Flight News On How To Easy on Fatigue To Enhance Safety In The Skies Unfortunately fatigue is everywhere and unavoidable in aviation. Pilot fatigue is a significant problem in modern aviation operations, largely because of the unpredictable work hours, long duty periods, circadian disruptions and insufficient sleep that are commonplace in civilian flight operations.
The full impact of fatigue is often underappreciated, but many of its harmful effects have long been known. Compared to people who are well-rested, people who are sleep deprived think and move more slowly, make more mistakes, and have memory difficulties. These negative effects may and do lead to aviation errors and accidents.
A position paper adopted by a panel of the Aerospace Medical Association (AsMA) said that accident statistics, pilot reports and operational flight studies all indicate that aviation operators are increasingly concerned about fatigue.
"On long haul flights pilots attribute their fatigue to sleep deprivation and circadian disturbances associated with time zone transitions", the fatigue panel said."Short haul (domestic) pilots most frequently blame their fatigue on sleep deprivation and high workload. Both long- and short haul pilots commonly associate their fatigue with nigh flights, jet lag, early wakeups, time pressure, multiple flight legs and consecutive duty periods without sufficient recovery breaks".
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Fatigue can negatively impact a crews response time, decision making and crew co-ordination. The aviation regulators have traditionally imposed hours-of-service limits governing how long and how often pilots can operate an airplane and this can minimize fatigue-related errors and accidents. Though each country has different limits imposed, but they are usually based upon very little, if any, scientific knowledge. It is only the Federal Aviation Administration (FAA) and the European Aviation Safety Agency (EASA) regulations governing flight time limitations are no different.
They mostly lack a sound scientific basis and have remained essentially unchanged for the last fifty years. While this regulations have undoubtedly save many lives, they are a fairly "blunt instrument" for managing the safety risk posed by fatigue. The traditional prescriptive HOS (Hours of Service) approach most likely derives from earlier regulatory models for managing physical rather than mental, fatigue.Prescription of duty limitations may have been appropriate for physical fatigue, the same cannot be assumed for mental fatigue.
Accidents continue to occur in which fatigue is cited as a significant contributor. According to some sources, fatigue is a contributing factor in 15 to 20 % of fatal aviation accidents associated with pilot error. While several unsuccessful attempts have been made to update the regulations, such efforts can best be described as "tweaking" what already exists and would likely result in little improvement. As an example, many regulatory regimes around the world do not recognize any difference between eight hours of duty time during the day and eight hours at night.
Flight surgeon Gregg Bendrick of the U.S National Aeronautics and Space Administration (NASA) teaches that there are three aspects of fatigue: circadian rhythm, acute sleep loss and chronic sleep loss. Circadian rhythm means that people have "low points" in their day in terms of alertness and functionality. A mild low point is normally in the mid-to late afternoon, whereas the other, more significant major low point in the early morning-when one normally is sleeping .Circadian rhythm physiology makes it easier for humans to lengthen their day rather than to shorten it.
A cute sleep loss refers to how many hours one has been continuously awake. The real problem comes in when the acute sleep loss overlaps the major low point in the circadian rhythm. At the point, performance deteriorates to the point of being identical to someone who is legally drunk.
Chronic sleep loss-the difference between the number of hours slept and the number of hours of sleep required-over the preceding two weeks lessens the effect of the usual counter measures.
The shift away from the blunt instrument of only limiting hours of sleep has become known as fatigue risk management (FRM) .FRM is fatigue management within the framework of a safety management system (SMS) .According to Dawson & McCulloch of the university of South Australia Centre for sleep Research, within an SMS framework, five levels should be considered in managing fatigue risk.
. Sleep opportunity or average sleep obtained across the organization
. Actual sleep obtained by individual employees
.Presence of fatigue related behavior
. Occurrence of fatigue related errors and
. Occurrence of fatigue related accident and/or accident
In this context, a fatigue related incident (FRI) is merely the end point of a causal chain of events and is always preceded by a common sequence of event classification that lead to the actual incident, according to Dawson& McCulloch.Thus an FRI is always preceded by a fatigue related error (FRE).
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A FRM system can be effective only if it addresses each of the five levels with organized defence systems.
For example, limits on crew members hours of service would be-according to figure 1-a Level 1 defense designed as an opportunity for sufficient sleep. If the crew member did not receive adequate sleep, the error trajectory would continue beyond Level 1. A system with little or no hazard controls at Level 2 or beyond may be quite poorly defended against FREs.
Defenses in –Depth Approach to Managing Fatigue
Hazard Assessment Error Trajectory Control Mechanism
Sleep opportunity/ Level 1 Prescriptive hours of service Aggregate prior
Average sleep obtained Sleep-wake model Fatigue modeling
Actual sleep Obtained Level 2 Prior sleep and wake data
Behavioral Symptoms Level 3 Symptoms checklists, self-report behavioral
Scales Physiological monitoring
Fatigue-related errors Level 4 Fatigue proofing strategies SMS
Error analysis system
Fatigue-related incidents SMS incident analysis system
Level 5
Actual Incident
A reduction in sleep during the 24-hours preceding flight is the fatigue –related variable most consistently associated with changes in crew performance. Dawson & McCulloch said "Crew take longer to make decisions if they have obtained a small opportunity to sleep(based on recent duty history) ,have obtained a small amount of sleep in the prior 24 hours or are experiencing high levels of subjective fatigue" . Taking longer to make decisions may have negative implications for operational safety, as this could lead to greater time pressures, which may enhance the risk of errors during the later stage of flight. The study also found several areas, such as improved performance, perhaps because fatigued crews anticipated errors and "devoted more cognitive resources and targeted behavioral strategies towards the detection of fatigue-related error". Cognitive refers to ability of a person to process information, apply knowledge and change preferences.
