour FDP on the second day. I was put on long call reserve at 0001 (16 min later). I read 117.21 to say all reserve is considered Long call unless stated as short/airport. I also read 117.25(a) to say I am required to have a rest period before being assigned another reserve. My company doesn’t read it that way. Who is correct?


    1. Randy,
      It may not be nice, but I think it is legal.

      Long-Call (LCR) is not considered rest, so before you can accept a short-call reserve (SCR) assignment or a FDP you must be placed into a rest period that provides 10 hours rest and 8 hours sleep opportunity. You also must be able to look back 168 hours and find that you have had 30 consecutive hours free of duty before starting any reserve or FDP.

      If your company is considering (LCR) as rest, then you may have a good reason to have further discussion.


  3. What if you duty off at 8:15 pm due to delays, wx, mechanical and are scheduled for a 6am show then next day. Is that illegal due to Physiological night rest 0100-0700? Can they just push your show time back 15 minutes or do they have to put you on reserve?


    1. Hannah,
      The physiological night rest (PNR) 0100-0700 only pertains to a FCM who has operated out side of home base theater and has been away from base for 168 hours or more, in which base the FCM must be give 3 PNRs and no less than 56 hours rest before the next FDP/Reserve; 117.25(d) refers.

      In the situation you have presented, 8:15 pm (20:15) off, with a scheduled FDP start at 6:00, the FCM will NOT have a 10 hour rest period immediately before report (20:00 to 06:00) with a 8:00 sleep opportunity within those 10 hours, the FCM must be first placed into long call reserve and the FDP is re-secheduled to start at 6:15 or later. The letters of clarification referred to this particular situation. You should also refer to 117.25(e).



  4. This new rule caused us nothing but inconvenience on our way back from Aruba. Our Delta flight was forced to land in Orlando to switch pilots which delayed us & t he entire plance missed connection in Atlanta. Three other planes had the same issue coming out of international airports. This meant standing in line behind 1000 people. We had to wait in line to go through customs again even though we went through in Aruba. We had to stand in line for hours waiting for our hotel vouchers since we could not fly out until the next morning. We had to stand in line or the shuttle. We had to stand in line at the hotel to check in. We got to bed at 3:00 a.m. & had to be up at 6:00 a.m. to catch our flight from Atlanta to Huntsville.We had no dinner as everything was closed & we had lunch at 11:00 a.m. in Aruba. We were pretty hungry by 3:00 a.m. By the time we got home we were exhaused. All of this occurred due to this new rule. Thanks federal government for making our trip home a nightmare!


  5. So….just want to make sure I’m not missing anything. My airline is now operating under 117 rules. I have a 3 day trip starting tomorrow. If I complete that trip as scheduled, I will be at 29 hours and 55 minutes of block in the previous 7 days. However, if we go over block by 6 minutes before my last leg, can I still do that last flight? Is there no longer a 30 hours in 7 days rule? Thanks.


    1. Ben,
      With respect to FAR 121 30 hrs FT in 7 days, it is a scheduled limitation, so the old cliche applies “Legal to start legal to finish”.
      117 no longer has 30 in 7, now there is a 60 hour FDP limit in any 168 hours. The FAA is interpreting this as a hard limit that cannot be exceeded if known before takeoff.


  6. I have read through part 117 many times already do not see any limitations that would apply to how long a pilot can be on duty (except reserve FDP +4 or 16 hours)
    For example; a pilot ends a 13 h FDP at an outstation and the company schedules him or her for a 4 hour sit and a DH back to domicile which could add up to 16+ hours of continued duty. It seems like a DH at the end of the day does not count towards FDP.
    Am I missing something or there really is NO limit on duty?


    1. Your observation is correct, there is no specific Duty Time Limit. However should the time in DHD transportation exceed the Table B limits a compensatory rest that is at least as long as the time in DHD transportation will be required, such rest may not be less than 10 hours. 117.25(g) refers.


  7. Thank you for putting this together. My question is how does the FAA define 8 hours of uninterrupted sleep opportunity? Does this mean behind the door at the hotel? If so, that does not allow for 8 hours of sleep. Maybe 7 if you’re good at showing real fast.



    1. David,
      That is a valid question.
      While a rest period is simple to measure, a consecutive ten (10) hours period immediately before start of FDP or Reserve that is free from duty, it is in the 10 hour rest period that the 8 hour uninterrupted sleep opportunity must be provided and taken by the crew member. Now obviously, should the time from release to report is 11 hours but it takes and 1:45 to travel each way, to and from the “Hotel” that would only provide 7:30 of sleep. The crewmember must advise the airline how long it will be necessary to get the 8 hours of sleep, ref 117.25(f). The air carriers should also ensure that ground sleep accommodations are within a reasonable distance, less than 2 hours, since the sleep opportunity must fall within the 10 hour rest period that immediately precedes the FDP/Reserve. Crew members have a joint responsibility to actually utilize the sleep opportunity and ensure that it will fall within the 10 hour rest period. The airline should further recognize other factors when computing travel times, personal hygiene and proper nutrition (meals), these factors may reduce the permitted travel time from 2 hours to as little as 30 minutes. The airline also needs to ensure that the travel time to the rest facility will permit for the full 8 hours of uninterrupted of sleep.

      I suggest readers review FAA circular AC 117-3


  8. The max 8 hours flight time applies to duty periods.
    It is however possible to legally fly more than that in a 24 hour period, which is what the [soon to be old] rule applies to. (example: late duty period on day one and an early duty period on day two)


    1. Your observation is correct, the new rules will permit a Flightcrew member to exceed 8 hours of Flight Time in a 24 hour period. However, the old rules also permitted to do the same, it is that under FAR 121 subpart Q, the lookback rest was determined using the flight time in 24.


  9. So, what I don’t get is the fact that the minimum rest requirements had been in increase from 8 hrs to 9 hrs.
    However, if schedule for more than 8 but less than 9 hrs they have to give you 10 hrs on the ground. I always thought that is illegal to schedule for more than 8 hrs except for international fly with more than 2 crew members.
    Here is another thought, what happens to the circadian rhythm friendly schedules????
    MMMmmmm, I think they forgot about that in the new law.

    Thanks for taking the time to review the site.

    With FAR 117 the basis is to always have a rest period immediately preceding the FDP/Short-Call reserve assignment of no less than 10 hours with a sleep opportunity of 8 hours. There is no longer a reduced rest / compensatory rest concept as found in 121.471.

    Daily Flight Time for 2 -Pilot crews is now either 8 hours or 9 hours, this is a hard limit, no longer will the “Legal to Start/Legal to Finish” cliche apply.

    With regards to the circadian friendly schedules, the rules actually address issue, both the Daily Flight Time limits and the Daily FDP limits are dependent upon the Flightcrew members scheduled report time. There are also limitations for FDP that operate during the WOCL.



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