Private Pilot | Lesson 12 - Aeromedical Factors and Aeronautical Decision Making

TABLE OF CONTENTS:
12.1 SPATIAL DISORIENTATION
12.2 CARBON MONOXIDE
12.3 VISION
12.4 HYPOXIA
12.5 HYPERVENTILATION
12.6 AERONAUTICAL DECISION MAKING (ADM)

12.1 Spatial Disorientation

Spatial disorientation is the sensation of disorientation resulting in your body not knowing whether you are going up or down. It is a state of temporary confusion resulting from conflicting and misleading information being sent to the brain by various sensory organs - usually your eyes, your inner ear and the nerves in your skin and muscles.

If you lose outside visual references and become disoriented, this is spatial disorientation. This occurs when you rely on the sensations of muscles and inner ear to tell you what the airplane's attitude is. This might occur during a night flight, while practicing aircraft maneuvers, or when flying through clouds.

You must learn to rely on the airplane instruments, and ignore the sensations of your body when you are disoriented. Trust your instruments.

12.2 Carbon Monoxide

Carbon Monoxide is a clear and odorless gas that is given off by all gas burning engines. It is usually carried away from the aircraft through the engine exhaust. But, a cracked exhaust or other defect in the aircraft could allow carbon monoxide to leak into the aircraft cabin.

Carbon Blurred (hazy) thinking, uneasiness, dizziness, and tightness across the forehead are early symptoms of carbon monoxide poisoning. They are followed by a headache and, with large accumulations of carbon monoxide, a loss of muscle power.

Increases in altitude increase susceptibility to carbon monoxide poisoning because of decreased oxygen availability.

12.3 Vision

The best method of visually scanning for traffic is to essentially, look carefully at small sections of the sky, one at a time. Or, as the FAA recommends, bring small portions of the sky into the central field of vision slowly in succession.

Haze can create the illusion of traffic or terrain being farther away than they actually are. Stay extra vigilant in your traffic scan when flying in haze.

When you do spot another aircraft, any aircraft that appears to have no relative motion with respect to your aircraft and stays essentially in the same place should be considered on a collision course. If it increases in size, you should take immediate evasive action.

In daylight, the most effective way to scan for other aircraft is to use a series of short, regularly-spaced eye movements that bring successive areas of the sky into your central visual field. Each movement should not exceed 10°, and each area should be observed for at least one second to enable detection.

Or, in other words, look only at small sections of the airspace around you for short periods of time, then move to the next small section of airspace - don't try to look "everywhere, all at once." Only a very small center area of the eye has the ability to send clear, sharply focused messages to the brain.

Night flying also requires special care. Pilots should adapt their eyes for night flying by avoiding bright white lights for at least 30 minutes prior to the flight.

And, due to the eye's physiology, off-center eyesight is better than direct at night. Because of this, pilots should scan slowly at night, and look at the side of the object to permit off-center viewing.

At night, because of the way our eyes are made up, scanning must use the off-center portions of the eyes, the off-center portions are most effective at seeing objects at night. So, peripheral vision should be used, scanning small sectors and using off-center viewing.

Basically, at night, you shouldn't try to look directly at a lit object but instead, look slightly to one side of it.

12.4 Hypoxia

Flying at very high altitude may result in hypoxia. Hypoxia is an oxygen deficiency in the body that may cause lack of clear thinking, fatigue, euphoria, and, shortly thereafter, unconsciousness.

12.5 Hyperventilation

Hyperventilation occurs when rapid or extra breathing while on oxygen results in large quantities of air breathed in and out of the lungs. Hyperventilation can also occur if one becomes excited or stressed by tension, or fear, or anxiety. This results in an excessive amount of carbon dioxide expelled out of the lungs and too much oxygen retained.

Hyperventilation can cause dizziness, hot and cold sensations, and nausea.

Overcome hyperventilation symptoms by slowing your breathing rate - try breathing into a bag, or talking aloud.

12.6 Aeronautical Decision Making (ADM)

Aeronautical decision-making (ADM) is decision-making in a unique environment—aviation. It is a systematic approach to the mental process used by pilots to consistently determine the best course of action in response to a given set of circumstances. It is what a pilot intends to do based on the latest information he or she has. For over 25 years, the importance of good pilot judgment, or aeronautical decision-making (ADM), has been recognized as critical to the safe operation of aircraft, as well as accident avoidance.

Pilots of all capabilities can exhibit dangerous tendencies or behavioral problems at some point. For example, scud running, continuing a visual flight into instrument conditions, and neglecting checklists are three examples of common dangerous tendencies that must be recognized and corrected by an individual pilot.

• In scud running, a pilot pushes his/her capabilities to dangerous limits in an attempt to maintain visual contact with the ground while flying lower and lower to avoid clouds and low ceilings.
• Continuing a visual flight into instrument conditions can lead to spatial disorientation in a non-instrument rated pilot or aircraft, and potential loss of aircraft control or collision with the ground or other obstacles.
• Neglect of checklists is simply a pilot's reliance on memory for repetitive tasks, usually resulting in missed preparation actions.

ADM addresses five hazardous attitudes that contribute to poor pilot judgment.

1. Antiauthority - Don't tell me!
2. Impulsivity - Do something quickly!
3. Invulnerability - It won't happen to me.
4. Macho - I can do it.
5. Resignation - What's the use?

Hazardous attitudes contribute to poor pilot judgment but can be effectively counteracted by redirecting the hazardous attitude so that correct action can be taken. Recognition of hazardous thoughts is the first step toward neutralizing them.

After recognizing a thought as hazardous, the pilot should label it as hazardous, then state the corresponding antidote. Antidotes should be memorized.

1. Antiauthority - Don't tell me! » "Follow the rules. They are usually right."
2. Impulsivity - Do something quickly! » "Not so fast. Think first."
3. Invulnerability - It won't happen to me » "It could happen to me."
4. Macho - I can do it » "Taking chances is foolish."
5. Resignation - What's the use? » "I'm not helpless. I can make a difference."

Additionally, you, as the pilot, are responsible for determining whether or not you are fit to fly for a particular flight. One of the best ways to single pilots can mitigate risk is to use a personal checklist to determine physical and mental readiness for ?ying.

Human error is one of the leading common factors that affects most preventable aircraft accidents. Use of good ADM increases the probability of a safe ?ight, and decreases the probability of human error.

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