Helicopters Magazine

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The Fatigue Factor

July 30, 2013  By Paul Dixon

When was the last time you showed up at work drunk? OK, allow me to rephrase the question.

When was the last time you showed up at work drunk? OK, allow me to rephrase the question. When was the last time you showed up at work so tired that your mental and physical abilities were impaired to a level equal to a 0.08 blood alcohol level?

Research has shown that being awake for 18 hours produces a level of impairment equal to a blood alcohol level of 0.05 and after 24 hours a blood alcohol level equal to 0.10. That’s just from being awake, after a good night’s sleep, without adding in physical exertion or the stresses of your day-to-day existence.

Aviation technology and operational demands have grown exponentially over the past 60 years, yet our human need for sleep remains unchanged as we have evolved from our humble beginnings more than four million years ago. Fatigue degrades most aspects of performance, leading to lapsing, cognitive slowing, memory impairment and decreased vigilance. Sleep-deprived people are more irritable, forgetful and averse to effort. Pilots may lose the ability to perceive and integrate important information due to tunnel vision, a potential effect of sleep deprivation. Performance becomes less consistent and the ability to follow procedures diminishes.

Years ago, I taught a course at the RCMP Fairmont Academy in Vancouver. If we were lucky, there would be a breathalyzer course being run in the building at the same time. Part of the breathalyzer course is familiarizing the young police officers with identifying the physical symptoms of alcohol impairment. For class purposes, this was achieved by having half the class show up without having eaten any breakfast. An empty stomach, coupled with the carefully controlled ingestion of alcohol, would result in reliable blood alcohol levels for observation, with physical tests being conducted before the next shot was downed. To the casual observer, it was always interesting to see just how a small amount of alcohol could wreak so much havoc on those earnest young police officers. With any luck, there’d be at least one fist fight by 10 a.m. and a whole lot of yelling and arguing for the rest of the day.


Such information is food for thought. The young Mounties were being taken through that first level of 0.05 and then up through 0.10 and not too far beyond. It was just enough to make them legally impaired, yet it often turned into a gong show. Alcohol does tend to bring out a level of aggression that rarely happens with sleep deprivation, but when it comes to the ability (or willingness) to process information and follow instructions, that’s where we see the strong correlation.

If you’ve been to the CHC Safety & Quality Summit, you’ve likely heard Scott Shappell talk about recognizing and managing fatigue in aviation, as well has his very lively “Spin and Puke” workshop on the effects of alcohol on the mysteries of the inner ear. This year’s Summit saw Michael Paul, a research scientist with Defence Research and Development Canada, talk about his work with RCAF CC-130 crews, as well as RCN submarine crews, in terms of assessing fatigue levels when crews are forced to operate outside their usual environments.

CC-130 crews providing airlift support to Canadian operations in Bosnia and then Afghanistan were forced to fly long hours in transit and then operate in theatre on a clock that was up to nine hours different from their home base. Submarine crews at sea work a series of rotating shifts to maintain a 24/7 operational and tactical capacity. For both the aircrews and the submariners, Paul’s research demonstrated that the time shifting coupled with the operational tempo of their missions took them through the levels of physical impairment equal to the blood alcohol levels noted previously and often they went further, delving into an area he describes only as “clinical stupidity.” A program was devised that recognized the causal factors, leading to policy changes that both allow for and enable more rest.

Historically, fatigue has not been listed a prime causal factor in aviation accident investigations, but in recent years it is now being considered. Since retiring, Capt. Chesley “Sully” Sullenberger has been a leading advocate for increased awareness of the perils of flying when fatigued. Asked by ABC News if he would have been able to put Flight 1549 in the Hudson if he had not been rested on that day, he responded most emphatically, “probably not.”

Doing the right thing at the right time, all the time, doesn’t just apply to the pilots in your organization – it applies to everyone. It’s taken us a long time to get serious about alcohol and flying and it’s a good thing that we have. Now, we need to work on getting a good night’s sleep.

Paul Dixon is freelance writer and photojournalist living in Vancouver.


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