The Human Factor: Fighting Fatigue

Part 2 of a 3 part series on how pilots can battle fatigue.



(February 2011) — Last month in "Deadly Fatigue," I established that a pilot cannot win the fight against fatigue. Sooner or later fatigue will win and the pilot will fall asleep or make a mistake that he or she would never have made when well rested. However, even though we can never win this battle, there are practical ways a pilot can manage fatigue and reduce the chances of falling asleep at the controls or making a mistake that results in damage, injury or death.

It is generally well-known that the average person needs around eight hours of sleep every night to be well-rested. It turns out that most people don’t get that much sleep, with the average person in the United States sleeping about 6½ hours per night. That means that many people are getting less than that, and by the end of the week they are more than a full night behind in their sleep. Although the impact is not as severe as if they had stayed up an entire night, studies show that lack of sleep has a very negative impact on judgment, memory, attention and mood. It also leads to an increase in “microsleeps,” brief episodes of sleep that can occur without warning and without people being aware of what is happening until they wake up.

The term for this kind of result is a sleep debt. Just as continuous withdrawals from a bank account will overdraw an account, continuous withdrawals from a person’s sleep account will overdraw that account too. In the case of a bank account, once you repay the extra money you withdrew, your account is no longer overdrawn. In the case of a sleep dept, it typically takes two full nights’ sleep to erase an accumulated sleep debt. While it is a good idea to be well-rested before an especially tiring trip, it is not possible to “bank” extra sleep to prepare for an extended period without sleep.

Many pilots battle fatigue, as evidenced by the fact that about a quarter of the Aviation Safety Reporting System reports cite fatigue as a factor. Agricultural pilots sometimes fly at night when the winds are calm. One pilot described flying just above the crop, head nodding as he struggled to stay awake, or even suddenly waking up from a few seconds of microsleep. Airline pilots have to deal with varying schedules, changing time zones and noisy hotels. Corporate and charter pilots often fly to their destination early in the morning and then wait around all day for an evening departure and a long flight at night back to the departure point.

The greatest challenge Charles Lindbergh faced on his record-breaking flight was not bad weather or navigation, but fatigue. He started his flight with a serious sleep deficit. The night before the flight, his excitement made it hard for him to sleep, and what little sleep he did get was interrupted by people coming in the room with questions. Only nine hours into his 33-hour flight he describes how his “whole body argues that nothing, nothing life can attain, is quite so desirable as sleep.”

One of the greatest risks of fatigue is that we are able to get away with flying when we are tired. Charles Lindbergh made it to Paris. The agricultural pilot I spoke with made it home. Airline, corporate and charter pilots complete their flights even though they are struggling to stay awake and working to recover from errors made in the fog of fatigue. Because of this we get complacent. Fatigue becomes just a fact of life. We joke or even brag about the times fatigue almost got the best of us but we managed to pull through, and we ignore the compelling evidence that fatigue is implicated in a significant percentage of incidents and accidents.

Many jobs require full mental clarity, and flying an airplane is certainly one of them. Since flying in a fatigued state is similar to flying when inebriated, the first step in managing fatigue is to take it just as seriously as alcohol. In place of the “eight hours from bottle to throttle” rule, we could institute a “16 hours from alarm to snooze” rule. A pilot who has been awake for 16 hours is approaching a mental state equivalent to a blood-alcohol concentration of 0.04, so that pilot should be in bed, not in the cockpit.

Because of the role fatigue has played in recent airline accidents, the FAA has proposed extending the minimum rest period for Part 121 pilots to nine hours to allow pilots time to travel to wherever they intend to rest, get a full eight hours of sleep and then return to the airport. This is still cutting it a little short, but it is certainly a step in the right direction. It’s also proposing a reduction in the maximum duty time from 16 hours a day to between nine and 13 hours, depending on things like time of day (or night), time zone changes, etc.

However, just because the FAA makes a rule about time available for rest or maximum duty time for Part 121 pilots does not mean that pilots use the rest time for the intended purpose, and there are no rules for pilots operating under Part 91, so it is up to each pilot to establish his or her own common-sense rules and practices to successfully manage fatigue. A good starting point would include:

• Conduct a fatigue self-assessment as part of every day and every flight.

• Count back from when you have to get up, set a firm time to be in bed and stick to it.

• Avoid “sleep stealers” such as the 10 o’clock news or late shows that entice you to keep watching with brief descriptions of what’s “coming up.”

• If you are sleepy all the time even though you seem to be getting enough sleep, you may be in the 30 percent of people who have a sleep disorder. Visit your doctor or a sleep clinic.

• If you frequently change time zones or are experiencing more trouble getting to sleep as you age, consider using melatonin to help you get to sleep, but avoid using sleeping pills unless absolutely necessary.

• Be aware that as we age it takes longer to recover from a sleep deficit.

• Use an eye mask if you can’t darken the room completely.

• Use earplugs and white noise to avoid being disturbed by others. I have loaded a white noise DVD (purewhite on my laptop, and I turn on the repeat function so it will play all night long, adjusting the volume depending on the ambient noise.

• If you are hungry, have a light snack before you go to sleep.

• Limit or delay the use of caffeine until you really need it — for example, just before an instrument approach in the middle of the night.

• If you have a long layover, consider going to a hotel so you can rest and even have a good nap before your return flight.

• If you can’t do that, at least try to get in a 30-minute power nap, using an eye mask and music or white noise playing through a headset.

• Realize that in no way does a nap on a sofa in a crew room or on a red-eye flight replace a good night’s sleep!

• Stay in good physical shape through regular strength and aerobic exercise.

• Be especially careful during the two low points in most people’s circadian rhythm — from 3 to 5 a.m. and from 3 to 5 p.m.

• Ask your passenger to call you about an hour before arriving at the airport for the return flight so you can be fully awake and ready to go.

• If a passenger arrives unexpectedly while you are napping, politely insist that you will need a few minutes to wake up and be safe to fly.

• If you work for a company that pushes you to fly when you are tired, show your manager this article and politely but assertively suggest that a more realistic rest policy is much less expensive in the long run than an accident.

• If you find yourself behind the “fatigue power curve,” don’t try to push on. Instead, land and get some rest.

We will never know how many accidents were due more to the fatigue level of the pilot than to other factors, or how many unexplained accidents were the result of the pilot falling asleep. You can make sure that fatigue never ends your flying career by altering your living patterns to ensure you are getting enough sleep, by getting quality rest when you are tired and by stopping whenever fatigue begins to get the upper hand.