Dirty Dozen: Fatigue

Even Charles Lindbergh recognized the imminent danger of fatigue.

"My mind clicks on and off,” he said of his trans-Atlantic flight. “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."

The desirability of sleep is something we all usually feel at some point during the work day. Loss of resolution and control, however, is the result of fatigue and can contribute directly to accidents.

In 1998, Bosley, Miller, and Watson completed a study of workplace factors and fatigue in aircraft maintenance environments. According to that study, “Each day aviation maintenance workers are sometimes faced with sub-optimal work conditions which contribute to fatigue. When these conditions can be controlled they must be. When such conditions cannot be controlled then the system must help the human to work in a manner that is safe, healthy, efficient, and effective.”

Causes and risks of fatigue
Fatigue is a feeling of tiredness, exhaustion, or lack of energy. Common causes of fatigue include lack of sleep, lack of exercise, stress, anxiety, poor health, overwork, worry, boredom, and disruption in circadian rhythm. Circadian rhythm is a daily rhythmic activity cycle, based on 24-hour intervals. Many of us have a routine of getting up at a certain time, working certain hours, eating at certain times, and going to bed around the same time daily. Any interruption to this could take us out of our groove and make it hard to adjust. Fatigue could also be a sign of anxiety or depression.

Maintenance workers studied by Bosley et al say that things like hangar noise, heat, humidity, inadequate lighting, and inadequate ventilation are factors that affect their work negatively. Of those, heat, humidity, and poor lighting and ventilation can relate directly to fatigue. Think about the last time you had to work in a hot hangar or workshop, and how everyday tasks seemed to take that much more out of you.

Working long shifts, split shifts, or inconsistent shifts can put someone at risk for fatigue. Constantly rearranging your sleep schedule can throw off your body’s natural rhythms and make it hard to adjust. Not getting enough sleep or rest between shifts can make your body that much more resistant to being awake.

Improving your diet and adding exercise to your regimen can help reduce your risk for fatigue. Cutting back on caffeine, alcohol, and nicotine can help as well.

The best way to combat fatigue is simply to get some sleep. However, this isn’t always as easy as it sounds.

Some ways to improve sleep include going to bed at the same time every night and cutting back on your television viewing to reduce stress on your eyes. Don’t eat right before bed. Don’t read or watch television in bed; this will help train your brain that your bed is only for sleeping in. If you do add exercise to your routine, don’t exercise within three hours of the time you go to bed – this gives your system time to readjust to its resting levels.

Symptoms of fatigue
Someone who is fatigued often exhibits reduced visual perception, short-term memory loss, distractibility, and loss of initiative. He or she will not be able to concentrate properly and likely will not notice that his or her performance has diminished. This person’s work might appear sloppy due to impaired decision making or judgment skills. The fatigued worker could also appear irritable or depressed.

The study by Bosley et al suggests that “airline maintenance workers do not perceive fatigue as a major problem.” However, decreased performance and sloppy work will not sit well with those who depend on the aircraft maintenance worker to be on top of their game. Sloppy work also puts air traveler safety at risk.

“I have been a lead mechanic for over 25 years for the airlines,” says a mechanic surveyed by the FAA. “Have I ever worked tired when I shouldn’t have or seen others who worked tired when they shouldn’t have? Yes. Do other mechanics, leads, and management know about it? Yes. Have mistakes been made due to fatigue? Yes.”

In the Bosley et al study, 84 percent of mechanics surveyed stated there should be a regulation regarding the length of duty time and rest for all maintenance personnel.

FAA Sec. 121.377 states that “Within the United States, each certificate holder (or person performing maintenance or preventive maintenance functions for it) shall relieve each person performing maintenance or preventive maintenance from duty for a period of at least 24 consecutive hours during any seven consecutive days, or the equivalent thereof within any one calendar month.”

Some mechanics feel this allows for their employers to overwork them during the time they are not required to have off. One mechanic surveyed by the FAA mentioned that it wasn’t unusual for him to have only three days off in 30.

“I am a corporate maintenance technician and I am basically on call 24 hours a day. When an aircraft is broken I must stay until it is repaired,” reads one testimonial in an FAA presentation from its 2008 Fatigue Conference. “My fatigue level, or lack of rest has never seemed to be a factor to the chief pilot(s). There has always been said and unsaid pressure to get the aircraft back in service. The pilots have always been concerned over their duty times. Many times I’ve worked when I felt I was too fatigued.”

Putting the issue to rest
The FAA held its first aviation fatigue symposium June 17-19, 2008, in order to bring together 325 industry, government, and academic minds to discuss possible fatigue management strategies and best practices. Many experts consider scientifically based fatigue risk management systems the key to addressing the problem of fatigue. Attendees emphasized the necessity for government and industry to develop a culture that does not penalize employees who stay away from work due to fatigue.

The National Transportation Safety Board ordered the study done by Bosley et al in 1989, yet fatigue remains on its 2009 “Most Wanted” list of safety improvements that was released in October of 2008. According to its documents, the NTSB “has long been concerned about the effects of fatigue on persons performing critical functions in all modes of transportation” because it presents unnecessary risk to the traveling public. To this day it recommends setting work hour limits based on fatigue research, circadian rhythms, and sleep rest requirements.

Following these recommendations is up to the employee as well as employer. The safety of the traveling public depends on it.

This is the first in a series of articles on the Dirty Dozen. The Dirty Dozen was developed by Gordon Dupont at Transport Canada. They are critical factors in the area of human factors and safety; they are complacency, lack of knowledge, lack of teamwork, distraction, fatigue, lack of resources, pressure, lack of assertiveness, lack of communication, norms, stress, and lack of awareness.