Aeromedical Factors (GA)

Question 1

What is the

I’M SAFE Checklist?

Answer 1

Illness

Medication

Stress

Alcohol

Fatigue

Eat

Question 2

What are some examples in the

I’M SAFE Checklist?

Answer 2

Illness - Do I have any symptoms?

Medication - Have I been taking prescription or over-the-counter drugs?

Stress - Am I under psychological pressure from the job? Worried about financial matters, health problem, or family discord?

Alcohol - Have I been drinking within 8 hours? Within 24 hours?

Fatigue - Am I tired and not adequately rested?

Eat - Am I adequately nourished?

Question 3

What are the three types of

Medical Certificates?

Answer 3

3RD CLASS (private or recreational) - 60 months or 24 months if over 40

2ND CLASS (commercial pilots, copilot) - 12 months

1ST CLASS (Airline Transport Pilot, captain) - 6 months

* Valid periods under which class you’re operating. Bill has a 1st class medical but is working under 3rd class so his first class is valid for 60 months.

Question 4

What is

Hypoxia?

Answer 4

Hypoxia means “reduced oxygen” or “not enough oxygen.”

A lack of oxygen in the body for any reason.

Question 5

What are the

Four Types of Hypoxia?

Answer 5

Hypoxic Hypoxia

Hypemic Hypoxia

Histotoxic Hypoxia

Stagnant Hypoxia

Question 6

What is

Hypoxic Hypoxia?

Answer 6

Lack of air pressure to push oxygen molecules through lungs. Lack of oxygen in the blood stream.

Question 7

What is

Hypemic Hypoxia?

Answer 7

Blood is unable to carry sufficient oxygen to cells.

Caused by genetic disorders or external factors (Anemic, smoking, inhaling fumes, giving blood).

Question 8

What is

Histotoxic Hypoxia?

Answer 8

The inability of cells to use oxygen.

Caused by drugs and alcohol such as narcotics and poisons.

Drinking 1 oz. of alcohol can equate to about 2,000 ft of physiological altitude (altitude your body thinks it’s at).

Question 9

What is

Stagnant Hypoxia?

Answer 9

Poor circulation of blood or pooling.

Caused by G-forces, lack of blood circulation, shock, and even sitting positions.

Question 10

What are the

Symptoms of Hypoxia?

Answer 10

Cyanosis (blue fingernails and lips)

Headache

Decreased reaction time

Impaired judgment

Euphoria

Visual Impairment

Drowsiness

Lightheaded or dizzy sensation

Tingling in fingers and toes

Numbness

Since symptoms are broad in range and different for everyone, the FAA recommends altitude chamber experience.

Question 11

What are the

Treatments for Hypoxia?

Answer 11

Treatment of hypoxia includes flying at lower altitudes and/or using supplemental oxygen in non-pressurized aircraft.

Question 12

What are the

FAR Part 91.211 Oxygen Use Requirements

for Non-pressurized Aircraft?

Answer 12

>12500-14000- Minimum flight crew must have oxygen if at those levels for more than 30 minutes.

14000-14999- Minimum flight crew at those levels.

>15000- Everyone one board must have access to supplemental oxygen.

Question 13

What are the

FAR Part 91.211 Oxygen Use Requirements

for Pressurized Aircraft?

Answer 13

FL250- 10 minute supply for everyone, for emergency descent.

FL350- Quick donning. Don’t have to put it on unless only 1 pilot is flying.

FL410- Both pilots must wear a mask.

Question 14

What is

Hyperventilation?

Answer 14

Hyperventilation is the excessive rate and depth of respiration leading to abnormal loss of carbon dioxide from the blood.

Question 15

What are the

Common Symptoms of Hyperventilation?

Answer 15

Visual impairment

Unconsciousness

Lightheaded or dizzy sensation

Tingling sensations

Hot and cold sensations

Muscle spasms

Question 16

What are the

Treatment Options for Hyperventilation?

Answer 16

The treatment for hyperventilation involves restoring the proper carbon dioxide level in the body.

Breathing normally is both the best prevention and the best cure for hyperventilation.

In addition to slowing the breathing rate, breathing into a paper bag or talking aloud helps to overcome hyperventilation.

Recovery is usually rapid once the breathing rate is returned to normal.

Question 17

Middle Ear and Sinus Problems

Answer 17

Occurs normally during climbs and descents (especially when sick or having sinus issues).

Blockage in the inner ear causes pressure change during flight and causes air in the nasal cavity to push against the inner ear, causing severe pain.

Treatment could include leveling off and trying the Valsalva technique or even climbing back up in altitude to alleviate the excess outside pressure when Valsalvaing.

