Humans, by our very nature, are daytime creatures. Our brains and our bodies have been hardwired for this, and not even the fairly recent (in evolutionary terms) innovation of artificial light can change hundreds of thousands of years of development. In response to darkness, our brains produce a chemical known as melatonin, which makes us sleepy, yet these days we are far removed from the agrarian “get up when it’s light out, go to bed when it’s dark” lifestyle of just a few centuries ago.
With today’s 24/7 pace, most people are fatigued to some degree. In fact, a recent study found that people most commonly trade sleep to make time for other activities. The result is fatigue and degraded response time and decision-making. For people in high-skill occupations such as pilots, such decreases can lead to catastrophic results. The inquest into the 2009 crash of Air France Flight 447 into the Atlantic during a flight from Brazil to France discovered that the pilot admitted in a conversation captured on the cockpit voice recorder that he had had only one hour of sleep the night before the flight. That same year, questions were raised about how much the pilots of Colgan Air Flight 3407 had slept before the regional turboprop crashed near Buffalo, N.Y.
While it is genetically determined whether we are “morning people” or “evening people,” disregarding the body’s internal clock–either through extended periods of wakefulness or through the effects of rapid time zone hopping made possible by jet aircraft–can result in fatigue, defined by the International Civil Aviation Organization as a physiological state of reduced mental or physical performance capability resulting from sleep loss or extended wakefulness, circadian phase or workload (mental and/or physical activity) that can impair a crewmember’s alertness and ability to safely operate an aircraft or perform safety-related duties.
Managing fatigue was the focus of a recent series of NBAA-sponsored seminars at Morristown Municipal Airport (MMU) in New Jersey; Igor I. Sikorsky Memorial Airport (BDR) in Stratford, Conn.; and Bentley College in Waltham, Mass. “Sleep is important,” said presenter Dr. Melissa Mallis, a sleep researcher and chief scientific advisor for California-based fatigue management solutions provider Alertness Solutions. “It’s as important as nutrition and hydration.” Nonetheless, myths regarding fatigue persist: it’s a sign of weakness; it can be overcome with coffee and willpower. “It’s not that you’ve pushed through it before, it’s not because you have the ‘right stuff’; there’s actually a clock in your brain that controls the amount of sleep you get and your periods of maximum alertness and sleepiness,” Mallis told the audience gathered in the Volo Aviation hangar at BDR.
Alertness Solutions’ training de-personalizes the effects of individual fatigue, concentrating instead on its overall physiological aspects. The company advises pilots to make sleep a priority, both in their daily regimen and especially when preparing for a long-distance flight. Studies have shown that those people who are “evening people” by nature typically have an easier time adapting to changes in schedule or time zone.
While people in general need seven to nine hours of sleep a night, it is typical for work and other commitments to limit actual sleep to five or six hours. Hours of sleep loss are cumulative, so over the course of a workweek, an individual could lose almost an entire night’s sleep. Also, if an individual is awake for more than 16 hours or so at a stretch, performance levels decline drastically toward the end of that period, with reduced coordination, difficulty maintaining attention, fixation, impaired problem solving and increased risk-taking behavior all threatening safety.
While it may be difficult to medically quantify sleepiness, tools such as the psychomotor vigilance test measure reactions to visual stimuli in milliseconds, giving researchers an indication of its effects.
Mallis noted that fatigue is affected primarily by four factors: the amount and quality of recent sleep, how long it has been since the last sleep period, the time of day, and time on task. Circadian rhythm, the body clock that governs our functioning, produces periods in the 24-hour cycle during which we are at low points of alertness (window of circadian low or WOCL), typically between 3 a.m. and 5 a.m. and 3 p.m. and 5 p.m. (the oft-experienced afternoon lull). During long-distance flights, pilots may often find themselves operating during those times and should plan to take steps to mitigate the effects.
Managing Fatigue: Proactive Versus Reactive
Successful fatigue management depends upon a partnership between the individual and the organization. Pilots are expected to make sure they are rested to perform their duties and to notify their superiors if they believe they are not. Flight departments are responsible for creating schedules that consider pilot duty limits and rest requirements.
