Aviation Physiology

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Aviation Physiology
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Roadmap

• Vision
• Night Flight
• Visual Illusions
• Landing Illusions
• Spatial Disorientation
• Hypoxia
• ADM (Aeronautical Decision Making)

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Quote of the Day

• IM SAFE

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Vision

• Vision
• result of light passing through the cornea and
  striking a lens.
• Retina
• Cones
• Rods

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Vision

• Cones
• perceive color and depth
• concentrated in the fovea
• Rods
• concentrated outside the fovea
• dim light and night receivers.
• 10,000 time more sensitive to light than cones
• Primary receptors to night vision and peripheral
  vision
• Night Blind spot
• Anatomical Blind spot

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Dark Adaptation

• Visual Purple (Rhodopsin)
• Light absorbing protein in membrane of rods
• Allows rods to detect images in the dark
• Night flight
• 30 minutes required for full adaptation to dark
• Red lights
• Rods least affected by red lights wavelength
• Minimal contraction of iris

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Night Flight Checklist

• Get dark adapted prior to flight
• Keep glasses and windscreen clean
• Look off to side 15o while scanning
• Close one eye if using bright light
• Properly use oxygen
• Quit Smoking
• Vitamin A
• Get adequate rest

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Visual Illusions

• False Horizons
• Black Hole Approach
• Landing Illusions

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Visual Illusions

• False Horizons
• Natural horizon is obscured or not apparent
• Attempting to realign yourself to false horizon
  can lead to a dangerous flight attitude
• Black Hole Approach
• Long, straight-in approach at night to a brightly
  lit runway over featureless and unlit terrain
• Pilot attempts to maintain visual angle

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Landing Illusions

• Sloping runways
• Runway width
• Terrain
• Weather conditions
• Visibility

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Illusions
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Approach Illusions
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Example Runway Width
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Sloping Runway
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Disorientation

• The incorrect mental image of your position,
  attitude, or movement
• Three sources of input
• Kinesthetic Sense
• Vision
• Vestibular System

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Kinesthetic and Vestibular

• Awareness of position obtained from the nerves in
  your skin, joints, and muscles.
• Fly by the seat of your pants
• Rely upon kinesthetic and vestibular senses in
  low visibility
• Problem UNRELIABLE
• Factors such as fatigue, high workload, alcohol,
  and anxiety add to susceptibility to
  disorientation and visual illusions.

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What Can I do?

• Rely on the instruments
• Regardless of how your body feels, maintaining
  orientation during flight at night or in marginal
  weather conditions is key.

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Illusions Leading to Disorientation

• Graveyard Spiral
• Turn Tightens as Pilot tries to raise nose
• Leans
• Desire to turn opposite direction after rolling
  out of a turn
• Inversion Illusion
• Abrupt change from climb to straight and level

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Hypoxia

• Oxygen deficiency in the bloodstream
• Symptoms
• Headache, fatigue
• Light headed or dizzy sensation, lethargic
• Tingling or warming sensations, sweating
• Sleepiness
• Cyanosis (discoloration of fingernails and lips)
• Euphoria
• Effects
• Lack of clear thinking
• After time, unconsciousness

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Hyperventilation

• Too much Oxygen
• Not enough Carbon Dioxide
• Symptoms
• Dizziness
• Hot and cold sensations
• Sleepiness
• Tingling of hands, legs, and feet
• Remedy
• Breathe into brown paper bag
• Talk Aloud

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ADM

• Systematic approach to the mental process used to
  determine best course of action
• Dangerous Tendencies
• Scud Running
• Continuing Visual Flight into IMC
• Neglect of Checklists

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Hazardous Attitudes

• Attitudes
• Antiauthority
• Impulsivity
• Macho
• Resignation

• Antidotes
• Follow the Rules
• Think first
• It could happen to me
• Im not helpless

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Any Questions?

• Aviation in itself is not inherently dangerous.
  But to an even greater degree than the sea, it
  is Unforgiving of any carelessness, incapacity,
  or neglect
• -Anonymous