Asleep at the Yoke?
by Jennifer Caron, FAA Safety Briefing Copy Editor
“There is no sunrise so beautiful that it is worth waking me up to see it!”
— Mindy Kaling
Who doesn’t love a good night’s sleep? For me, a spur-of-the-moment nap on a lazy Saturday afternoon curled up under a soft, warm blanket is heavenly bliss. Sleep is, in fact, as necessary as food and water. Without it, we experience significant physical and psychological problems.
If you’ve ever been a new parent, a graveyard shift worker, or burdened by an untreated sleep disorder such as insomnia or sleep apnea, you know what it’s like to try and get through the day without enough sleep. You’re tired and out of sorts, it only takes a feather to push your buttons, and caffeine and sugar are your two best friends. It’s easy to rationalize and tell ourselves we don’t need sleep but if we don’t get enough of it, or if our sleep is interrupted, we will suffer from fatigue.
What is Fatigue?
We know it when we feel it. Fatigue is that drowsy, weary, sleepy feeling you get when you haven’t had enough rest. It’s an all too common part of our workaholic American culture, which is known for too much of the wrong food, too little of the right exercise, and insufficient or poor quality sleep.
But fatigue is not unique to our culture. It is a human condition that affects each and every one of us. No profession, activity, or gender is immune to its effects. Whether you’re a pilot, a truck driver, or a paramedic, if you’re sleep deprived you will experience the same physical and mental limitations across the board. What causes the fatigue is less important than the negative impact it has on your ability to perform tasks. Like drugs or alcohol, fatigue slows reaction time, decreases awareness, and impairs judgment.
Fatigue poses the highest risk during the task-critical taxi, takeoff, and landing phases.
For most, fatigue can easily be resolved with a nap or by “sleeping in” the next day, without any adverse effects. But if you are involved in safety-related aviation activities such as air traffic control (ATC), or piloting or maintaining an aircraft, the consequences of fatigue can be disastrous.
How Does Fatigue Affect GA?
While commercial pilots are more prone to the occupational fatigue that results from long duty days, schedule changes, or multiple time zones, GA pilots can develop fatigue too. The risk of accidents is higher due to the challenges of single-pilot operations and the relatively higher individual workload. Also, GA pilots don’t usually have the benefit of a second pilot to share tasks or to help judge fitness for flight. Research shows that humans are poor judges of their own fatigue level. Family, friends, and crew are a lot more honest — sometimes brutally! — and won’t hesitate to tell you how tired or ill you really look.
Fatigue impairs performance and has a negative impact on basic piloting skills.
“You are probably more fatigued than you think, and you pose a bigger threat to your safety than you realize,” says Dr. Katrina Avers, a research scientist in the Human Factors Research Division at the FAA’s Civil Aerospace Medical Institute (CAMI). Her research focuses on fatigue education and fatigue risk management programs for flight crew, cabin crew, and maintenance technicians.
“We think that if we just push through and focus hard enough then we can overcome it, or if we drink enough caffeine then our performance levels will improve. But that’s just not true,” says Dr. Avers. In the end, you’re still fatigued and your performance still suffers.
Motivation, caffeine, physical activity, and environmental stimulation can mask fatigue and possibly enable you to ignore the symptoms for a while. But they will not eliminate unavoidable physical effects. Coordination and alertness decline. Performance falls off, judgment and decision making become impaired, and you might take unwarranted risks. Even the most experienced pilots make mistakes when they’re flying fatigued, and no amount of masking can overcome its effects. “It’s much easier for us to look for risk factors in our flight environment than it is to look for those same risk factors in ourselves, but we have to be self-aware and recognize how impaired we really are to avoid flying fatigued,” Dr. Avers explains.
A particularly insidious fatigue risk takes the form of short sleep attacks, also known as micro-sleeps. These are brief periods of sleep where you nod off suddenly and without warning. According to a 2001 study of in-flight brain activity, “pilot micro-sleeps occurred most frequently during the middle-to-late segments of cruise flight. They were over nine times more likely during night flights. Despite strong motivation to be alert during the final stages of flight, micro-events were also found to occur during the period from top-of-descent to landing.” None of these are good things for a pilot, especially if there is no one else in the aircraft to help keep the pilot alert.
