Management of Sleep and Fatigue in Military Aviation

Management of Sleep and Fatigue in Military Aviation

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Updated November 18, 2022
Management of Sleep and Fatigue in Military Aviation
In recent years, Congress has expressed concern over the
Military aviators may experience sleep deprivation and
effects of sleep deprivation on servicemember health and
fatigue due to a variety of factors, including inhospitable
military readiness, as well as its impact on military aviation
sleep environments, operational demands, unpredictable
safety. Aviators in all military services of the Department of
schedules, long-duty days or flight durations, challenging
Defense (DOD) with high operational, psychological, and
flight conditions, and circadian-rhythm disruption due to
physiological demands may experience sleep deprivation
crossing multiple time zones, known as chronodisruption.
and fatigue. To counter these effects, the military services
In a March 2021 report to Congress, DOD stated sleep
use mitigation strategies (i.e., non-pharmacological and
deprivation has “significant effects on the physical,
pharmacological measures) to enhance aviator safety and
cognitive, and emotional functioning needed for readiness,
prevent aviation mishaps. This In Focus provides an
occupational, and operational mission fulfillment.” The
overview of those mitigation strategies and offers issues for
report also described the “risk of accident in training,
congressional consideration.
operational, and combat environments significantly
increases if Service members are sleep deprived.”
Background
The U.S. Centers for Disease Control and Prevention
Fatigue Management in Military Aviation
estimates 32.5% of adults do not meet the Healthy People
Each military service is responsible for implementing its
2030 (HP2030) criteria for sufficient sleep. In comparison,
own policies and procedures to mitigate aviator fatigue and
the 2018 DOD Health Related Behaviors Survey estimated
sleep deprivation. The military services use varied
77.7% of active duty servicemembers did not meet HP2030
approaches to mitigate aviator fatigue, including (1)
criteria. HP2030 categorizes sufficient sleep as at least
administrative and behavioral (i.e., non-pharmacological)
seven hours in a 24-hour period. Research indicates a
measures, and (2) the voluntary use of pharmacological
variety of detrimental health effects arise from both acute
measures. Regulations for each service consistently
and chronic sleep deprivation.
emphasize non-pharmacological measures as the primary
means of mitigating fatigue.
Sleep deprivation and fatigue are two distinct physiological
states. The National Institutes of Health defines sleep
Administrative and Behavioral Measures
deprivation as a condition that occurs when someone “[does
Administrative and behavioral measures vary by service
not] get enough sleep.” Sleep deprivation is a contributor to
and airframe, but all services limit the length of an aviator’s
fatigue. The National Institute for Occupational Safety and
duty day, total flight hours over a given period, and
Health defines fatigue as a “feeling of weariness, tiredness
standards for rest and time available for sleep. The military
or lack of energy.” Sleep deprivation and fatigue can be
services also educate aviators on the impact of sleep loss
most apparent when an individual is awake counter to their
and the benefits of consistent sleep.
circadian rhythm (i.e., during the circadian trough of
Pharmacological Measures
alertness), typically apparent during the early morning
Historical Use of Pharmacological Measures. The U.S.
hours (see Figure 1).
military historically has approved pharmacological
measures for aviators in certain mission contexts. For
Figure 1. Relative Level of Alertness and Wakefulness
example, the Air Force and Navy have authorized the use of
Based on Time of Day
pharmacological measures for select missions and aircrew
during combat operations, at least since the Vietnam War.
The operational needs for these measures have been
scrutinized and are an area of review. For example, the Air
Force suspended the use of stimulants between 1996 and
2001. After considering survey results from pilots flying
during Operation Desert Storm and four placebo-controlled
studies, the Air Force validated the need and utility of the
measures and rescinded the suspension.
Current Use. Sustained high-operations tempo over the
past several decades, among other factors, has generated
persistent demand for the use of pharmacological measures.

