A valid medical certificate is required to exercise pilot privileges and is obtained through an exam with an Aviation Medical Examiner. There are three classes of medical certificates - third, second, and first class - with increasing standards and privileges. Physiological and psychological factors like hypoxia, hyperventilation, spatial disorientation, fatigue, and stress can affect pilot performance. Vision plays a key role in flight but can be impacted by illusions like autokinesis and false horizons in certain conditions.

1. Aeromedical Factors Groups B/D: First Year

2. Essential Questions What is a medical certificate and what ranks are there? What different types of physiological factors can affect pilots during flight? In what ways can your vision trick you during flight?

3. Obtaining a Medical Certificate Valid medical certificate required to exercise privileges of airman certificates (exception of glider and free balloon pilots) Acquisition of medical requires exam by AME (aviation medical examiner)

4. Obtaining a Medical Certificate Third class Required for private or recreational 3 years for under 40 years old, 2 years otherwise Second class Required for commercial 1 year First class Required for ATP 6 months

5. Obtaining a Medical Certificate Higher the class, more rigorous the standards Higher class medicals have met requirements for lower classes First class lasts for 2 (or 3) years for private/recreational, same applies for second class 14 CFR part 67 14 CFR part 61

6. Physiological Factors Affecting Pilot Performance Hypoxia Hyperventilation Middle Ear/Sinus Problems Spatial Disorientation Illusions Posture Motion Sickness CO Poisoning Stress Fatigue Dehydration/Heatstroke Alcohol Drugs

7. Hypoxia Means “reduced oxygen” or “not enough oxygen” Most concern is with getting enough oxygen to brain Reduction in mental function while flying can result in life-threatening errors Hypoxia can be caused by insufficient supply of oxygen, inadequate transportation of oxygen, or inability of the body tissues to use oxygen

8. Symptoms of Hypoxia Cyanosis (blue fingernails/lips) Headache Decreased reaction time Impaired judgment Euphoria Visual impairment Drowsiness Lightheaded or dizzy sensation Tingling in fingers and toes Numbness

9. Time of useful consciousness describes maximum time the pilot has to make rational, life-saving decisions and carry them out at a given altitude without supplemental oxygen

10. Hyperventilation Excessive rate and depth of respiration leading to abnormal loss of carbon dioxide from the blood Disturbing symptoms can alarm the uninformed pilot Can lead to unconsciousness due to respiratory system’s overriding mechanism to regain control of breathing Breathing more rapidly than normal in a stressful situation can lead to hyperventilation

11. Symptoms of Hyperventilation Visual impairment Unconsciousness Lightheaded or dizzy sensation Tingling sensations Hot and cold sensations Muscle spasms Breathe normally or into a bag to recover from hyperventilation. Talking aloud also helps.

12. Middle Ear and Sinus Problems Air inside body cavities expands due to difference in air pressure at higher altitudes Middle ear is a small cavity located in the bone of the skull Air can get trapped inside middle ear and cause a uncomfortable difference in pressure internally and externally Greater external pressure, eardrum will bulge inward; greater internal pressure, eardrum will bulge outward

14. Middle Ear and Sinus Problems This is why you don’t go flying when you’re sick!!! Swelling can cause closing of Eustachian tube and pressure difference cannot be relieved Can be damaging to eardrums Air pressure in sinuses also equalizes with pressure in flight deck that connect sinuses to nasal passages Respiratory infection, allergies, colds, etc. can lead to slow equalization and cause discomfort

15. Spatial Disorientation Lack of orientation with regard to position, attitude, or movement of airplane in space Three body systems working together to decide orientation in space: 1. vestibular system: organs in inner ear that sense position by balance 2. somatosensory system: nerves in skin, muscles, and joints which, along with hearing, sense position based on gravity, feeling, sound 3. visual system: eyes sense position based on what is seen Flying can sometimes cause systems to supply conflicting information to the brain, leading to disorientation

16. Carbon Monoxide (CO) Poisoning CO is a colorless, odorless gas produced by all internal combustion engines CO prevents hemoglobin from carrying oxygen to cells, resulting in hypoxia Body requires up to 48 hours to dispose of CO If CO poisoning is severe enough, it can lead to death

17. Carbon Monoxide (CO) Poisoning Effects: Headache Blurred vision Dizziness Drowsiness Loss of muscle power

18. Stress Body’s response to physical and psychological demands placed upon it Stressor is an element that causes stress Physical stress (noise or vibration) Physiological stress (fatigue) Psychological stress (difficult work or personal situations) Acute stress Immediate threat that is perceived as danger “Fight or Flight” Can lead to chronic stress Chronic stress Level of stress that presents an intolerable burden, exceeds the ability of an individual to cope, and causes individual performance to fall sharply

19. Fatigue FREQUENTLY ASSOCIATED WITH PILOT ERROR Acute Short term Normal occurrence in everyday living Chronic Long term Usually has psychological roots Best way to prevent is to get adequate rest

21. Vision in Flight Of all senses, vision is most important for flight Structure of eye includes an aperture, lens, mechanism for focusing, and surface for registering images Rods and cones are light-sensitive cells that convert light energy into electrical signals that are sent to the brain Cones Responsible for all color vision Concentrated toward center of field of vision Rods Responsible for detecting movement and provide vision in dim light No rods or cones in area where optic nerve enters eyeball leaves blind spot in field of vision

22. Find Your Blind Spot

23. Autokinesis Caused by staring at a single point of light against dark background for more than a few seconds Light appears to move on its own after a few moments Focus eyes on objects at varying distances to prevent illusion and avoid fixating on one target

24. False Horizon Natural horizon is obscured or not readily apparent Can be generated by confusing bright stars and city lights Can also occur while flying toward shore of ocean or large lake

25. Night Illusions Pilots are more likely to fly a lower-than-normal approach Lights should always be as dim as possible during landing so as to have correct depth perception Visual obscurities can cause night illusions Rain Haze