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FAQ – Daily Flight Time Limitations.

A variety of factors contribute to whether an individual experiences fatigue as well as the severity of that fatigue.

The major factors affecting fatigue include:

• Time of day. Fatigue is, in part, a function of circadian rhythms. All other factors being equal, fatigue is most likely, and, when present, most severe, between the hours of 2 a.m. and 6 a.m.
• Amount of recent sleep. If a person has had significantly less than 8 hours of sleep in the past 24 hours, he or she is more likely to be fatigued.
• Time awake. A person who has been continually awake for a long period of time since his or her last major sleep period is more likely to be fatigued.
• Cumulative sleep debt. For the average person, cumulative sleep debt is the difference between the amount of sleep a person has received over the past several days, and the amount of sleep he or she would have received with 8 hours of sleep at night.
• Time on task. The longer a person has continuously been doing a job without a break, the more likely he or she is to be fatigued.
• Individual variation. Individuals respond to fatigue factors differently and may become fatigued at different times, and to different degrees of severity, under the same circumstances.

To address factors contributing to fatigue based upon time of day, the un-augmented flight time limitations in 117.11, the FDP limitations in 117.13, 117.15, 117.17 and 117.19; and the reserve limitations in 117.21(c) & (d); have been established.

To address factors contributing to fatigue based upon the amount of recent sleep, the rest requirements in 117.25(e) & (g); have been established.

To address factors contributing to fatigue based time awake, the FDP limitations in 117.13, 117.15, 117.17 and 117.19; and the reserve limitations in 117.21; have been established.

To address factors contributing to fatigue based cumulative sleep debt, the cumulative limitations in 117.23; the rest requirements in 117.25(b); and the consecutive nighttime operations in 117.27; have been established.

To address factors contributing to fatigue based time on task, the flight time limitations in 117.11; the FDP limitations in 117.13, 117.15, 17.17 and 117.19; have been established.

To address factors contributing to fatigue based individual variation, the provisions in 117.5 fitness for duty and 117.19(a)1) FDP extensions have been established.

There are three types of fatigue:

Transient fatigue is acute fatigue brought on by extreme sleep restriction or extended hours awake within 1 or 2 days.

Cumulative fatigue is fatigue brought on by repeated mild sleep restriction or extended hours awake across a series of days.

Circadian fatigue refers to the reduced performance during nighttime hours, particularly during an individual’s WOCL (typically between 2 a.m. and 6 a.m.).

The flight time limitations in 117.11; the FDP limitations in 117.13, 117.15, 117.17 and 117.19; the rest requirements in 117.25(e) & (g); and the reserve limitations in 117.21; addresses transient fatigue.

The FDP limitations in 117.11, 117.15 and 117.17; and the reserve limitations in 117.21(d); addresses circadian fatigue.

The cumulative limitations in 117.23 and the rest requirements in 117.25(b) & (d); addresses cumulative fatigue

The consecutive night time operations in 117.27 address the combination of cumulative fatigue induced by circadian fatigue over a series of consecutive days.

Q01) Does the FAA have any guidance concerning Fitness for Duty?

A01) Yes, AC 117-3 provides guidance.

AC 117-3

Q02) Does the FAA have any guidance concerning Fatigue Education and Training?

A02) Yes, AC 117-2 provides guidance.

AC 117-2

Q03) If a carrier is able to notify a pilot that their schedule has changed does the carrier use the new report time for starting/entering table B?

A03) This would be dependent upon as to when the pilot was informed.

Certainly ,if the schedule change will allow for a minimum rest period of 10 hours and with a sleep opportunity of 8 hours.

Possibly, should the FAA still maintain the 1 phone call policy during a layover? This would still be subject to requirement to have a rest period of 10 hours with a sleep opportunity of 8 hours.

Definitely not, if the crewmember is not informed until at time of scheduled report, that a new report time will be required and the crewmember will not be able to have a rest period of 10 hours with a sleep opportunity of 8 hours.

Scenario Question:

8 hours uninterrupted rest requirement

For example one of the crew members (ie a flight attendant’s) rest was interrupted by a smoke alarm 5 hours into the uninterrupted rest period.  However, the remaining crew members somehow slept through the alarm.

I would imagine that flight attendant could call in fatigued or agree to a certain amount of reasonable rest before continuing on.

The remaining crew rested and woke with the intention to operate the flight as scheduled despite the adjustment.

SQ1) What would be the liability for the remaining crew members?

SA1) The remaining Flightcrew members would still need to be able to operate the FDP within the limitations of part 117. The remaining cabin crewmembers would still be subject to the limitation in part 121 subpart P (and possibly part 117 should the options in 121.467 (c) be applied).

SQ2) Does the rest of the crew who say they are fine (whether they were actually awake or not) continue with the day and leave the flight attendant? 

SA2) Only if the required crew compliment (flight deck and cabin) is met for the scheduled operations.

SQ3) Or once the flight attendant contacts the company, the company then contacts the other crew members and resets their show time?

SA3) That is certainly possible, but I think we should refer to previous question (Q03/A03)

SQ4) Or if the company is unable to contact the remaining crew members and ends up leaving a voice mail message that is retrieved in the morning just before the crew is ready to leave for the airport, what happens to the crews report time?

SA4) Again, see answers provided in (Q03/A03)

Commentary on the scenario presented.

This actually sounds to be similar to a case of what happens when a crewmember becomes sick away from base. I would imagine that a certificate holder would have contingency procedures to leave one crewmember behind and possibly have a substitute crewmember (reserve) work the remainder of the assignment.

117.5  Fitness for duty.

(a)   Each flightcrew member must report for any flight duty period rested and prepared to perform his or her assigned duties.

(b)   No certificate holder may assign and no flightcrew member may accept assignment to a flight duty period if the flightcrew member has reported for a flight duty period too fatigued to safely perform his or her assigned duties.

(c)   No certificate holder may permit a flightcrew member to continue a flight duty period if the flightcrew member has reported him or herself too fatigued to continue the assigned flight duty period.

(d)   As part of the dispatch or flight release, as applicable, each flightcrew member must affirmatively state he or she is fit for duty prior to commencing flight.

117.9  Fatigue education and training program.

(a)   Each certificate holder must develop and implement an education and awareness training program, approved by the Administrator. This program must provide annual education and awareness training to all employees of the certificate holder responsible for administering the provisions of this rule including flightcrew members, dispatchers, individuals directly involved in the scheduling of flightcrew members, individuals directly involved in operational control, and any employee providing direct management oversight of those areas.

(b)   The fatigue education and awareness training program must be designed to increase awareness of:

(1)     Fatigue;

(2)     The effects of fatigue on pilots; and

(3)     Fatigue countermeasures

(c)    Education and Training Program Review:

(1)    Each certificate holder must update its fatigue education and awareness training program every two years and submit the update to the Administrator for review and acceptance.

(2)    Not later than 12 months after the date of submission of the fatigue education and awareness training program required by (c)(1) of this section, the Administrator shall review and accept or reject the update. If the Administrator rejects an update, the Administrator shall provide suggested modifications for resubmission of the update.

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FAQ – Daily Flight Time Limitations.