LECTURE 5 JET LAG & FATIGUE IN AVIATION AVIATION HUMAN FACTOR

JET LAG

 Jet lag is a temporary disorder that causes fatigue, insomnia, and other symptoms as a result of air travel across time zones.  Jet Lag only occurs when flying from East-West or from West to East.  In other words when we change time zones.

 Traveling from west to east shortens the day.  Whereas from east to west travel lengthens the day.  Jet Lag does not occur form North-South and vice versa because there are no time zones changes. JET LAG

Jet Lag Jet lag is more evident if you fly from west to east because it is more difficult for your body to adjust to your “losing time”.

Why does jet lag occur?  The cause of jet lag is the inability of the body of a traveler to immediately adjust to the time in a different zone.  Thus, when a New Yorker arrives in Paris at midnight Paris time, his or her body continues to operate on New York time.

 As the body struggles to cope with the new schedule, temporary insomnia, fatigue, irritability, and an impaired ability to concentrate may set in.  The changed bathroom schedule may cause constipation or diarrhea.  The brain may become confused and disoriented as it attempts to cope with schedules. Why does jet lag occur?

How jetlag can affect the pilots  Jet lag causes circadian (body clock) changes conflict with the destination’s sunlight & activities.  Due to that, a jet lag sufferer (pilot/crew/passengers) may experience poor sleep, fatigue, insomnia, headache, constipation, confusion, dehydration, and even memory loss.  All these symptoms may reduce the pilot’s performance ( judgment, decision making)  Thus, jetlag also directly will affect the flight safety.

Tips to Help Minimize Jet Lag  Adjust your bedtime by an hour a day a few days before your trip to match the sleep schedule you will keep at your destination.  Reset your watch to the destination time to help you adjust more quickly to your destination time zone.  Drink plenty of water during your flight to avoid dehydration. Dehydration can make jet lag worse.

 Eat lightly but strategically.  What you eat can have a direct influence on your wake/sleep cycle.  Relax on the first day at your destination.  Give yourself a break and let your body adjust to the time change a little more gradually. Tips to Help Minimize Jet Lag

Fatigue Fatigue can be defines as extreme tiredness resulting from mental or physical illness.

Fatigue  Fatigue is noted by aviation community for many years as having a strong impact on flight safety and efficiency.  As length of fatigue increases, performance may decrease, consequently lead to aircraft mishaps.

Types of Fatigue  There are TWO types of fatigue which are:  Acute Fatigue short duration, recovered with good nights sleep.  Chronic Fatigue occurs over a period long period of time, long recovery!

Acute fatigue  Acute fatigue  Results from repeating tasks during long flights or from numerous repetitive short flights  Very common  Healthy persons recover with rest / sleep  Symptoms Tiredness Lack of Energy Loss of coordination Inattention to details

Chronic fatigue  Chronic fatigue  Occurs when recovery time is insufficient  Overlapping with factors of acute fatigue

Causes of Fatigue  Lack of Restful Sleep  Unable to allow sleep to take over.  Works too hard  Body used up great deal of Energy.  Dehydration  Body lose a large amount of water.  Caffeine  Too much caffeine keeps the body in a high degree of alertness, even to the point of being tense (unable to relax).

Causes of Fatigue  Long hours of working.  High intensity of stress  Large temperature variations.  Noise and Vibration for long periods.  STRONG lighting.

Symptoms of Fatigue  Attention & concentration reduced  take longer time for make decision making.  Short memory loss  quickly forgot command given by ATC.  Fixation  focus one thing only, ignore other important.  Feel or appear careless, uncoordinated, & confused  Impaired communication & cooperation

Prevention of Fatigue 20  Get adequate sleep  Maintain consistent schedules of sleep, daylight exposure, and naps.  Control sleeping environment  Sleep in darkness.  Control noise.  Control room temperature.  Napping  Practice good nutrition

 Lack of adequate sleeps and rest results in sleepy and fatigued pilots.  Air crash research revealed that the unsafe and dangerous situations can result from a crew that has not had adequate sleep.  This is because, not enough sleep lead to harder to pay attention, slower reaction times, poorer coordination & confusion. Fatigue Prevention - Sleep

 In other words, lose sleep or disrupt the body clock, will impair every aspect of human performance  Examples:  Judgment and decision making can be degraded by 50 percent and memory can be degraded 20 percent by sleep loss  Pilot must know that sleep is important as the body muscles and brain can only recover by sleep.  Beside that, sleep functions to rest mental & physical condition with gather again the new energy. Fatigue Prevention - Sleep

 The important is not the amount of the sleep but the quality of sleep.  After 6 to 8 hours working, they need to restore back their energy in about 7.5 hours of sleeping.  So that, they are thinking well and highly focus during their work.  If they are not having enough sleep well, they can cover it by take some napping. Fatigue Prevention - Sleep

Fatigue Prevention - Napping  When sleep is not available or shortened by operational concerns, combat naps are an alternative.  Napping is a good strategy for coping with sleep deprivation during continuous operations or other times when it is difficult to get a good night’s sleep.  Even naps as short as 10 min are good to prevent the individual feeling more tired.

Factors affecting sleep quality  Comfortable condition (noisy rooms, temperature, lighting)  Alcohol and caffeine consumptions  Time of sleep (too long or too short), this will disrupt the normal sleep circadian rhythm & cycle.  Circadian changes can affect sleep, especially when you are trying to sleep at times your body is not ready for sleep.

Factors affecting sleep quality  Our sleep/wake cycle is closely tied to our body temperature.  The duration and “quality” of sleep is dependent upon body temperature.  The important is the timing and quality of sleep, not the amount of sleep.

Conclusion  Total prevention of jet lag and fatigue are impossible, but its effects can be significantly moderated.  No Jet-Lag pills also is another method to reduce the effect of jet lag and fatigue.  As jet lag and fatigue can affect human performance, aviators should not take these problem lightly as it can endanger passenger life.  As passenger, we should have awareness towards jet lag and fatigue as it could threaten our life if prevention action is being neglected.