To nap or not to nap?

Crew fatigue management is just as important to safe operations as other work disciplines.

By Peter Berendsen
ATP/CFII. Boeing 747, MD11

Bombardier Senior Capt Yann Lemasson demonstrates the Global Express XRS's crew rest area.

Recently I drove my car out of the garage of my company's flight operations building after an 8-day trip that took me to Germany, Kazakstan and Japan. While it was fun to drive home, I had the definite feeling that something was missing.

It had to do with my head and should have been located to the rear of me, maybe at the left window. I turned my head, searching, and then I realized that I was looking for my headset. After so many hours and days of flying, I was still in the cockpit, and my body wanted to drive my car like an airplane, with a headset on. I must have been very tired.

Pilot fatigue is almost as old as aviation, and as the performance of our beautiful flying machines allowed longer and longer flights, the human body had a hard time keeping up.

Charles Lindbergh wrote about his 1927 solo nonstop transatlantic flight to Paris, "My mind clicks on and off. I try letting one eyelid close at a time while I prop the other with my will. But the effect is too much, sleep is winning, my whole body argues dully that nothing, nothing life can attain is quite so desirable as sleep. My mind is losing resolution and control."

While the performance of Lindbergh's Spirit of St Louis left the famous aviator no choice but to operate alone across the ocean, commercial factors such as long duty days, crew rotations or the avoidance of layover and hotel costs may also contribute to pilot fatigue.

Of course, there are duty time rules-and operators and crews usually know them and abide by them. But in today's economic environment there is a constant pressure on cost, and, just like other safety-related matters, crew fatigue management comes with a cost and is increasingly hard to justify.

Operators look for ways to twist the rules or even change them. But even good intent can backfire, such as JetBlue's recent experiments with extended duty days. Volunteer line pilots wore devices, designed by Alertness Solutions in Cupertino CA, which measured their fitness and alertness. The tests targeted the inflexible domestic 8-hour rule and had only been approved by local FAA officials. When the Wall Street Journal reported on the tests on regular line flights, however, the public outcry quickly forced FAA headquarters to stop them.

Captains Peter Berendsen (L) and Werner Hamberger prepare their McDonnell Douglas MD11F freighter for an 0100 departure to NBO (Nairobi, Kenya). Commercial operational needs and human circadian rhythms are difficult to reconcile.

Congress has looked into pilot fatigue since the early 1980s. In a 1999 hearing before the Aviation Subcommittee of the US House of Representatives, NASA officials reported on the results of the fatigue countermeasures program conducted by NASA Ames Research Center and funded by Congress. The program was created to collect systematic, scientific information on fatigue, sleep, performance in flight operations and circadian rhythms-the biological "clock" that regulates the body's daily sleeping/waking patterns.

Scientists found that pilot fatigue is "a significant safety issue in aviation." The report continued, "Rather than simply being a mental state that can be willed away or overcome through motivation or discipline, fatigue is rooted in physiological mechanisms related to sleep, sleep loss and circadian rhythms."

The first time NTSB identified fatigue as a probable cause in an aviation accident was in the 1993 crash of a Kalitta Intl Douglas DC8-61 freighter in Guantanamo Bay, Cuba. NASA researchers worked with NTSB investigators and found that all 3 crewmembers had a severe cumulative sleep loss due to many continuous hours of wakefulness, and that their bodies had struggled with the circadian time of day-that is, their hormone and body chemistry levels. And, of course, they never got to fly the next sector that company ops had still planned for them.

It is safe to say that today's rules on crew rest-and it doesn't matter which FAR part you operate under-do not reflect the state of the art in fatigue and sleep research. The body's circadian rhythm is part of our biology. Night flights or transmeridian flights lead to a circadian desynchronization, followed by reduced performance and reaction times. Crew duty time rules do not generally mention the body clock, but they set the standard that pilots are expected to follow, and crews believe that they should be able to be well rested during a legal duty day/rest period sequence. And, if they feel tired, they blame their own lack of self-discipline and probably do not communicate their tiredness to their fellow crewmembers. Others cannot feel your fatigue, unless you've nodded off already.

Warning signs

Many of us have experienced the warning signs of fatigue. When you are tired, your eyes go in and out of focus, there is a persistent urge to yawn, routine flightdeck procedures are missed or performed incorrectly, and control accuracy degrades. And, of course, there is an unbearable desire to sleep.

While a nice nap seems to be the logical solution to sleepiness, this is not really legal in the US while performing duties as a flightcrew member, even though NASA recommends it (the so-called NASA nap). The agency's fatigue countermeasures program submitted a draft advisory circular to FAA in Jan 1993, entitled Controlled Rest on the Flight Deck.

Beechjet 400A pilots fly to IAD (Dulles, Washington DC) at night. A well-rested crew is essential for safe night-time flight, and office work prior to the flight should be out of the question.

Some foreign operators take advantage of NASA's research and permit naps in the cruise portion of the flight. Short "power" naps of 10-30 minutes can help restore alertness for 3-4 hours. However, it is important to remember that it takes a crewmember 20 minutes after awakening to become fully alert and functional before assuming aircrew duties.

NASA's study was conducted in aircraft with 3 flightdeck crewmembers. However, on a 2-crew flightdeck-and most airplanes are operated by 2 pilots these days-this napping policy makes the somewhat risky assumption that nothing critical will happen during the crewmember's napping period, or that the remaining single crewmember will be able to handle it if necessary.

To me, inflight napping sounds more like an emergency procedure, or at least the lesser of 2 evils. The other evil would be an unscheduled stop at an unfamiliar airport and the ensuing search for crew (and probably passenger) sleeping quarters.

While I can follow the argument that it is better to have a pilot nap in cruise flight than during the approach and landing phases of flight, it still seems to me that there are a lot of things that can be done to prevent fatigue before crews get to the last resort of inflight napping.



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