2. Risk Assessment: Low
Safety Considerations: None
Environmental Considerations: None
Evaluation: You will evaluated on this block of
instruction during the 40 question Aeromedical
Review Exam

3. Terminal Learning Objective
ACTION: Manage the effects of
Spatial Disorientation
CONDITION: While serving as an
aircrew member
STANDARD: In accordance with The
Fundamentals of Aerospace
Medicine and FM 3-04.301

4. Enabling Learning Objective #1
ACTION: Identify the mechanisms of
equilibrium
CONDITION: Given a list
STANDARD: In accordance with The
Fundamentals of Aerospace
Medicine and FM 3-04.301

5. Mechanisms of Equilibrium
Visual
Vestibular
Proprioceptive

7. Enabling Learning Objective #2
ACTION: Identify the role of vision in
orientation
CONDITION: Given a list
STANDARD: In accordance with The
Fundamentals of Aerospace
Medicine and FM 3-04.301

8. Role of Vision
• Vision is the most reliable sense used
during flight
• 80% of orientation while flying is
dependent on the visual sense
Visual
Vestibular
Proprioceptive
80%
15%
5%

9. The visual system is one of three mechanisms
that integrate to form a complete mental picture
of one’s orientation (perception, recognition,
identification)
The system consists of two modes
Visual System
Focal (Central) vision =30 degrees
Ambient (Peripheral) vision = 175 degrees

10. Focal Vision
•Also called Central Vision
•Done consciously
•Presents us with clear view
•Allows us to view colors
•Determines distance and depth
perception

11. Ambient Vision
•Also called Peripheral Vision
•Done subconsciously
•Detects motion and attitude cues
•Helps to provide balance
•Poor acuity properties

13. Enabling Learning Objective #3
ACTION: Identify the visual illusions
CONDITION: Given a list
STANDARD: In accordance with The
Fundamentals of Aerospace
Medicine and FM 3-04.301

14. Visual Illusions
•False horizons
•Fascination/fixation
•Flicker vertigo
•Confusion with
ground lights
•Relative motion
•Altered planes of
reference
•Structural
•Height/depth perception
•Crater illusion
•Size distance
•Autokinesis
•Reverse perspective

15. False Vertical/Horizontal Cues
(False Horizon)
Occurs when the pilot subconsciously chooses
the wrong reference point for orientation

16. Fascination/Fixation
TARGET HYPNOSIS
TASK SATURATION

17. Target Hypnosis

18. Flicker Vertigo
Caused by sunlight flickering through rotor blades
Rotating beacons reflecting against an overcast
sky or against the windscreen

19. Confusion with Ground Lights
• Along seashores or rural areas
• Ground lights may be perceived as celestial lights
• Celestial lights may be perceived as ground lights

23. Falsely perceived self-motion in relation to
the real motion of another object
Relative Motion

24. Altered Planes of Reference
• Inaccurate sense of altitude, attitude,
or flight path
• Mountains / Valleys

26. Structural Illusion
The
phenomenon
in which
objects
become
distorted when
visual
obscurants
are present
such as rain,
snow, sleet, or
the curvature
of a wind
screen

27. Due to a lack of visual cues, the pilots
or crew members may perceive that
they are higher than they actually are

32. Crater Illusion
An illusion that the aircraft is landing into a hole/ crater or
on a upward slope, created when the search light is
positioned too far under the nose of the aircraft
Crater Illusion

33. Size- Distance Illusion
Large Wide Runway
Narrow Runway
Am I too
Low ?
Am I too
High ?
24
24

35. Autokinetic Illusion
Occurs when a static light appears to move
when it is stared at for several seconds

36. At night, an aircraft may appear to be going
away when it is actually approaching
Reversable Perspective

39. Enabling Learning Objective #4
ACTION: Identify the function of the
vestibular system
CONDITION: Given a list
STANDARD: In accordance with The
Fundamentals of Aerospace
Medicine and FM 3-04.301

40. Components of The Vestibular
System
• Located within the middle ear
• Semicircular Canals
• Otolith Organs

41. Functions of The Vestibular
System
• Visual tracking
• Reflex information
• Orientation without vision

42. Visual Tracking
Maintains focus of the retinal image

43. Reflex
Information

44. Orientation Without Vision

45. Functions Of The Semicircular
Canals
• Responsive to angular acceleration and
deceleration
• Change in both speed and direction
• Detects yaw, pitch,
and roll