Question 18

Motion Sickness/ Spacial Disorientation

Answer 18

Three senses:

• Somatosensory/Kinesthetic (seat of pants flying)
• Visual system
• Vestibular system (inner ear)

When these three systems have conflicting information your body can become disoriented.

A pilot can reduce susceptibility to disorienting illusions through training and awareness, and learning to rely totally on flight instruments.

Question 19

Vestibular Illusions

Answer 19

The Leans - abrupt recovery or rapid bank correction interpreted as roll and prompts you to re-enter bank.

Coriolis Illusion - during a constant rate turn you turn your head quickly giving an overwhelming sense of tilt, rotation or turn (most dangerous).

Graveyard Spiral - loss of altitude in a prolonged constant-rate turn. Interpreted as wings level descent.

Somatogravic Illusion - rapid acceleration that produces the illusion of nose-high altitude and prompts you to enter a dive.

Inversion Illusion - an abrupt change from climb to level creates a tumbling back illusion.

Elevator Illusion - an abrupt upward vertical acceleration, as can occur in an updraft, can stimulate the otolith organs to create the illusion of being in a climb.

Question 20

Visual Illusions

Answer 20

False Horizons - A sloping cloud formation, an obscured horizon, an aurora borealis, a dark scene spread with ground lights and stars, and certain geometric patterns of ground lights can provide inaccurate visual information, or false horizon, for aligning the aircraft correctly with the actual horizon. The disoriented pilot may place the aircraft in a dangerous attitude.

Autokinesis - In the dark, a stationary light will appear to move about when stared at for many seconds. The disoriented pilot could lose control of the aircraft in attempting to align it with the false movements of this light.

Question 21

Optical Illusions

Answer 21

Runway Width illusion - A narrower-than-usual runway can create an illusion the aircraft is at a higher altitude than it actually is, especially when runway length-to-width relationships are comparable. The pilot who does not recognize this illusion will fly a lower approach, with the risk of striking objects along the approach path or landing short. A wider-than-usual runway can have the opposite effect, with the risk of the pilot leveling out the aircraft high and landing hard, or overshooting the runway.

Runway and Terrain Slopes Illusion - An upsloping runway, upsloping terrain, or both, can create an illusion that the aircraft is at a higher altitude than it actually is. The pilot who does not recognize this illusion will fly a lower approach. Downsloping runways and downsloping approach terrain can have the opposite effect.

Featureless Terrain Illusion - An absence of surrounding ground features, as in an overwater approach, over darkened areas, or terrain made featureless by snow, can create an illusion the aircraft is at a higher altitude than it actually is. This illusion, sometimes referred to as the “black hole approach,” causes pilots to fly a lower approach than is desired.

Water Refraction - Rain on the windscreen can create an illusion of being at a higher altitude due to the horizon appearing lower than it is. This can result in the pilot flying a lower approach.

Haze - Atmospheric haze can create an illusion of being at a greater distance and height from the runway. As a result, the pilot will have a tendency to be low on the approach. Conversely, extremely clear air (clear bright conditions of a high altitude airport) can give the pilot the illusion of being closer than he or she actually is, resulting in a high approach, which may result in an overshoot or go around. The diffusion of light due to water particles on the windshield can adversely affect depth perception. The lights and terrain features normally used to gauge height during landing become less effective for the pilot.

Fog - Flying into fog can create an illusion of pitching up. Pilots who do not recognize this illusion will often steepen the approach quite abruptly.

Ground Lighting Illusions - Lights along a straight path, such as a road or lights on moving trains, can be mistaken for runway and approach lights. Bright runway and approach lighting systems, especially where few lights illuminate the surrounding terrain, may create the illusion of less distance to the runway. The pilot who does not recognize this illusion will often fly a higher approach.

Question 22

Carbon Monoxide Poisoning

Answer 22

Excess of CO2.

CO2 sticks to hemoglobin more than it should (200x more than O molecules).

Nausea, headache, dizziness, weakness, etc.

Open vents/ windows (non-pressurized aircraft), oxygen mask on, descend ASAP.

Question 23

Stress

Answer 23

Stress is the body’s response to physical and psychological demands placed upon it.

Stress falls into two broad categories, acute (short term) and chronic (long term).

Acute stress involves an immediate threat that is perceived as danger. This is the type of stress that triggers a “fight or flight” response in an individual, whether the threat is real or imagined.

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.

Question 24

Fatigue

Answer 24

Fatigue is frequently associated with pilot error. Some of the effects of fatigue include degradation of attention and concentration, impaired coordination, and decreased ability to communicate. These factors seriously influence the ability to make effective decisions. Physical fatigue results from sleep loss, exercise, or physical work. Factors such as stress and prolonged performance of cognitive work result in mental fatigue.

