Spatial Disorientation

Question 1

Two types of Vestibular Illusions:

Answer 1

• Somatogyral illusions- (semicircular canals) (pitch, roll, yaw) (angular acc/dec)
• Somatogravic illusions- (otolith organ) (gravity and linear acc/dec)

Question 2

Describe three types of somatogyral illusions:

Answer 2

Leans- Most common, feels straight and level, but attitude indicator shows slight bank.

Graveyard spin/spiral- Usually occurs in fixed wing, pilot enters spin for several seconds, semicircular canals reach equalibrium (no motion perceived), so pilot will maintain spin.

Coriolis illusion- Most dangerous, overwhelming disorientation- prolonged turn with rapid head motion can cause pitch, roll, and yaw movement in semicircular canals resulting in head over heels tumbling sensation. Must transfer controls.

Question 3

Describe three types of somatogravic illusions:

Answer 3

• Oculogravic- during rapid accel/decel the pilot will sense nose up or nose down. Pilot may over control attempting to correct -extreme nose high/low. Does not occur with sufficient outside references.
• Elevator illusion- Upward acceleration (updraft) will cause the eyes to track down attempting to fixate, pilot will sense nose up. Disoriented pilot may push the nose down making it worse.
• Oculoagravic- Downward acceleration (downdraft or can occur when entering auto’s), opposite of elevator illusion, during descent eyes will track up attempting to fixate, pilot will sense nose low. A disoriented pilot may pull the acft into a nose high attitude intensifying illusion.

Question 4

Three types of sensory systems:

-Vestibular system: (define)

Answer 4

• Inner ear detects motion and gravity.

- (semicircular canals)/(Otolith organs)