Aeromedical Factors

Objective:

Describe how to obtain a medical certificate with and without a medical deficiency. Identify all the categories of aeromedical factors as relating to flight and decision-making. Describe how each factor can affect pilot performance. Set the stage for a creation of personal minimums relating to medical factors.

Attention:

Story of “John the instructor”—post cold illness, Emergency Descent

Motivation:

How would your medical condition affect your flying and decision making?
Why is it important to learn aeromedical factors?
What does having a medical certificate really mean?

Overview:

Breathing, balance, middle-ear/sinus, visual/illusions, stress, fatigue, diet, scuba, medical certificate, I’M SAFE checklist.


Log Ground Training:

  • 61.105(b)(12) Aeronautical decision making and judgment;

Aeromedical Factors and Night

Development:

How to obtain a Medical Certificate

  • Get a physical from an Aviation Medical Examiner who deems you medically fit to fly at the time, according to FAR Part 67 Medical Standards
    • He/she issues you a medical certificate after their evaluation
    • If there is a deficiency but you are capable of performing airman duties without endangering public safety, work with your AME to apply for a Statement of Demonstrated Ability (SODA) i.e.
      • Loss of appendage
      • Vision deficiency
      • Etc.
    • Student pilots need a third class medical, which includes privileges for student, recreation, and private pilots
    • Refer also to the FAA’s Frequently Asked Questions about Aviation Medicals

Physiological Considerations

  • Hypoxia—reduced oxygen, or not enough oxygen
    • Hypoxic: insufficient oxygen available to the body—blocked airway, drowning, altitude, low barometric pressure
    • Stagnant: “not flowing”—too many G’s, shock, too cold
    • Hypemic: blood is unable to transport enough Oxygen to the cells, “not enough blood”—loss of blood, anemia, after donating blood
    • Histoxic: inability of cells to effectively use oxygen. “poisoned cells”—alcohol, drugs, poisons, etc.
    • Symptoms of Hypoxia
      • Blue fingernails and lips: Cyanosis
      • Headache
      • Decreased reaction time
      • Impaired judgment
      • Euphoria
      • Visual impairment
      • Drowsiness
      • Lightheaded or dizzy sensation
      • Tingling in fingers and toes
      • Numbness
  • Hyperventilation—excessive respiration leading to abnormal loss of carbon dioxide from blood
    • Symptoms of Hyperventilation
      • Visual impairment
      • Unconsciousness
      • Lightheaded or dizzy sensation
      • Tingling sensations
      • Hot and cold sensations
      • Muscle spasms
  • Middle ear and sinus problems (PHAK 16-4)
    • Attention: Scuba diving experiment
    • The effect of nitrogen excesses during scuba dives and how this affects pilots and passengers during flight.
    • Altitude-induced Decompression Sickness (DCS)
    • Climbs/Descents, air pockets compress/expand, painful
      • Eustachian (you-stay-she-un) Tube—ear to throat
  • Spatial disorientation and illusions
    • Attention: close your eyes and balance on an uneven stool.
    • Vestibular Illusions PHAK 16-6
      • The leans—bank too slow, fluid in ear canal doesn’t move
      • Corolis Illusion—when turning long enough, fluid slows to be moving at the same speed
      • Graveyard spiral—Coriolis illusion tricks pilot to return to bank, compensates for loss of altitude by pulling up and tightens descending spiral
      • Somatogravic illusion—rapid acceleration feels like nose up
      • Inversion illusion—change from climb to straight-and-level feels like tumbling backward
      • Elevator illusion—abrupt upward (or downward) movement feels like a climb
      • Postural Considerations—seat of pants flying
      • Demonstrations on Spatial Disorientation
        • Climbing while accelerating
        • Climbing while turning
        • Diving while turning
        • Tilting to right or left
        • Reversal of Motion
        • Diving or Rolling beyond the vertical plane
      • Coping with Spatial Disorientation
        • Stay aware
        • Preflight weather briefing
        • Flying conditions like over water, in clouds, reduced visibility
        • Do not continue in adverse weather conditions
        • Use outside visual references, fixed points on Earth’s surface
        • Avoid sudden head movement, particularly during takeoffs, turns, and approaches to landing
        • Physiologically prepared
        • Flight instrument proficient
  • Vision
  • Vision is the most important sense for safe flight
    • Attention: balance on one foot (control). Make a paper telescope, close one eye, look through the telescope with the other eye, balance on one foot.
  • Visual Illusions
    • Empty-Field Myopia: “looking without seeing” when there seems nothing specific to focus on (in clouds or haze).
    • False horizon
    • Autokinesis: happens when you stare at a single point of light against a dark background for more than a few seconds, and it appears to move on its own.
    • Night landing: featureless terrain, dark runway environment, wide runways, mistaken approach lights, etc.
    • False Horizon: when the natural horizon is obscured or not readily apparent.
      • Runway width illusion
      • Runway and terrain slopes illusion
      • Featureless Terrain Illusion
      • Water Refraction—rain on windscreen
      • Haze
      • Fog
    • Ground lighting illusions
      • Reduce by:
        • Anticipate possibilities
        • Frequently reference altimeter, especially approaches
        • Aerial visual inspection before landing
        • Use VASI or PAPI
        • Utilize visual decent point
        • Recognize chances of accidents or emergencies, and distractions
        • Maintain optimum proficiency in landing procedures
  • Motion sickness
  • Carbon monoxide poisoning
  • Fatigue and Stress
  • Dehydration
  • Alcohol and Drugs
    • Consider the effects of alcohol and drugs, and their relationship to flight safety. PHAK 16-13
      • Seriously affects motor skills, reaction time, mental ability, etc.
  • See table in PHAK 16-15

I’M SAFE checklist:

  • Illness
  • Medication
  • Stress
  • Alcohol/attitude
  • Fatigue
  • Emotional/eating

Creating personal minimums: decide now not to fly if you are ever sick, whenever you are upset, etc.

Conclusion and Evaluation:

Medical condition affects your flying and decision making significantly. It is important to learn aeromedical factors to decide not to fly before a critical situation is encountered, and to recognize symptoms of oncoming situations. All your medical certificate means is that you appeared capable physically at the time of the examination; personal minimums should be created to determine before every flight if a pilot is ready for all the possible stresses of flying.