Acute fatigue is 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. Rest after exertion and 8 hours of sound sleep ordinarily cures this condition.

Chronic fatigue, extending over a long period of time, usually has psychological roots, although an underlying disease is sometimes responsible. Continuous high-stress levels produce chronic fatigue. Chronic fatigue is not relieved by proper diet and adequate rest and sleep, and usually requires treatment by a physician.

If suffering from acute fatigue, stay on the ground. If fatigue occurs in the flight deck, no amount of training or experience can overcome the detrimental effects. Getting adequate rest is the only way to prevent fatigue from occurring. Avoid flying without a full night’s rest, after working excessive hours, or after an especially exhausting or stressful day. Pilots who suspect they are suffering from chronic fatigue should consult a physician.

Question 25

Dehydration

Answer 25

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.

To help prevent dehydration, drink two to four quarts of water every 24 hours. Since each person is physiologically different, this is only a guide. Most people are aware of the eight-glasses-a-day guide: If each glass of water is eight ounces, this equates to 64 ounces, which is two quarts. If this fluid is not replaced, fatigue progresses to dizziness, weakness, nausea, tingling of hands and feet, abdominal cramps, and extreme thirst.

The key for pilots is to be continually aware of their condition. Most people become thirsty with a 1.5 quart deficit, or a loss of 2 percent of total body weight. This level of dehydration triggers the “thirst mechanism.” The problem is that the thirst mechanism arrives too late and is turned off too easily. A small amount of fluid in the mouth will turn this mechanism off and the replacement of needed body fluid is delayed.

Other steps to prevent dehydration include:

• Carrying a container in order to measure daily water intake.
• Staying ahead—not relying on the thirst sensation as an alarm. If plain water is offensive, add some sport drink flavoring to make it more acceptable.
• Limiting daily intake of caffeine and alcohol (both are diuretics and stimulate increased production of urine).

Question 26

Heatstroke

Answer 26

Heatstroke is a condition caused by any inability of the body to control its temperature. Onset of this condition may be recognized by the symptoms of dehydration, but also has been known to be recognized only by complete collapse.

To prevent these symptoms, it is recommended that an ample supply of water be carried and used at frequent intervals on any long flight, whether thirsty or not. The body normally absorbs water at the 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. If the aircraft has a canopy or roof window, wearing light-colored, porous clothing and a hat will help provide protection from the sun. Keeping the flight deck well ventilated aids in dissipating excess heat.

Question 27

Scuba Diving

Answer 27

Wait 24 hours* after scuba diving before getting in an airplane.

Nitrogen out of bloodstream (bubbles) = painful or could cause heart attack or embolism and death. (Going from low pressure to high pressure is fine. I can fly then dive, but not dive then fly.)

Decompression (lower levels) = 24 hours

Compression = 12 hours (but 24 safer)

Question 28

Vision in Flight

Answer 28

The eye functions much like a camera. Its structure includes an aperture, a lens, a mechanism for focusing, and a surface for registering images. Light enters through the cornea at the front of the eyeball, travels through the lens, and falls on the retina. The retina contains light-sensitive cells that convert light energy into electrical impulses that travel through nerves to the brain. The brain interprets the electrical signals to form images. There are two kinds of light-sensitive cells in the eyes: rods and cones.

The cones are responsible for all color vision, from appreciating a glorious sunset to discerning the subtle shades in a fine painting. Cones are present throughout the retina, but are concentrated toward the center of the field of vision at the back of the retina. There is a small pit called the fovea where almost all the light sensing cells are cones. This is the area where most “looking” occurs (the center of the visual field where detail, color sensitivity, and resolution are highest).

While the cones and their associated nerves are well suited to detecting fine detail and color in high light levels, the rods are better able to detect movement and provide vision in dim light. The rods are unable to discern color but are very sensitive at low light levels. The trouble with rods is that a large amount of light overwhelms them, and they take a long time to “reset” and adapt to the dark again. There are so many cones in the fovea that the very center of the visual field hardly has virtually no rods at all. So in low light, the middle of the visual field is not very sensitive, but farther from the fovea, the rods are more numerous and provide the major portion of night vision.

The area where the optic nerve enters the eyeball has no rods or cones, leaving a blind spot in the field of vision. Normally, each eye compensates for the other’s blind spot.

Question 29

Empty Field Myopia

Answer 29

When there are very few references to go off of.

Causes you to focus on things closer than you think (dirty windshield, dash, etc.)