Risk Assessment: LowRisk Assessment: Low

Safety Considerations: NoneSafety Considerations: None

Environmental Considerations: NoneEnvironmental Considerations: None

Evaluation: You will evaluated on this block of instruction during the 40 question Aeromedical Review Exam

Terminal Learning ObjectiveTerminal 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

Enabling Learning Objective #1 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

Mechanisms of EquilibriumMechanisms of Equilibrium

Visual

Vestibular

Proprioceptive

Enabling Learning Objective #2Enabling 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

Role of VisionRole of Vision• Vision is the most reliable sense used Vision is the most reliable sense used

during flightduring flight• 80% of orientation while flying is 80% of orientation while flying is

dependent on the visual sensedependent on the visual sense

VisualVestibularProprioceptive80%

15%

5%

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 SystemVisual System

Focal (Central) vision =30 degrees

Ambient (Peripheral) vision = 175 degrees

Focal VisionFocal Vision

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

Ambient VisionAmbient Vision

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

Enabling Learning Objective #3 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

Visual IllusionsVisual 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

False Vertical/Horizontal Cues(False Horizon)

False Vertical/Horizontal Cues(False Horizon)

Occurs when the pilot subconsciously chooses

the wrong reference point for orientation

Occurs when the pilot subconsciously chooses

the wrong reference point for orientation

Fascination/FixationFascination/Fixation

TARGET HYPNOSISTARGET HYPNOSIS

TASK SATURATIONTASK SATURATION

Target HypnosisTarget Hypnosis

Flicker VertigoFlicker Vertigo

Caused by sunlight flickering through rotor blades

Rotating beacons reflecting against an overcast

sky or against the windscreen

Confusion with Ground LightsConfusion with Ground Lights

• Along seashores or rural areas

• Ground lights may be perceived as celestial lights

• Celestial lights may be perceived as ground lights

• Along seashores or rural areas

• Ground lights may be perceived as celestial lights

• Celestial lights may be perceived as ground lights

Falsely perceived self-motion in relation to

the real motion of another object

Relative MotionRelative Motion

Altered Planes of ReferenceAltered Planes of Reference

• Inaccurate sense of altitude, attitude, or flight path

• Mountains / Valleys

• Inaccurate sense of altitude, attitude, or flight path

• Mountains / Valleys

Structural IllusionStructural Illusion

The phenomenon in which objects becomedistorted when visual obscurants are presentsuch as rain, snow, sleet, or the curvature of a wind screen

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

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

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

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 IllusionCrater Illusion

Size- Distance IllusionSize- Distance IllusionLarge Wide Runway

Narrow Runway

Am I too Low ?

Am I too High ?

24

24

Autokinetic IllusionAutokinetic Illusion

Occurs when a static light appears to move

when it is stared at for several seconds

Occurs when a static light appears to move

when it is stared at for several seconds

At night, an aircraft may appear to be going At night, an aircraft may appear to be going away when it is actually approachingaway when it is actually approaching

Reversable PerspectiveReversable Perspective

Enabling Learning Objective #4Enabling 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

Components of The Vestibular System

Components of The Vestibular System

• Located within the middle ear• Semicircular Canals• Otolith Organs

Functions of The Vestibular System

Functions of The Vestibular System

• Visual tracking

• Reflex information

• Orientation without vision

Visual TrackingVisual Tracking

Maintains focus of the retinal image

Reflex Information

Reflex Information

Orientation Without VisionOrientation Without Vision

Functions Of The Semicircular Canals

Functions Of The Semicircular Canals

• Responsive to angular acceleration and deceleration

• Change in both speed and direction • Detects yaw, pitch, and roll

Semicircular CanalsSemicircular Canals

• Right angles to each other• Contains endolymph fluid

Function Of The Otolith Organs

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)

Function of The Otolith OrgansFunction of The Otolith Organs

FORWARD ACCELERATION FORWARD DECELERATION FORWARD ACCELERATION FORWARD DECELERATION FALSE SENSATION OF BACKWARD FALSE SENSATION OF BACKWARD

UPRIGHT TILT FORWARD TILT BACKWARD UPRIGHT TILT FORWARD TILT BACKWARDTRUE SENSATION TRUE SENSATION TRUE SENSATIONTRUE SENSATION TRUE SENSATION TRUE SENSATION

Function of The Otolith OrgansFunction of The Otolith Organs

Enabling Learning Objective #5Enabling 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

Seat of Pants FlyingSeat of Pants Flying

• Very unreliable means of orientation

• Dependent upon gravity and inertia

• Flying without reference to instruments

Enabling Learning Objective #6Enabling 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

TYPE I - UNRECOGNIZED

TYPE II - RECOGNIZED

TYPE III - INCAPACITATING

Classifications of DisorientationClassifications of Disorientation

UnrecognizedType I

UnrecognizedType 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

BrownoutBrownout

The LeansThe 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

RecognizedType II

RecognizedType II

• Pilot consciously perceives a problem, but may not know it is due to spatial disorientation

• Pilot can correct the situation

• Pilot consciously perceives a problem, but may not know it is due to spatial disorientation

• Pilot can correct the situation

• 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

CoriolisCoriolis

IncapacitatingType III

IncapacitatingType III

• Pilot experiences overwhelming sensations • Conflict of sensory inputs

• Unable to properly orient themselves by use of instruments or visual cues

NystagmusNystagmusA rapid flickering motion of both eyes back and

forth, seriously degrading vision to 20/200 for a

few seconds

Enabling Learning Objective #7Enabling 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

Dynamics Of Spatial Disorientation

Dynamics Of Spatial Disorientation

• Visual dominance

• Vestibular suppression

• Vestibular opportunism

Visual DominanceVisual Dominance

A learned phenomenon where one incorporates visual orientation information while excluding other sensory cues (a very thorough cross-check)

Example: Leans

Vestibular SuppressionVestibular Suppression

• An active process of visually overriding undesirable vestibular sensations

• In flight, pilot develops suppression via repeated exposure to linear or angular acceleration

Vestibular OpportunismVestibular Opportunism

The propensity of the vestibular system to fill any orientation

void swiftly

Enabling Learning Objective #8Enabling 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

SD PreventionSD Prevention

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

SD PreventionSD Prevention

• Never fly without visual reference points

• Never stare at lights

• Dark adaptation

• Avoid self -imposed stresses (DEATH)

Enabling Learning Objective #9Enabling 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

TreatmentTreatment

• 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

Ensure the Instruments Read Right

Ensure the Instruments Read Right

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

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

ConclusionConclusion