1. Lecture 10: Sleep, Jet Lag & Fatigue in Aviation
Aviation Human Factor
Lecture 10: Sleep, Jet Lag & Fatigue in Aviation

2. SLEEP

3. Sleep What is it?
“The natural periodic suspension of consciousness during which the powers of the body are restored.”
How does this definition compare to what the students already know?
MedlinePlus Medical Dictionary

4. How much sleep do you really need?
Sleep requirements vary dramatically among individuals (age and gender)
Newborns sleep as much as 20 hours/day
Children sleep 8-14 hours/day
Elderly sleep 6.5 hours/day
A minimum of 5 hours of uninterrupted “core” sleep is enough.
Sleeping in excess of 10 hours may produce sleep habit.
Varies in relation to age and gender
Newborns sleep as much as 20 hours/day
Children sleep 8-14 hours/day
Elderly sleep 6.5 hours/day
Women past age 35 sleep more than men

5. When determining sleep requirements, 3 main factors should be considered.
The complexity of the job to be performed. The more complex the task to be performed, the more sleep required for the individual to execute the task
The potential for loss from errors due to fatigue. Pilots require rest plans since flying is a dangerous endeavor with high potential for loss of life and high-tech equipment.
The individual’s ability to function with little sleep must also be taken into account, since this ability varies from person to person.
The complexity of the job to be performed. The more complex the task to be performed, the more sleep required for the individual to execute the task. For example, flying duties involve a great deal of attention, concentration, and rapid decision-making and therefore require much more rest to perform than manual labor tasks, like digging fighting positions, that are not challenging intellectually.
A second factor to be considered is the potential for loss from errors due to fatigue. Aviators require strict crew rest plans since flying is a dangerous endeavor with high potential for loss of life and high-tech equipment.
The individual’s ability to function with little sleep must also be taken into account, since this ability varies from person to person.

6. 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.
Essentially, as humans we're programmed to be asleep during the night and to be awake during the day. As soon as you reverse that, you literally have to override your biological program to be asleep to get your job done.
So there's a double whammy. One is you're trying to fly when you should be asleep. We know that's the lowest point of performance. The double whammy is that not only is your performance low at night, but also later you're trying to sleep during the day when your body is saying, "You should be awake." So the quality of sleep is less than it would be at night.
It doesn't matter what environment you look at. The most incidents and accidents will occur during 3-5 a.m. Even single car accidents, when no one else is on the road and no alcohol is involved. Between the 3-5 a.m. window is when the most accidents will happen.

7. 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.
Essentially, as humans we're programmed to be asleep during the night and to be awake during the day. As soon as you reverse that, you literally have to override your biological program to be asleep to get your job done.
So there's a double whammy. One is you're trying to fly when you should be asleep. We know that's the lowest point of performance. The double whammy is that not only is your performance low at night, but also later you're trying to sleep during the day when your body is saying, "You should be awake." So the quality of sleep is less than it would be at night.
It doesn't matter what environment you look at. The most incidents and accidents will occur during 3-5 a.m. Even single car accidents, when no one else is on the road and no alcohol is involved. Between the 3-5 a.m. window is when the most accidents will happen.

8. Circadian rhythms
“Circadian rhythms” means 24 hours cycle in the biochemical and physiological process of humans.
It also described as an internal biological clock that regulates our body functions, based on our wake/sleep cycle.
It is important in determining sleep cycles, hormone production, cell regeneration, and other biological activities.
A circadian rhythm is a roughly 24-hour cycle in the biochemical, physiological or behavioural processes of human. The term "circadian", coined by Franz Halberg,[1] comes from the Latin circa, "around", and diem or dies, "day", meaning literally "approximately one day". The formal study of biological temporal rhythms such as daily, tidal, weekly, seasonal, and annual rhythms, is called chronobiology.
Any time that our normal 25-hour circadian rhythm is interrupted, it will have physiological and behavioral impacts.
CRD will occurred if there is changes in sleep pattern, early-morning awakenings, and increased need for daytime napping.

9. Human Performance 12 am 12 noon 12 am 3 - 5 am 3 - 5 pm + _
Generally, the lowest performance, alertness, and mood occur twice a day: from 3 am to 5 am, and to a lesser extent, again from 3 pm to 5 pm.
During these time periods, errors are more likely to occur in judgment and reaction time.
3 - 5 am
3 - 5 pm + _
Performance level

10. Human Performance
Generally, the lowest performance, alertness, and mood occur twice a day: from 3 am to 5 am, and to a lesser extent, again from 3 pm to 5 pm.
During these time periods, errors are more likely to occur in judgment and reaction time.

11. Factors affect the Circadian Rhythm
Cycles of day and night
Ambient temperature
Meal times
Napping schedule and duration
Stress and exercise
Melatonin Hormones: Natural hormones within the body, normally control wakefulness, sleepiness & circadian rhythms, under different conditions of light & activity.
It help to adjust circadian rhythms & assist in sleep management.

