Fatigue is a factor
What is the most difficult word to say in the entire aviation lexicon? No.
That's it. The most difficult thing to say in aviation is "no."
The irony of the word "no" is that the more experienced and skilled we get as pilots, the more difficult it can be to say. When we are new and green at the flying thing with tentative confidence in our abilities, it's easy to say no. "No, the wind is just too strong to go today," or "The weather is kinda iffy--the briefer said it could go down to marginal VFR at the destination--so, no, I don't think I'll go."
Wind and weather aren't the only items on a new pilot's no-go list. Hostile terrain, night flying, something questionable about the airplane, reluctant passengers--the list is pretty extensive, and that is a good thing. It says that we are aware of our limitations, and make decisions accordingly.
Time, experience, and exposure to more situations lead to increased confidence. We learn the subtleties of the airplane's capabilities and limitations--and, more important, our own. We don't need to say no nearly as often because we are capable and confident of performing safely under a much wider range and variety of situations.
Experience also provides us with the tools to better analyze and anticipate problems much earlier in the flight-planning process so we can make adjustments to avoid no-go situations. For example, if I see a developing front that could affect the flight I'm planning in three days, I may decide to move the flight up a day to beat the weather.
One factor where experience may not be a big help in providing needed judgment is fatigue. Experience tells us that we've flown when tired before, and we can do it again. We drive when we're tired, we work when we're tired--heck, everyone is tired these days. If we said no to flying every time we felt tired, we wouldn't fly much.
That attitude is a particular problem among pilots because we are an aging population, and fatigue is partly a function of age. The older we are, the less we are able to compensate for fatigue. So for pilots fatigue can be a double-edge sword--as we gain experience in the cockpit we tend to discount the effects of fatigue on our piloting abilities. Although we may do more flying when fatigued, as we grow older we are less able to handle fatigue.
Lack of food or water, insufficient or interrupted sleep, sustained or concentrated physical or mental activity, stress, summer heat and humidity, advancing age--any of these conditions can result in a state of fatigue. Fatigue leads directly to impaired performance--forgetfulness, poor decision-making, slowed reaction time, reduced vigilance, poor communication, fixation, apathy, lethargy, a bad mood, and nodding off.
Fatigue may be easier to recognize in others than in ourselves. I remember hopping a ride back from an event with a friend who planned to fly home after dropping me off. It was already mid-afternoon when we landed. My friend was wrapping up a long, hot week on the road, and he looked and acted like he was on the verge of mild exhaustion. When he remarked that he hadn't eaten anything that day, I insisted he park the airplane and come with me. Thirty minutes and a sub sandwich later he perked up as if he had been jolted with a heart defibrillator.
In three decades of flying, much of it alone in the airplane, I think I've experienced every one of the signs and symptoms of fatigue. I've had to fight powerful urges to catnap. I've shaken my head to jump-start my brain. I've muffed requests to ATC, and been miffed at their instructions to me. While I believe I'm getting somewhat wiser as I grow somewhat older, I have to concede that I'm still capable of ignoring the power and potential of fatigue.
A few years ago I participated in an informal experiment having to do with fatigue and flying. Capt. Hank Butehorn, at the time a jet and helicopter pilot for a major U.S. drug company, had been on an aviation association committee that was looking into the issue of fatigue and its effect on pilots' abilities. He invited me to fly with him. The catch--we both were supposed to be dog-tired.
Obviously, this would have been a dumb and irresponsible thing to do in an actual airplane. That's why we met in Orlando at SimCom, a major simulator-based pilot training center.
Butehorn was anxious to spread the word to the private pilot community about the insidious nature of fatigue in flying. He and I each spent several hours flying two of SimCom's sophisticated visual simulators, the Pilatus PC-12 and the Piper PA-31-350 Navajo Chieftain. At the time I'd logged a few hours in a short-body Navajo, but had no previous experience in the big Pilatus turboprop single. Our SimCom instructors spared us from multiple engine and systems failures, but not from hand-flying precision approaches to absolute minimums.
We flew in the evening, earlier and less fatigued than we had hoped, and thus with a higher state of alertness and skill than we anticipated. Even so, I recognized signs of mild fatigue in my performance. My scan suffered, and as a result the plots of my approaches showed some wandering about. All performance bets would have been off if we had flown into the "window of circadian low," defined as the hours between 2 and 6 a.m. when the body's need for sleep is greatest.
Private pilots and professional corporate pilots operating under FAR Part 91 do not have to observe specific FAA-imposed flight and duty-time limits. But that freedom imposes a responsibility to self-regulate so that we avoid situations where fatigue may jeopardize safety of flight. The stereotype image of the hero pilot pushing on, Lindbergh-like, in the grip of extreme fatigue has no relevance in today's world.
Managing fatigue is a win-win endeavor because it encourages a healthy lifestyle. It means good sleeping habits; resting periodically; eating a balanced, healthy diet; drinking plenty of water (including at least eight ounces per hour of flight time); exercising regularly; and taking measures to stay alert and engaged while flying.
And you thought "checkride" was the hardest word to say in aviation.
Mark Twombly is a writer and editor who has been flying since 1968. He is a commercial pilot with instrument and multiengine ratings and flies a Piper Aztec.
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