Fatigue is not only a risk during the lull of cruise flight. It poses the highest risk during the task-critical taxi, takeoff, and landing phases. Reported fatigue-related events have included procedural errors, unstable approaches, lining up with the wrong runway, runway incursions, landing without clearances, and poor decision making.
“Fatigue impairs your performance and can have a negative impact on even fundamental skills,” explains Dr. Avers. It compromises your ability to react quickly and communicate effectively. It adversely affects your memory and eye-hand coordination, so much so that after 17 hours without sleep, your ability to control, guide, and direct your hands closely resembles someone with a blood alcohol content of 0.05- to 0.08-percent.
To see the relationship between sleep and performance levels, take a look at the sleep restriction study in Figure 1. Results show that there’s an increase in your level of impairment when sleep is reduced below seven hours per night. “Simply put, as your sleep decreases, your risk of incidents and accidents increases,” says Dr. Avers. “The impacts of fatigue aren’t just when we pull an all-nighter,” she continues. “An individual that gets six hours of sleep per night over two weeks can have the same level of elevated fatigue as someone that has been awake for 24 hours straight.”
If you’re flying fatigued, another risk is how you will react to an in-flight emergency or any unexpected situation that causes intense periods of stress. One way to think about the role of fatigue in accident risk is to know that fatigue causes random episodes of inattention just when you need all of your attention to avoid an accident.
Like drugs or alcohol, fatigue slows reaction time, decreases awareness, and impairs judgment.
Consider the example of an in-flight engine failure. Your first priority is to remain calm, run through memory and checklist items, and look for a safe place to land. But here’s what could happen if you’re flying on an empty sleep tank. Reaction time slows, you’re not focused, and panic mounts as you waste precious time and altitude trying to make decisions. Your thinking is fuzzy, memory items fade, eye-hand coordination is off, situational awareness is affected, and you’re more likely to make errors and engage in risky behavior. As listening and communication skills diminish, it gets harder to find the right words for the mic. Any of these scenarios could greatly reduce the chances for a successful outcome.
Fatigue is of particular concern to aviation shift workers, including ATC and maintenance. It is a common belief that shift workers adapt over time and don’t experience fatigue. Not so. Shifted schedules require working against the body’s internal clock (circadian rhythm). Naturally regulated by light, the circadian rhythm tells you to be awake when it’s light and to go to sleep when it’s dark. Under these conditions, you are more vulnerable to fatigue because your sleep/wake cycle is out of sync. The result: degraded performance, increased errors, decreased morale, and other safety risks. Companies can regulate shift work and time off, but there is also an individual responsibility to monitor and control sleep habits.
So How Can You Combat Fatigue?
“The best way to combat fatigue is to improve your understanding of what causes it, know the risks associated with it, and apply effective countermeasures,” says Dr. Avers. You can take the FAA’s free fatigue training course on FAASafety.gov. Created by the FAA’s Human Factors Research Division and the FAA Safety Team (FAASTeam), over 500,000 pilots and mechanics have taken the course. Here’s a link to get you started: bit.ly/FAAFatigueTraining. To learn more about managing fatigue and to try out the fatigue risk assessment tool visit bit.ly/FatigueMgmt. Here’s a fact sheet that shows how the FAA is addressing some fatigue issues called out by the National Transportation Safety Board: bit.ly/FAAFactSheet.
A few more tips:
- Identify Fatigue: If you feel the urge to doze every time you sit down, you are likely fatigued. Look for these symptoms: yawning, nodding off, attention lapses, difficulty concentrating, and irritability. Use the IMSAFE checklist to check your health before engaging in any aviation-related activities.
- Manage Fatigue: If you feel fatigued, ground yourself until you can get sufficient rest. Remember that caffeine only masks fatigue and is not a substitute for sleep! Nap strategically; some sleep is better than none. Even a 10-minute nap can help, but do not use cat naps to replace a good night’s sleep.
- Prevent Fatigue: Establish good sleeping habits and stick to the routine. You can find a sleep log to track your sleep, and many more fatigue countermeasures, at mxfatigue.com.
Jennifer Caron is FAA Safety Briefing’s copy editor and quality assurance lead. She is a certified technical writer-editor in aviation safety and flight standards.