12. Importance of Sleep
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.
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)

13. Importance of Sleep
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.
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.
The function of sleep is to rest the mental & physical condition with gather again the energy so that they are able to make their job well. What the important is not the amount of the sleep but the quantity and the timing 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. These remedies also work for fatigue, body stress and jetlag. If they are not having enough sleep well, they can cover it by take some napping. It is another alternative to overcome fatigue which is taking a shortened period of sleeping. Not to long but as long as 5 to 10 minutes sleep are enough. Usually, people that take a nap are more active than taking a long hour sleep. Their mind especially is fresh and able to thinking well and the energy are enough for them to complete their task.
sleep debt, excessive time awake, and circadian factors (time of day) can dull good decision-making.
Flight safety depends on sharp judgment.

14. 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.
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.
In general, longer naps are more effective than short ones, but even 10 minute naps can be beneficial. It is important to note, however, that if you chose to nap longer than about 20 minutes, you will feel the effects of “sleep inertia,” a feeling of sluggishness and difficulty in waking up. Consequently, if you know you will have to perform a complex task such as flying shortly after awaking from a nap, do not nap for longer than 20 minutes.
It is better to nap when your body temperature is low, early in the morning, or in the afternoon around 1300, as this will facilitate falling asleep and the general quality of sleep.
One note of caution: A person with difficulty sleeping during their normal sleeping period should NOT nap at other times of the day, as this will perpetuate the insomnia.
Even 10 minute naps are restorative
Longer naps are better but may leave you feeling more tired (“Sleep Inertia”) for minutes after awakening
Best to nap when body temp is low (around 0300 and 1300)
Practice napping as prevention

15. JET LAG

16. 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.
Importantly, it is the timing of sleep, not necessarily the amount of sleep, that is most significant in determining whether one will be rested or fatigued.

17. Time Zone Changes During Flight
Studies have shown that complex bodily functions, such as those measurable by reaction time, performance and decision time are affected by rapid shifts through several time zones
Without proper preparation and planning, it takes one 24-hour period per one hour shift in time zone to recover
Crossing 4 time zones = 4 x 24 hours to adjust bodily cycles
A time zone is a geographical region which has the same time everywhere within it.
The world has 24 time zones, one for each hour in the day.
As the earth rotates, dawn occurs at a set hour in one time zone, then an hour later in the time zone immediately to the west and so on through the 24-hour cycle.
Thus, in the U.S., when it is 6 a.m. in the Eastern Time Zone, it is 5 a.m. in the Central Zone, 4 a.m. in the Mountain Zone, and 3 a.m. in the Pacific Zone.

18. 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”.

20. 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, and the brain may become confused and disoriented as it attempts to cope with schedules.

21. 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.

22. 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
➢ Adjust your bedtime by an hour a day a few days before your trip. This will adjust your sleep pattern to match the
sleep schedule you will keep at your destination.
➢ Reset your watch to the destination time at the beginning of your flight to help you adjust more quickly to the time
zone you will be visiting.
➢ Drink plenty of water before, during, and after your flight. The air you breathe on airplanes is extremely dry, and
some experts believe that dehydration is a predisposing cause of jet lag. Virtually everyone agrees that dehydration
can make jet lag worse.
➢ Eat lightly but strategically. What you eat can have a direct influence on your wake/sleep cycle. Remember that highprotein
meals are likely to keep you awake, while foods high in carbohydrates can promote sleep, and fatty foods
may make you feel sluggish.
➢ Relax on the first day at your destination. If you have the luxury of arriving at your destination a day or two before
you have to engage in important activities that require a lot of energy or sharp intellectual focus, give yourself a
break and let your body adjust to the time change a little more gradually.

23. FATIGUE
Fatigue is the state of feeling tired, weary, or sleepy that results from prolonged mental or physical work, extended periods of anxiety, exposure to harsh environments, or loss of sleep.
Boring or monotonous tasks may increase fatigue. As with many other physiological problems, crew members may not be aware of fatigue until they make serious errors. Sleep deprivation, disrupted diurnal cycles, or life event stress may all play a role in producing fatigue and concurrent performance decrements.
“The state of feeling tired, weary, or sleepy that results from periods of anxiety, exposure to harsh environment, or loss of sleep.”

24. Fatigue Fatigue can be defines as extreme
tiredness resulting from mental or physical
illness.
This was me writing this presentation last night !!!
CLICK
Seriously, this is bad enough safely on the ground, but while flying?!?
A decrease in skill performance related to repetitive use and duration
Also includes personal evaluation of a sense / feeling / perception of tiredness, discomfort or disorganization of muscular coordination
Aggravated by physical, physiological, and psychological states

26. 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.
INSIDIOUS in onset
Noted by aviation community for many years as having a strong impact on flight safety and efficiency
As length of fatigue increases, performance may become compromised and degraded, irritability increases, and random mistakes may occur
Lowers thresholds for other stressors
Fatigue factors are cumulative

27. Types of Fatigue There are TWO types of fatigue.
ACUTE ... short duration, recovered with good nights sleep.
CHRONIC ... occurs over a period long period of time, long recovery!
WHAT IS FATIGUE ?