46. Semicircular Canals
• Right angles to each other
• Contains endolymph fluid

47. Function Of The Otolith
Organs
• The Otolith organs are stimulated by
gravity and linear accelerations
• Change in speed without a change in
direction
• Sensitive to linear acceleration and
deceleration (forward, aft, up, and down)

48. Function of The Otolith Organs
FORWARD ACCELERATION FORWARD DECELERATION
FALSE SENSATION OF BACKWARD
UPRIGHT TILT FORWARD TILT BACKWARD
TRUE SENSATION TRUE SENSATION TRUE SENSATION

49. Function of The Otolith Organs

51. Enabling Learning Objective #5
ACTION: Identify the function of the
proprioceptive system
CONDITION: Given a list
STANDARD: In accordance with The
Fundamentals of Aerospace
Medicine and FM 3-04.301

53. Seat of Pants Flying
• Very unreliable means of orientation
• Dependent upon gravity and inertia
• Flying without reference to instruments

56. Enabling Learning Objective #6
ACTION: Identify the types of spatial
disorientation
CONDITION: Given a list
STANDARD: In accordance with The
Fundamentals of Aerospace
Medicine and FM 3-04.301

57. TYPE I - UNRECOGNIZED
TYPE II - RECOGNIZED
TYPE III - INCAPACITATING
Classifications of Disorientation

58. Unrecognized
Type I
• Pilot does not consciously perceive any
indication of Spatial Disorientation
• False inputs from sensory organs or cues
• Crashes with smile on their face
• Depth perception illusion
• Leans

59. Brownout

61. The Leans
• Pilot enter unperceived bank (sub-
threshold maneuver)
• Refers to instruments
• Corrects aircraft attitude
• Conflict between mechanisms of
equilibrium
• Pilot compensates by leaning in
original bank

62. Recognized
Type II
• Pilot consciously perceives a
problem, but may not know it
is due to spatial disorientation
• Pilot can correct the situation

63. • Pilot enters a turn stimulating one
semicircular canal
• Pilot makes a head movement in a
different geometric plane
• An additional semicircular canal is
stimulated
• Results in overwhelming sensation of
Yaw, Pitch, and Roll simultaneously
Coriolis

65. Incapacitating
Type III
• Pilot experiences overwhelming
sensations
• Conflict of sensory inputs
• Unable to properly orient themselves
by use of instruments or visual cues

66. Nystagmus
A rapid flickering motion of both eyes back and
forth, seriously degrading vision to 20/200 for a
few seconds

68. Enabling Learning Objective #7
ACTION: Identify the dynamics of
Spatial disorientation
CONDITION: Given a list
STANDARD: In accordance with The
Fundamentals of Aerospace
Medicine and FM 3-04.301

69. Dynamics Of Spatial
Disorientation
• Visual dominance
• Vestibular suppression
• Vestibular opportunism

70. Visual Dominance
A learned phenomenon where one incorporates
visual orientation information while excluding
other sensory cues (a very thorough cross-
check)
Example: Leans

71. Vestibular Suppression
• An active process of visually overriding
undesirable vestibular sensations
• In flight, pilot develops suppression via
repeated exposure to linear or angular
acceleration

72. Vestibular Opportunism
The propensity of the vestibular
system to fill any orientation
void swiftly

74. Enabling Learning Objective #8
ACTION: Identify the measures to
prevent spatial disorientation
CONDITION: Given a list
STANDARD: In accordance with The
Fundamentals of Aerospace
Medicine and FM 3-04.301

75. SD Prevention
• Instruments-trust your instruments
• Education and training
• Instrument proficiency
• Health
• Aircraft design
• Cockpit Organization

76. SD Prevention
• Never fly without visual
reference points
• Never stare at lights
• Dark adaptation
• Avoid self -imposed stresses
(DEATH)

78. Enabling Learning Objective #9
ACTION: Identify the actions to treat
spatial disorientation
CONDITION: Given a list
STANDARD: In accordance with The
Fundamentals of Aerospace
Medicine and FM 3-04.301

79. Treatment
• Refer to instruments, ensure they
read right
• Develop and maintain cross-checks
• Delay intuitive reactions
• Transfer controls
• Never fly both VMC and IMC at
the same time

80. Ensure the Instruments
Read Right

82. • Mechanisms of equilibrium
• Role of vision
• Visual illusions
• Function of Vestibular system
• Function of proprioceptive system
• Types of disorientation
• Dynamics of disorientation
• Prevention
• Treatment

83. Conclusion