Air Crew Fatigue
Sleeping at the Wrong
By Richard R. Grayson, M.D.
Senior Aviation Medical Examiner, Geneva,
An ex-trucker patient of mine
once confided that the reason he was retired on disability was because he had
fallen asleep on a cold winter’s night at the wrong time. His 18-wheeler crossed the median of a
divided highway in Indiana while he nodded off. The truck jackknifed and
ejected him through the windshield. I
was the only one he had ever told that his accident was caused by falling
asleep at the wheel.
The literature on pilot fatigue
and aircraft, train, and automobile accidents due to sleepiness is voluminous.
There are many articles about “go” and “no-go” drugs used legally in the
military, which are not legal for United States civilian pilots. A good list of official recommendations is
reproduced below: (from The Federal Air Surgeon's Medical Bulletin • Summer 2002 By
Virgil D. Wooten, MD)
“Extensive government research
into fatigue has yielded important information about techniques to improve
performance and safety during prolonged and/or night-time flying. Basic
principles to keep in mind are listed below. Naps are defined as intentional
sleep lasting less than half the length of the major sleep period.
- Do not overwork or under-sleep before flying
- Naps taken before and at the beginning of flights at night improve
- Two nights of normal sleep before flying greatly improve
- Two nights of normal sleep at the end of an operation are necessary
to recover from the effects of sleep deprivation.
- A night off in a long series of night operations helps restore
- Naps are possible during the day, especially in the mid-afternoon
- Naps are a stopgap approach to improve performance and safety for
limited periods of time, not an indefinite substitute for long sleep
periods during biological night.
- Make an attempt to anchor sleep when sleeping in a different time
zone by getting some of the sleep during home base sleeping hours.
- The longer the nap, the better the improvement in performance.
- The longer the nap, the longer it takes to awaken (more sleep
- Longer and harder operations require more napping.
- At least 20 minutes should be allowed to awaken from a nap to allow
dissipation of sleep inertia.
- Noise and activity help dissipate sleep inertia.
- When possible, engage in conversation, stretch, and move about to
- Caffeine can help maintain alertness but may disrupt sleep if used
too close to desired sleep times.
- Alcohol use may interfere with sleep quality and performance.
- Napping will not promote circadian adjustment to night flying.
- Relaxation techniques and sleep hygiene can assist napping and
adjustment to a new circadian schedule.
- The napping environment should be as free as possible from noise,
light, temperature extremes, and interruptions.
- Use the bed primarily for sleep.
- Avoid looking at the time. Set an alarm and ignore the time.
- Avoid alcohol, caffeine, and heavy meals before bed.
- Schedule a worry time, planning session, and wind-down time before
getting into bed. Make lists of things to do the next day.
- Make the bedroom quiet, comfortable, dark, and secure. Use
white-noise generators if the environment is noisy. Minimize disruptions.
- Get out of bed after lying awake for more than 20 minutes-do
something boring or try relaxation techniques.
- Avoid exercise and hot baths within 3 hours of bedtime.
- Exercise regularly, in the morning or afternoon.
- Keep a regular bedtime and get-up time.
- Do not spend excessive amounts of time in bed, e.g., if you can
sleep only 7 hours, spend no more than 7.5 hours in bed.
- Avoid excessive napping, which can interfere with your ability to sleep
Dr. Grayson with questions or comments: Richard@DoctorGrayson. com