Fatigue and the single pilot

June 1, 2000

My laptop computer and handheld electronic personal organizer have a distinct design advantage over their operator: Each sounds a warning when the battery charge wanes to a critically low state.

We pilots have no such definitive monitoring and annunciation feature to alert us to the imminent onset of a potentially dangerous low-power condition: 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 airshow with a friend who planned to fly home after dropping me off. It was already midafternoon 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 like he had been jolted with a heart defibrillator. And, in a way, he had.

In 33 years 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.

I had a day recently that actually began the night before, when I finally went to sleep at midnight after spending a couple of late hours in the home office. I slept fitfully, obsessing in the dark about work, then awoke for good at 5:30 a.m.

Some coffee, some stretching, and then it was back into the new blue office chair to pick up the ax and resume chipping away at the backlog of tasks. The deadline for wrapping up the office work was early afternoon because I had to fly to Orlando to make a 6:30 p.m. appointment.

My mission in Orlando was to be irresponsible, to fly while thumbing my nose at fatigue. The flying would be simulated, however, using the facilities of SimCom International Inc.

I was put up to the task by Capt. Hank Butehorn, a dual-rated jet and helicopter pilot for Pfizer who also sits on the National Business Aviation Association’s operations committee. The committee has produced a fatigue management program that provides corporate flight departments with the results of research on fatigue issues, as well as flight and duty-time recommendations developed by the Flight Safety Foundation (FSF). The recommendations are aimed at two- and three-pilot operations (a third pilot to relieve the primary crew on long international flights), and therefore don’t apply to the unstructured schedule and go-it-alone nature of an individual who flies single-cockpit. However, committee members are anxious to spread the word to the private pilot community about the insidious nature of fatigue in flying.

Hank 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. I’ve logged a few hours in a short-body Navajo, but have 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 a.m. 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.

Fly rested, fed, hydrated, and fit, and you’ll fly alert, positive, and safe.