Air Crew Fatigue

Sleeping at the Wrong Time

By Richard R. Grayson, M.D.

Senior Aviation Medical Examiner, Geneva, IL.

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 performance.
  
• Two nights of normal sleep before flying greatly improve performance.
  
• 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 function.
  
• Naps are possible during the day, especially in the mid-afternoon sleepiness phase.
  
• 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 inertia).
  
• 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 improve alertness.
  
• 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 at night.”

Email Dr. Grayson with questions or comments: Richard@DoctorGrayson. com