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

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

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

Mechanisms of Equilibrium Visual Vestibular Proprioceptive

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

Role of Vision Vision is the most reliable sense used during flightVision is the most reliable sense used during flight 80% of orientation while flying is dependent on the visual sense80% of orientation while flying is dependent on the visual sense Visual Vestibular Proprioceptive 80% 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 System Focal (Central) vision =30 degrees Ambient (Peripheral) vision = 175 degrees

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

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

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

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

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

Fascination/Fixation TARGET HYPNOSIS TASK SATURATION

Target Hypnosis

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

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 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 Motion

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

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

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 Crater Illusion

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

Autokinetic 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 away when it is actually approaching Reversable Perspective

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

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

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

Visual Tracking Maintains focus of the retinal image

Reflex Information

Orientation Without Vision

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

Semicircular Canals Right angles to each other Contains endolymph fluid

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 Organs FORWARD ACCELERATION FORWARD DECELERATION FALSE SENSATION OF BACKWARD UPRIGHT TILT FORWARD TILT BACKWARD TRUE SENSATION TRUE SENSATION TRUE SENSATION

Function of The Otolith Organs

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

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

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

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

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

Brownout

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

Recognized Type 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 Coriolis

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

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

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

Dynamics Of Spatial Disorientation Visual dominance Vestibular suppression Vestibular opportunism

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

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

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

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

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

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

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

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

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

Conclusion