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In a 1999 NASA survey 80 % of 1424 flight crew members from regional airlines said they had nodded off during a flight. The AsMA fatigue panel reviewed several in-flight fatigue counter measures including napping on the flight deck, activity breaks, bunk sleep on long-haul flights and in-flight roistering.
According to the panel, in-seat napping of up to 40 or 45 minutes is a safe and effective risk management tool that could "significantly improve alertness…and help sustain aircrew performance during situations in which unexpected delays require the postponement of the next consolidates sleep opportunity.
Research has also found that alertness is improved with breaks for mild physical activity and increased social interaction "or eve just temporary disengagement from monotonous tasks with the AsMA panel recommending breaks of about 10 minutes each hour.
Crew members should also understand how their intake of caffeine-in coffee, tea, soft drinks and some pain relievers-will affect their alertness."Numerous studies have shown that caffeine increases vigilance and improves performance in sleep-deprived individuals, especially those who do not consume high does "the AsMA panel said."Caffeine…is already used as an alertness-enhancing substance in a variety of civil and military flight operations and it has proven safe and effective".
Most people feel the effects of caffeine-including increased alertness, decreased sleepiness and a more rapid heartbeat-within 15 to 20 minutes and these effects typically last four or five hours, longer in people who are especially sensitive. Crew members who use caffeine for alertness should consume it in small quantities, "and save the arousal effect until they really need it," the panel said."This is called 'tactical caffeine use" .The panel recommended that crew members avoid taking more than 1,000mg of caffeine in any 24-hour period, take it only "when it is truly needed to reduce the impact of fatigue "and avoid it within four hours of bedtime.
In the last few years, the aviation industry has also begun to study flight attendant fatigue. Recent and planned flight attendant fatigue studies include participants completing sleep diaries to verify sleep/wake schedules. In reports around the world, flight attendants have admitted that due to fatigue they had forgotten to arm their evacuation slides or had forgotten they had unaccompanied minors on board and allowed them to leave the aircraft by themselves. In some instances, flight attendants have reported being stopped by the police when driving due to the fact that police believed they were driving under influence of alcohol because of their erratic driving. Just prior to that the would have, by the regulators account ,been okay to operate the emergency equipment on board an aircraft in a fatigued fashion.However,as a fatigued driver on the road they are hazard to others.
Flight attendants still have to jump through hoops to say "I'm fatigued' to their airline without disciplinary consequences," said Candace Kolander during the February 2009 Cabin Safety Symposium of the Southern California Safety Institute. It is important to allow flight attendants call in fatigued without discipline but also organize and mitigate the problem by providing fatigue training in recurrent training.
If airlines want to have a complete SMS, they can't just look at fatigue in the front of the airplane, they need to look at fatigue in the back as well as amongst maintenance personnel .These subjects will be addressed in more detail in a future issue of Safety Focus.
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Crew Members should be educated about proper sleep hygiene. All in all, the individual pilot, scheduler and management must be convinced that sleep and circadian rhythms are important and that quality day-to-day sleep is the best possible protection against on-the-job fatigue according to the AsMA panel. Educational efforts should emphasize five points, the panel said:
. Fatigue is a physiological problem that cannot be overcome by motivation, training or willpower:
. People cannot reliably self-judge their own level of fatigue-related impairment:
. There are wide individual differences in fatigue susceptibility that must be taken into account but which presently cannot be reliably predicted:
.There is no one-size-fits-all 'magic bullet' (other than adequate sleep) that can counter fatigue for every person in every situation: but
. There are valid counter-fatigue strategies that will enhance safety and productivity, but only when they are correctly applied.
Fatigue represents a significant risk in aviation when left uaddressed.Below find a number of strategies provided and that can be employed to increase safety by reducing the risk of fatigue.
Recommendated to optimize sleep opportunities
. Wake up and go to bed about the same time every day.
.Use the sleep area only for sleep-not for everyday jobs.
. Establish a consistent bedtime routine-for example, read and take a hot shower, then go to bed.
.Perform aerobic exercises every day but not within two hours of bedtime.
.Keep the sleep area dark, quite, comfortable and relatively cool.
. Move the alarm clock out of sight.
. Avoid caffeine in the afternoon and evening.
. Avoid using alcohol to promote sleep.
.Avoid cigarettes, especially before bedtime.
.If you can't sleep, leave the sleep area and do something relaxing. When you become sleepy, go back to bed.
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. When rotating onto night shift duty, avoid morning sunlight.
. To promote daytime sleep, keep the sleep area dark and cool: use eye masks and either earplugs or a "masking boise" to limit interference from light and noise.
. Comply with the "recommendations to optimize sleep opportunities" above, with adjustments for daytime sleep. Before night duty, take a short nap.
.After waking from daytime sleep exposes you to at least two hours of sunlight or artificial bright light in the late afternoon or early evening.
If you compile what has been said and recommended you will be able to manage fatigue especially employers and the management team in all sectors in the economy and in particular aviation industry.