28. Acute fatigue Acute single-mission skill 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
Acute single-mission skill fatigue
Results from repeating tasks during long flights or from numerous repetitive short flights
Very common
Healthy persons recover with rest / sleep
Symptoms
Tiredness
Lassitude
Loss of coordination
Inattention to details

29. Chronic fatigue Chronic fatigue
Occurs when recovery time is insufficient
Overlapping with factors of acute fatigue
Chronic skill fatigue
Occurs when recuperative time is insufficient
Overlapping with factors of acute fatigue
Can occur with any repetitive maximum effort program / job

30. 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).
The list goes on and on. So how do we address the issue? What can be done to rectify the problem? Before we can offer any solutions, we have to identify the problem. Fatigue is closely interrelated to other problems in that it can be a symptom of them, or it can be the cause. The most obvious cause of fatigue would be a lack of sleep, but other factors would include stress, anxiety and poor health. It can also be a cause of these problems. Furthermore, fatigue can be the symptom of other problems such as hypoxia and dehydration.
Disturbance of circadian rhythms
Continuous wakefulness
Cumulative sleep loss
Loss of as little as one hour sleep begins a person’s sleep debt
Eight hours of disturbed sleep can produce effect of too little sleep
Only cure for sleep debt is to sleep

31. Causes of Fatigue Long hours of working. High intensity of stress
Large temperature variations.
Noise and Vibration for long periods.
STRONG lighting.
Length of duty day
Restricted time available for sleep
Quality of sleep
Stressors such as noise, vibration, flicker, heat/cold, wearing headsets
Poor diet
Vision fatigue - loss of effective eye function from prolonged visual exertion
Dehydration
Unresolved stress

32. 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
Symptoms of fatigue include a feeling of indifference to one's performance, increased reaction time, a decreased ability to concentrate on multiple tasks, fixation, short-term memory loss, impaired judgment, impaired decision-making ability, distractibility, sloppy flying skills, reduced visual perception, loss of initiative, personality changes and depression.
Attention/Concentration difficult
Feel or appear dull and sluggish
General attempt to conserve energy
Feel or appear careless, uncoordinated, confused, or irritable
Cognitive deficits are seen before the physical effects are felt

33. Prevention of Fatigue 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
Total prevention of fatigue is impossible, but its effects can be significantly moderated. The following recommendations should be considered in any individual or crew endurance plan.
First, to ensure restful, quality sleep, the sleep environment should be cool, dark, and quiet. It is also best to avoid working or reading in bed, as this may actually contribute to problems in falling asleep. The bed should be associated only with sleeping and sexual activity. If you desire to read before going to bed, do this in a chair outside the bedroom and then go to bed.
It is also important to take actions to adjust to shift work and prevent circadian desynchronization. This can be accomplished by maintaining a consistent sleep/wake schedule even on days off. It is also important, when on the night shift, to avoid exposure to daylight from dawn to Wear sunglasses if you cannot go to sleep before the sun rises (as long as this does not pose a safety hazard), and while asleep consider wearing a sleep mask to avoid any exposure to light. Exposure to light before you go to sleep will interfere with the quality of your sleep. You may eat a light snack before going to sleep, but do not go to sleep too full or too hungry. Also avoid caffeine consumption for about 6 hours prior to going to sleep.
Maintaining good physical fitness with regular, strenuous exercise will also help resist the effects of fatigue.
The most essential action to take for treating fatigue once it’s occurred is to get plenty of natural sleep. Although alcohol is the most widely used sleep aid in the U.S., it’s use as such is not appropriate, since it is disruptive to the quality of sleep. Specifically, alcohol will put you to sleep quickly, but later in the night you will not sleep as soundly and will spend less time in REM sleep, which will cause you to feel fatigued during the waking hours.
After hours of sleep deprivation DO NOT sleep overly long during the recovery period. This could interfere with your normal sleep/wake cycle and cause sleeping problems the next night.
When trying to sleep outside your normal bedtime, prepare for sleep as you normally would have - wear the clothes to bed that you would normally wear, darken the room, and keep noise to a minimum.
If you can’t fall asleep within 30 minutes of going to bed, get up, read a boring book, like your “dash 10,” in a room other than your bedroom, preferably with soft lights, and then try again to go to bed again when you begin to feel drowsy. You may need to repeat this strategy a couples of times in a night until you are fatigued enough to fall soundly asleep.
It is also important when treating fatigue to maintain a reasonable work schedule during waking hours. It makes no sense to try to catch up on sleep and then exhaust yourself during the day. Also ensure that you eat properly to give your body the fuel it needs to recuperate.
If you find that you are having consistent sleep problems for more than two weeks, consult your flight surgeon. Also, if fatigue threatens to impair your flying, ground yourself until you are rested enough to fly again. This is certainly a more reasonable course of action than crashing an aircraft due to fatigue!