Current Part 91 operations are based on guidelines first published in 1997 by the FlightSafety Foundation. Alertness Solutions has recently received funding from NBAA to update those guidelines, and it plans to hold an open meeting at the annual NBAA Convention in October to solicit feedback before those new policies are published early next year. The company is also working with IBAC to improve IS-BAO guidelines to make fatigue awareness in safety management systems more comprehensive and more easily auditable.
Fatigue education should be given to everyone who fills a mission-critical role, not just pilots and cabin crew but also schedulers and dispatchers, maintenance technicians and managers. Such training needs to be annual, according to Alertness Solutions president Leigh White, who described it as an essential part of a safety culture that includes duty limits and rest guidelines, scheduling policies, fatigue reporting and the use of assessment tools such as flight risk assessment tool (Frat), a checklist available on NBAA’s website. Last year the FAA published its airline crew rest final rules under FAA Part 117. Captain Jim Mangie, director of Delta Air Lines’ pilot fatigue program, told the audience that business aviation operators should use those science-based guidelines as a framework for their own scheduling. “Is what you are trying to do right now legal under [Part] 117 and if it’s not, why not?” he asked. Flight departments can use Part 117 for a “gap analysis” to show companies what they are and should be doing to mitigate pilot fatigue.
A degree of planning is required to get pilots the appropriate rest before, during and after the flight. A layover plan is necessary to identify protected periods of rest for the crew. Such a plan must be realistic, considering such crew needs as meals, exercise and socializing. “Social factors count,” said Mangie. “As we gathered data through different operations we found that in Mumbai, on a 48-hour layover we were getting about 19 hours of sleep, but in Dubai about 10 hours. Same part of the world, same time of day. Lots to do in Dubai, not much to do in Mumbai.” Computer-based tools such as Safe (system for aircrew fatigue evaluation) allow schedulers to input flight plans that will outline periods of WOCL for the crew, based on their home time zone, making it possible to schedule around them and block out periods for rest. For those periods, individuals should take steps to create a restful environment, minimizing exposure to light by closing shades and wearing eye masks. The use of technology, such as PDAs, tablet computers or smartphones, in bed should be eliminated. Pilots can bring their own alarm clocks to provide peace of mind that they will wake when they are required.
The Alert Crew
“We’re not talking about eliminating fatigue; that’s unrealistic,” said White. “But we can do a lot to mitigate it and manage it.” At NBAA’s annual meeting last year, the association debuted The Alert Crew, a handbook prepared by Alertness Solutions (available upon request from NBAA), explaining the causes of fatigue among flight crews and strategies for combatting it. Suggestions include napping when possible, taking advantage of WOCL periods when sleep is easiest to achieve, but leaving at least 15 minutes of “wake-up” time after. Some rely on caffeine, which can be useful at certain times. The guide suggests that individuals use the stimulant before they expect to be tired, rather than wait until they are to consume it. The handbook has a chart showing the quantity of caffeine in various foods and beverages. The more caffeine you ingest daily, the less effective it will be. The presenters cautioned, however, that consolidated sleep is the only real way to reverse fatigue. Some aviation insurance providers have partnered with Alertness Solutions to provide fatigue management training to their customers through the company’s online Z-Coach program, which creates personal profiles charting sleep habits and needs.
One final note, crews often overlook the drive home at trip’s end. If you have been awake for more than 17 hours after several days of duty, make sure you calculate the total hours of wakefulness until you get home to decide if you need a nap before turning the key.
Don’t Fly Tired
During her research with NASA and other organizations, Dr. Melissa Mallis, a sleep researcher and chief scientific advisor for California-based fatigue management solutions provider Alertness Solutions, has learned that people’s perception of sleepiness does not typically match their objective performance. Studies show that people with two hours less sleep than the seven to nine hours required show the same degradation as someone with a blood alcohol content (BAC) of .05 percent; those with a four-hour deficit exhibit the effects similar to a .10 percent BAC (which is above the threshold for legal impairment in the U.S.).
Those numbers should give tired pilots pause when they are about to assume the controls of a multimillion-dollar business aircraft. “You are not always aware of how fatigued you are,” she said. “Just like when you are intoxicated due to alcohol…that’s how you are when you are sleepy, and your estimates are often a lot better than your performance is.”