Spatial disorientation

Question 1

Vertigo:

Answer 1

A spinning sensation usually caused by a peripheral vestibular abnormality in the ear.

Question 2

Types of spatial disorientation:

Answer 2

• Type I: Unrecognized (most dangerous)
• Type II: Recognized
• Type III: Incapacitating

Question 3

Three types of sensory systems:

Answer 3

• Visual: Provides 80% of orientation
• Vestibular:
  
  • Otolith organs: gravity, linear accel/deceleration
  • Semicircular canals: angular acceleration, roll/pitch/yaw
• Proprioceptive: sensors in joints, muscle, and skin. “Seat of pants”

Question 4

Visual illusions:

Answer 4

• F: Fascination/fixation- Fasc-IN-ation inside cockpit, fixation- outside
• F: False horizons- chosing wrong reference point for orientation
• F: Flicker vertigo- flickering lights cause distorted sensations
• C: Confusion with ground lights- perceived as celestial or vise versa
• R: Relative motion- falsely perceived self motion
• A: Altered planes of reference- wrong sense of altitude, attitude,etc
• S: Structural- Objects become distorted due to visual obscurants
• H: Height/depth perception- lack of cues, acft seems higher than it is
• C: Crater- feeling of landing in a hole, caused by searchlight
• A: Autokinesis- static lights appear to move after staring at them
• R: Reversible perspective- acft appears to be going away when approaching
• S: Size-distance: false perception of distance from an object due to misinterpretation of its size.

Question 5

Vestibular illusions:

Answer 5

• Somatogyral

- Somatogravic

Question 6

Somatogyral- Semicircular canals:

Answer 6

• Leans: failure to perceive angular motion
• Gravyard spin: equillibrium, no preceived motion
• Coriolis illusion: intense sensation of tumbling (most dangerous)

Question 7

Somatogravic- Otilith organs:

Answer 7

• Oculogravic: accel/decel = nose high illusion
• Elevator: vertical up/down = nose high illusion
• Oculoagravic: vertical down = nose low illusions

Question 8

Prevention of spatial disorientation:

Answer 8

• Never fly VMC and IMC
• Never fly without visual reference points
• Avoid certain stressors: (Fatigue, hypoxia, anxiety, smoking, hypoglycemia)
• Trust instruments

Question 9

Treatment of spatial disorientation:

Answer 9

• D: Delay intuitive reaction
• I: Incorporate a good cross check
• R: Refer to instruments
• T: Transfer controls

Question 10

Spatial disorientation:

Answer 10

Inability to determine one’s position, attitude, and motion relative to the surface of the earth.