Spatial Disorientation

Question 1

What is spatial disorientation?

Answer 1

The pilot’s erroneous perception of position, attitude, or motion in relation to the gravitational vertical and the Earth’s surface

Question 2

What sensory systems to we rely on to be able to properly orientate?

Answer 2

Visual
Vestibular
Somatosensory

Question 3

What are some countermeasures and SD mitigation?

Answer 3

Understand risk factors through pre mission planning
Good aircrew coordination
Do not attempt visual flight below established weather mins or in areas with deteriorating conditions
Trust your instruments, develop a good cross check

Question 4

How many types of SD are there?

Answer 4

3
Type I (Unrecognized)
Type II (Recognized)
Type III (Incapacitating)

Question 5

What is Type I SD?

Answer 5

It’s when an aviator does not perceive any indications of SD or necessarily think anything is wrong. Other senses will work to corroborate what the aviator sees and feels.

This is the MOST dangerous type

Question 6

What is Type II SD?

Answer 6

The pilot is aware there is a problem, but may not recognize it as SD

Question 7

What is Type III SD?

Answer 7

The pilot experiences such an overwhelming sensation of movement that they cannot physically orient using visual cues of the aircraft instruments

Question 8

How does the visual sensory system work with SD?

Answer 8

Visual system is the most important sensory in maintaining the ability to orient and move in a 3D space. With this, we use ambient vision to focus on large areas and focal vision for items in our central field

Question 9

How does the vestibular system work with SD?

Answer 9

Can provide relatively accurate orientation, but not in a dynamic flight environment

Question 10

What are the organs associated with the vestibular system?

Answer 10

The inner ear organs; semicircular canals and otolith organs

Semicircular canals detect angular acceleration while otolith organs detect linier accelerations

Question 11

How does the somatosensory system work with SD?

Answer 11

Reacts to tactile sensations resulting from forces or pressure on the skin, joints, tendons, and muscles

“seat of your pants”

Question 12

What are the visual illusions?

Answer 12

False Horizon
Fascination
Confusion with Ground Lights
Vection
Height Depth Perception
Crater Illusion
Structural Illusion
Size Distance Illusion
Size Constancy
Shape Constancy
Aerial Perspective
Autokinesis

Question 13

What is vection?

Answer 13

Falsely perceiving motion of oneself when no physical motion is actually occurring, like when you are stopped at a red light and another car pulls next to you

Question 14

What is false horizon illusion?

Answer 14

When you confuse a wide sloping plane of reference with the true horizon

Question 15

What is confusion with ground lights?

Answer 15

When you mistake the ground lights for stars, particularly isolated ground lights

Question 16

What is height-depth perception?

Answer 16

This is due to absent/insufficient visual cues, which causes you to misjudge the aircrafts true altitude

Question 17

What is crater illusion?

Answer 17

When landing at night with NVDs and the IR light is too far under the aircrafts nose. Creates the illusion of landing in sloping terrain, resulting in continuing to lower the collective and prematurely impact the ground

Question 18

What is structural illusion?

Answer 18

Caused by the effects of rain, snow, sleet or other visual obscurations, causing a straight line to appear curved

Question 19

What is size-distance illusion?

Answer 19

Misinterpreting the size and shape of an unfamiliar object by comparing it to what they are accustomed to

Question 20

What is size constancy?

Answer 20

Common example is landing at an unfamiliar runway. A skinnier runway may cause the pilot to think they are higher a further away, resulting in them landing low and short

Question 21

What is shape constancy?

Answer 21

This deals with things like a sloping runway. An upsloping runway may make the pilot think they are too high, causing the pilot to adjust to get the correct sight picture

Question 22

What is aerial perspective?

Answer 22

This deals with size and clarity. Mistaking short or stunted trees for taller ones will cause the pilot to misjudge altitude form the ground. Or if the environment is hazy, objects appear further away

Question 23

What is autokinesis?

Answer 23

Occurs predominately at night. After fixating on a light for 6-12 seconds it can appear to move up to 20*, making a pilot think a fixed object is actually in motion

Question 24

What are the three types of vestibular illusions?

Answer 24

Somatogyral, somatogravic, oculoagravic

Question 25

What are somatogyral illusions?

Answer 25

They give a false sensation of rotation and occur due to the semicircular canals inability o accurately register sustained angular velocity There are the leans, graveyard spiral, coriolis illusion, and post roll illusion

Question 26

What are the leans?

Answer 26

It is an illusion of bank and occurs when a false sensation of angular displacement around the roll axis. If a pilot rolls into a long sustained turn, she may perceive that the aircraft is flying straight and level. Once detected, they pilot may level the aircraft but they will feel as though they are banking the opposite direction This is the most common vestibular illusion

Question 27

What is the graveyard spiral?

Answer 27

When entering a moderate or steep turn for several seconds, the fluid in the semicircular canals will reach equilibrium and no motion will be perceived. Upon quickly recovering from the bank, the semicircular canals will undergo angular deceleration and have a strong sensation to initiate a bank in the opposite direction. This can be worsened by a perceived loss in altitude causing the pilot to pitch up

Question 28

What is the coriolis illusion?

Answer 28

Occurs during prolonged turns, when a pilot makes a head motion away from the plane of rotation, such as moving your head to adjust the radio in a DVE

Question 29

What is the post roll illusion?

Answer 29

After a roll maneuver, with the absence of a visible horizon, a pilot may initiate a roll rate into a coordinated turn, complete the maneuver, but then incorrectly provide control input to add additional bank in the same direction thinking they decreased the roll rate

Question 30

What are somatocravic illusions?

Answer 30

Changes in gravity or linear acceleration stimulate the otolith organs, resulting in a false sensation of body tilt There is the g-excess illusion, elevator, and acceleration/deceleration

Question 31

What is the acceleration/deceleration illusion?

Answer 31

During linear acceleration, the otolith organ may sense a nose high attitude. In a DVE, this may cause the pilot to pitch the nose downward

Question 32

What is the g-excess illusion?

Answer 32

This deals with the change in G magnitude, of sustained Gs >1. If you move your head during this acceleration, you may think you are in a bank

Question 33

What is elevator illusion?

Answer 33

With upward or downward acceleration, a false sensation of pitch may be perceived. An increase in Gs, drives the eyes down, giving a sensation of climbing, causing the pilot to pitch the nose down

Question 34

What is oculoagravic illusion?