The military services authorize aviation medicine
Source: CRS graphic adapted from Shappell, et al., Crew Rest and
specialists (i.e., flight surgeons) to prescribe U.S. Food and
Duty Restrictions for Commercial Space Flight, available at
Drug Administration (FDA)-approved pharmacological
https://rosap.ntl.bts.gov/view/dot/34244.
agents as a fatigue management measure when
administrative and behavioral measures are known or
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Management of Sleep and Fatigue in Military Aviation
expected to be insufficient. No DOD-wide policy
Aeromedical Policy Letter on Pre-deployment Rest or
standardizes the situations or conditions for use of
Sustained Operations Agents authorizes prescription
pharmacological measures. Each military service sets its
stimulants for aviators. The Air Force delegates authority
own policies for which aviators may use pharmacological
for stimulant use to its Major Commands. In turn, Air Force
measures and under which conditions. The services are all
Major Commands restrict stimulant prescriptions to fighter,
similar in limiting pharmacological measures to specific
bomber, and certain reconnaissance aircraft pilots.
operational circumstances, establishing a process by which
Sedative-hypnotics. Typically, a flight surgeon may
authorization for use is conducted (e.g., in both medical and
prescribe sedative-hypnotics, commonly called no-go pills,
command channels), limiting the amounts prescribed and
for limited periods and with commander approval, to aid in
duration of use, and monitoring use by flight surgeons. In
sleep initiation when an operational need exists. Situations
all services, use of pharmacological measures by aviators is
might include inhospitable sleep settings, the need to shift
voluntary. Figure 2 lists the pharmacological agents used in
sleep schedules, or crossing multiple time zones. In a 2021
fatigue management.
report to Congress, DOD cautioned sedative-hypnotics have
Figure 2. Pharmacological Agents Authorized for
a “wide range of side effects” that can impact readiness.
Fatigue Management in Aviators and Aircrews
Some side effects include drowsiness, disinhibition,
impaired cognition, learning deficits, and increased risk of
vehicle accidents. To mitigate some effects, regulations
prohibit aviators from flying for specific periods of time
after ingesting, based on drug type. Flight surgeons must
monitor aviators’ use of the drugs and level of fatigue.
Federal Aviation Administration (FAA)
Management of Fatigue
Similar to the services’ non-pharmacological measures,
FAA regulations stipulate a variety of fatigue mitigation
regulations for pilots conducting commercial flights. Some
measures include maximum duty time, rest requirements,
and number of consecutive nights of flying. FAA
regulations do not permit the use of stimulants. However,
FAA-certified medical examiners may authorize the use of
sedative-hypnotics (including some not authorized by
DOD) and melatonin supplements for occasional or limited
use by civilian pilots.
Source: CRS graphic based on DOD’s “Study on Effects of Sleep
Deprivation on Readiness of Members of the Armed Forces,” and
Questions for Aviation Oversight
analysis of FDA drug data at http://www.accessdata.fda.gov/scripts/
The following lines of inquiry may assist Congress in
cder/daf.
considering military aviation safety and support
Notes: *Typical y experienced with doses higher than those used by
congressional oversight of DOD programs and initiatives to
the services. **When used at prescribed doses. All refers to al
prevent sleep deprivation and fatigue.
services in DOD, except the U.S. Space Force. FDA defines “abuse”
Impacts to Military Operations and Readiness
as the intentional, non-therapeutic use of a drug to achieve a desired
psychological or physiological effect. “Dependency” refers to a
 What lessons-learned from non-pharmacological or
physical or psychological dependence where individuals experience
pharmacological measures in aviation can be applied to
symptoms of withdrawal or have impaired control over drug use.
other military occupations (e.g., naval vessel crew,
medical personnel, special operations)?
Stimulants. When prescribed by a flight surgeon and

authorized by the aviation unit’s senior medical officer
How do authorized pharmacological measures affect the
risk for substance use or abuse among aviators?
(e.g., colonel or Navy captain), aviators may opt to utilize
 What opportunities do human performance optimization
stimulants of two types, commonly called go-pills, to
efforts (e.g., biotechnologies, biometrics) offer to
counter fatigue and improve alertness and performance.
manage sleep and fatigue among aviators?
Service policies require flight surgeons to issue limited
quantities, monitor aviators, and collect unused
Effectiveness of Fatigue Management Strategies
medications. Selected aviators may be prescribed
 What scientific consensus exists regarding the
dextroamphetamine. The FDA classifies this stimulant as
having a “hi
effectiveness of current methods to prevent or mitigate
gh potential for abuse” and prolonged use “may
lead to drug dependence.”
fatigue and sleep deprivation in DOD aviators?
Air Force policy also allows the
 What DOD efforts are in progress to identify novel or
use of the non-amphetamine-based stimulant, modafinil.
emerging fatigue management strategies?
The FDA recommends observation for “signs of misuse or

abuse,” and notes
What impact would arise from creating a DOD-wide
modafinil can produce “psychoactive and
policy on fatigue management strategies in aviation?
euphoric effects…and feelings typical of other [central
nervous] stimulants.”
Patrick Parrish, National Defense Fellow
The military services’ policies differ by authorizing which
Bryce H. P. Mendez, Acting Section Research Manager
aviators may receive stimulants. For example, a 2003 Army
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Management of Sleep and Fatigue in Military Aviation

IF11881

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