AAM-510 Fatigue

SAS REDAC Projects Review 

Fatigue Mitigation in Flight Operations 

FAA Fatigue Management Working Group 

February 23, 2021 

Presented by: Thomas E. Nesthus, Ph.D. 
 

 

 

 

Fatigue Mitigation in Flight Operations (2021) 

1. Continue collection and entry of data into the FAA Fatigue Risk

Management System (FRMS) database; evaluate data and formulate HF

research questions to improve understanding of flight crewmember

fatigue during operations that exceed the limitations of 14 CFR Part 117

regulations. 

• Results of this research provides information on specific safety

performance indicators and helps identify objective improvements in

flight ops the new regulations have achieved, such as reduced internal 

flight operations fatigue reports, reduced fatigue-related ASAP reports,

improved measures of sleep, performance, and flightcrew mood. 

• Knowledge gleaned from these improvements will inform development

of operational requirements, standards, conditions, limitations,

mitigations, and FRMS authorizations relevant to these flight

operations issues. 

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rrier A 

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(LACP) 

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FDP Max 

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FDP +Ext 

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Fatigue Mitigation in Flight Operations (2021) 

Examples of approved FRMS operations & the need for data 

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Fatigue Mitigation in Flight Operations (2021) 

2. Conduct operational study to understand pilot performance and HF issues 

caused by high frequency, multiple segment, short haul flights that do not 

exceed the limitations of 14 CFR Part 117. This study will provide the FAA with

operational SH fatigue data, that does not currently exist. 

• Short-Haul Study designed to improve understanding of human factors/pilot

performance issues during multiple segment, short haul flight operations 

• To characterize the effects of workload and cumulative sleep loss across trip

pairings: 

 evidence shows that early start times, nighttime arrivals, and the number of segments

flown during a duty day contribute the most to short haul pilot workload-related fatigue 

 majority of research examining workload and sleep restrictions in these operations rely

primarily on subjective reporting and offer few recommendations 

 few studies have experimentally examined how the implementation of recommendations

decreases risk or to compare the efficacy of imposed countermeasures 

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Fatigue Mitigation in Flight Operations (2021) 

Short-Haul, Multi-segment Flight Operations are conducted within 

table limits for Flight Time and Flight Duty Period. 

• Very little data available regarding the impact on sleep, workload, 

and performance, even though SH comprises significant share of 

U.S. airlines’ daily operations 

• Public Law 111-216, § 212(B) Fatigue Risk Management Plan 

(FRMP), provides carrier’s with a mandate to manage fatigue, but 

not reported to FAA 

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Fatigue Mitigation in Flight Operations (2021) 

• Mitigation strategies limited due to flight operations and unaugmented crew complement 

• A significant amount of night flying is found in these operations 

• Regulations provide 10 hr between FDPs, but circadian rhythm 

issues often affect quantity & quality sleep pilots receive 

• Rest/napping/sleep opportunities are restricted; U.S. regulations 

do not allow in-cockpit napping 

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Fatigue Mitigation in Flight Operations (2023) 

3. Longitudinal Study of Long Haul / Ultra-Long-Range Operations 

• Evaluate behavioral adaptation of pilots to multiple time zone 

shifts associated with long-haul and ultra-long-range flight 

operations and capture pilot performance data 

• Apply results to refine operational requirements, standards, 

conditions, limitations, and mitigations relative to fatigue, thereby 

using a “data-driven systemic safety approach to identify risks, 

enhance standards and programs, and evaluate continued 

effectiveness.” 

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Fatigue Mitigation in Flight Operations (2023) 

Long Haul / Ultra-Long-Range Flight Operations 

• For domestic travel across continental US, science shows 

circadian rhythms re-adjusts to new time zones by ~1.15 hr per 

day 

 re-entrainment occurs on average 92 min later each day after westward 

flights and 57 min earlier each day after eastward flights 

• But science is unclear when >4 times zones have been crossed 

• New FRMS data suggests pilots are not fully acclimating on 

routes per the § 117.3 definition, whereby acclimation occurs after 

either 36 consecutive hrs free from duty or 72 hrs in theater 

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Fatigue Mitigation in Flight Operations (2023) 

Long Haul / Ultra-Long-Range Flight Operations 

• Since there is not clear scientific consensus on acclimation rates 

for flights crossing 4 or more time zones... 

 recovery of one day per time zone crossed is a common suggested 

guideline amongst the scientific community 

• Anecdotal evidence suggests behavioral adaptation and 

maintenance of performance may occur, but the range of 

influence is unknown 

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Fatigue Mitigation in Flight Operations (2023) 

Study Objectives: 

1) To systematically evaluate the behavioral adaptation of pilots to 

multiple time zone changes associated with long-haul (LH) and ultra long

range (ULR) flight operations 

a. To investigate the rate of behavioral adaptation to new time zones

from base and/or differences between east vs. westbound adaptations 

b. To utilize a study population with exposure to repeated time zone

changes typical of commercial LH/ULR aviation crews 

2) To develop a pilot profile of behavioral adaptation across typical 

LH/ULR transmeridian flight operations 

3) To investigate the degree to which behavioral tactics modulate crew

performance across time zones under operational conditions typical of

the aviation industry 

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FAA Fatigue Management Working Group 

Workgroup Purpose: 

• Formalize communication across types of operations with 

consideration for stakeholder concerns and priorities for aviation

fatigue research 

• Prioritize fatigue research recommendations and capitalize on

overlapping opportunities, in-house assets, pooling of resources, and

industry collaboration 

• Meet annually with all stakeholders to re-assess priorities and research 

gaps relating to fatigue 

(NOTE: The workgroup data/findings do not necessarily result in funded

research, but provides critical information to policy offices to prioritize

decisions for research, synergy across operations, resource pooling, and

collaboration) 

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FAA Fatigue Management Working Group 

• Internal FAA meeting held with government representatives from 

each type of operation 

• Expanded operations subgroups to include policy-holders, 

industry-stakeholders, and labor and conducted introductory 

teleconferences 

• Post Subgroup Meeting(s): compiled and documented research 

prioritizations and identified respective fatigue research priorities, 

justification of research needs, and opportunities for synergy with 

other sub-groups 

• Currently, Subgroup meeting minutes drafted and reviewed. A 

combined report is under development 

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UAS Operator Fatigue (2021) 

• Survey to gather information on current practices for pilots of

unmanned aircraft systems (UAS). 

 Target information gathered is the common fatigue-related practices, and 

the minimum knowledge, skills, abilities (KSAs), testing, and staffing

procedures required for operating UAS 

 Information to be collected will be used to inform future rulemaking and 

the development of supporting guidance 

 Necessary because existing regulatory framework, to include the

certification of airmen, was not designed with remote pilots in mind. 

 To broadly integrate UAS and remote pilots into the NAS, further

rulemaking will be required to address remote pilot certification for air

carrier operations and flight and duty time limits applicable to remote pilot 

air carrier operations 

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