The body’s reaction to stress includes releasing chemical hormones (such as adrenaline) into the blood and increasing metabolism to provide more energy to the muscles
Examples of stressors include physical stress (noise or vibration), physiological stress (fatigue), and psychological stress (difficult work or personal situations)
Chronic stress can be defined as a level of stress that presents an intolerable burden, exceeds the ability of an individual to cope, and causes individual performance to fall sharply
Unrelenting psychological pressures, such as loneliness, financial worries, and relationship or work problems can produce a cumulative level of stress that exceeds a person’s ability to cope with the situation
When stress reaches these levels, performance falls off rapidly
Short term and is a normal occurrence in everyday living. It is the kind of tiredness people feel after a period of strenuous effort, excitement, or lack of sleep
Timing disruption — appearing to perform a task as usual, but the timing of each component is slightly off. This makes the pattern of the operation less smooth because the pilot performs each component as though it were separate, instead of part of an integrated activity
Disruption of the perceptual field — concentrating attention upon movements or objects in the center of vision and neglecting those in the periphery. This is accompanied by loss of accuracy and smoothness in control movements
The most important causes of fatigue are hypoxia, physical stress and depletion of physical energy resulting from sustained psychological stress
Extends over a long period of time and is caused by continuous high-stress levels, psychological stress or underlying disease.
An individual may experience this condition in the form of weakness, tiredness, palpitations of the heart, breathlessness, headaches, irritability, stomach and body aches problems or emotional illness
Chronic fatigue is not relieved by proper diet and adequate rest and sleep and usually requires treatment by a physician
Dehydration is the term given to a critical loss of water from the body
Causes of dehydration are hot flight decks and flight lines, wind, humidity, and diuretic drinks—coffee, tea, alcohol, and caffeinated soft drinks
Some common signs of dehydration are headache, fatigue, cramps, sleepiness, and dizziness
The first noticeable effect of dehydration is fatigue, which in turn makes top physical and mental performance difficult, if not impossible
Flying for long periods in hot summer temperatures or at high altitudes increases the susceptibility to dehydration because these conditions tend to increase the rate of water loss from the body
The body normally absorbs water at a rate of 1.2 to 1.5 quarts per hour. Individuals should drink one quart per hour for severe heat stress conditions or one pint per hour for moderate stress conditions
Even in small amounts, alcohol can impair judgment, decrease sense of responsibility, affect coordination, constrict visual field, diminish memory, reduce reasoning ability, and lower attention span
The bloodstream absorbs about 80 to 90 percent of the alcohol in a drink within 30 minutes when ingested on an empty stomach
The body requires about 3 hours to rid itself of all the alcohol contained in one mixed drink or one beer
While experiencing a hangover, a pilot is still considered under the influence of alcohol
FAR 91.17 requires that blood alcohol level be less than .04 percent and that 8 hours pass between drinking alcohol and piloting an aircraft
Even at typical general aviation altitudes, the changes in concentrations of atmospheric gases in the blood can enhance the effects of seemingly innocuous drugs that can result in impaired judgment, decision-making, and performance
Some of the most commonly used OTC drugs, antihistamines and decongestants, have the potential to cause noticeable adverse side effects, including drowsiness and cognitive deficits
Over-the-counter analgesics, such as acetylsalicylic acid (Aspirin), acetaminophen (Tylenol), and ibuprofen (Advil), have few side effects when taken in the correct dosage
Flying is almost always precluded while using prescription analgesics, since these drugs are known to cause side effects, such as mental confusion, dizziness, headaches, nausea, and vision problems
For any new medication, OTC or prescribed, you should wait at least 48 hours after the first dose before flying to determine you do not have any adverse side effects that would make it unsafe to operate an aircraft
Caused by the brain receiving conflicting messages about the state of the body
Symptoms of motion sickness include general discomfort, nausea, dizziness, paleness, sweating, and vomiting
If symptoms of motion sickness are experienced, opening fresh air vents, focusing on objects outside the airplane, and avoiding unnecessary head movements may help alleviate some of the discomfort
Lungs can’t transfer oxygen to blood, brain doesn’t receive enough oxygen
Dry ice sublimates into large quantities of CO2 gas, which can rapidly displace oxygen-containing air and potentially cause hypoxia via carbon dioxide intoxication
Causes can include shock, the heart failing to pump blood effectively, a constricted artery, excessive gravity acceleration (Gs), and cold temperatures
Reduction in mental function while flying which can result in life-threatening errors
Headache, drowsiness, dizziness, lightheadedness, impaired judgment, decreased reaction time, euphoria, visual impairment, cyanosis and numbness in finger and toes
Colorless and odorless gas produced by all internal combustion engines
By attaching itself to the hemoglobin in the blood about 200 times more easily than oxygen, CO prevents the hemoglobin from carrying oxygen to the cells, resulting in hypemic hypoxia
Aircraft heater vents and defrost vents may provide CO a passageway into the cabin, particularly if the engine exhaust system has a leak or is damaged
Effects can include headache, blurred vision, dizziness, drowsiness, and/or loss of muscle power
Immediate corrective action should be taken including turning off the heater, opening fresh air vents and windows, and using supplemental oxygen, if available
Responsible for color vision, well suited to detecting fine detail and color in high light levels
Fovea - the center of the visual field at the back of the retina where almost all the light sensing cells are cones and detail, color sensitivity, resolution are highest
To see an object clearly at night, the pilot must expose the rods to the image, this can be done by looking 5° to 10° off center of the object to be seen
Altitude-Induced Decompression Sickness (DCS) describes a condition characterized by a variety of symptoms resulting from exposure to low barometric pressures that cause inert gases (mainly nitrogen), normally dissolved in body fluids and tissues, to come out of physical solution and form bubbles
If the nitrogen is forced to leave the solution too rapidly, bubbles form in different areas of the body causing a variety of signs and symptoms
A pilot or passenger who intends to fly after scuba diving should allow the body sufficient time to rid itself of excess nitrogen absorbed during diving
