1. AEROMEDICAL FACTORS
CW2 Brandt 1

2. AGENDA FATIGUE SELF-IMPOSED STRESSES HYPOXIA SPATIAL DISORIENTATION
MIDDLE EAR DISCOMFORT 2

3. REFERENCES FM 1-301 AR 40-8 The American Heritage® Dictionary
Phil’s Study Guide 3

4. FATIGUE
Definition
Physical or mental weariness resulting from exertion. Desire or need for rest.
Physiology. The decreased capacity or complete inability of an organism, an organ, or a part to function normally because of excessive stimulation or prolonged exertion. 4

5. ACUTE FATIGUE Associated with long work days Characteristics
Inattention/Distractibility
Errors in timing
Need for greater stimuli
Neglect of secondary tasks
Loss of accuracy and control
Unawareness of error accumulation
Overcome by adequate rest or sleep 5

6. CHRONIC FATIGUE Results from successive periods of acute fatigue
Characteristics
Insomnia Irritability
Depression Poor judgement
Weight loss Loss of appetite
Slowed reaction time
Several sleep periods & reduced work schedule can help eliminate 6

7. REDUCTION OF FATIGUE Physical fitness Limit self-imposed stress
Good living conditions, food, rest
Limit work periods
Deal effectively with stress and acute fatigue
Take regular leave
Practice crew endurance
Ergonomics 7

8. SELF-IMPOSED STRESSES
Drugs
Exhaustion
Alcohol
Tobacco
Hypoglycemia/Nutrition 8

9. HYPOXIA
Results from having an insufficient amount of oxygen in the body, or the inability of the body to utilize the oxygen.
Normally associated with high altitude, but many other factors interfere with the blood ability to carry oxygen. 9

10. TYPES OF HYPOXIA
HYPOXIC
HYPEMIC
STAGNENT
HISTOTOXIC 10

11. HYPOXIC HYPOXIA Insufficient oxygen, reduced PO2
Occurs at higher altitudes 11

12. HYPEMIC HYPOXIA Reduction of oxygen carrying capacity of the blood
Anemia, Blood Loss, and the presence of Carbon Monoxide (CO) 12

13. STAGNANT HYPOXIA Inadequate circulation of the blood
Heart Failure, Venous Pooling (High G’s) 13

14. HISTOTOXIC HYPOXIA
Body tissue poisoned, can not absorb oxygen from the blood
Alcohol, narcotics, and certain poisons 14

15. STAGES OF HYPOXIA
INDIFFERENT
COMPENSATORY
DISTURBANCE
CRITICAL 15

16. INDIFFERENT STAGE O2 Saturation 98%-90% Altitude 0-10 Thousand feet
Symptoms
Decrease In Night Vision 16

17. COMPENSATORY STAGE O2 Saturation 90%-80% Altitude 10-15 Thousand feet
Symptoms
Drowsiness
Poor Judgement
Impaired Coordination
Impaired Efficiency
Increased pulse and respiration to compensate 17

18. DISTURBANCE STAGE O2 Saturation 80%-70% Altitude 15-20 Thousand feet
Symptoms
Flight Control Vision
Handwriting/Speech Memory
Coordination Judgement
Decreased Sensation to Pain
Physiological responses can no longer compensate for oxygen deficiency 18

19. CRITICAL STAGE O2 Saturation 70%-60% Altitude 20-25 Thousand feet
Symptoms
Circulatory Failure
CNS Failure/Convulsions
Convulsions
DEATH
Within 3-5 minutes, judgement and coordination deteriorates 19

20. PREVENTION LIMIT TIME AT ALTITUDE (AR 95-1) 10-12 Thousand Ft 1 Hour
12-14 Thousand Ft 30 Min
>14 Thousand Ft Sup. Oxygen 20

21. SPATIAL DISORIENTATION
Defined as- an individuals inaccurate perception of actual position, attitude, and motion relative to the center of the earth.
Pilots rely on false information their senses provide
Contributes to more accidents than any other physiological problem in flight. 21

22. COMMON TERMS ORIENTATION or EQUILIBRIUM SENSORY ILLUSION VERTIGO
PILOT’S VERTIGO 22

23. EQUILIBRIUM MAINTENANCE
VISUAL SYSTEM
Most Important/Reliable
Use Visual Sensory Input to avoid disorientation 23

24. EQUILIBRIUM MAINTENANCE
VESTIBULAR SYSTEM
Otolith Organs
Semicicular Canals 24

25. EQUILIBRIUM MAINTENANCE
PROPRIOCEPTIVE SYSTEM
reacts to pressure on the joints, muscles, and skin
“seat of the pants flying” 25

26. 26

27. FFF-CRASH-SAR VISUAL ILLUSIONS
Defined as- False impressions or misconceptions of actual conditions
FFF-CRASH-SAR 27

28. VISUAL ILLUSIONS False Horizons-vertical/horizontal cues
Flicker Vertigo
Fixation/Fascination
Confusion with Ground Lights
Reversible Perspective
Altered Planes of Reference
Size-Distance Illusion
Height Perception (depth) 28

29. VISUAL ILLUSIONS Structural Illusion Autokinetic illusion
Relative Motion 29

30. VESTIBULAR ILLUSIONS Somatogyral Illusions Somatogravic Illusions
Leans
Graveyard Spin
Coriolis Illusion
Somatogravic Illusions
Oculogravic
Elevator
Oculoagravic 30

31. PREVENTION AND TREATMENT OF SPATIAL DISORIENTATION31

32. MIDDLE EAR DISCOMFORT Ear-helps regulate equilibrium During Flight
descents cause changes in pressure
rapid descents
After Flight
oxygen may cause delayed ear blocks
Prevention and Treatment
swallowing, yawning, valsalva
don’t fly with cold, sinus problems 32

33. QUESTIONS? 33