Aeromedical FactorsAeromedical Factors

CW2 Steve JonesCW2 Steve Jones

ObjectiveObjective To develop the student Instructor To develop the student Instructor

Pilot’s understanding of the Pilot’s understanding of the Aeromedical Factors associated Aeromedical Factors associated with Army Aviation.with Army Aviation.

ReferencesReferences FM 1-301FM 1-301 AR 40-8AR 40-8 FM 1-240FM 1-240 AIMAIM

ScheduleSchedule Self-Imposed StressesSelf-Imposed Stresses HypoxiaHypoxia Spatial DisorientationSpatial Disorientation Visual IllusionsVisual Illusions Vestibular IllusionsVestibular Illusions

Self-Imposed StressesSelf-Imposed Stresses

RUGSRUGSXHAUSTIONXHAUSTIONLCOHOLLCOHOLOBACCOOBACCOYPOGLYCEMIAYPOGLYCEMIA

DDEEAATTHH

HypoxiaHypoxia

HypoxicHypoxic– lack of oxygen in the air lack of oxygen in the air

HypemicHypemic– oxygen carrying capacity of the bloodoxygen carrying capacity of the blood

StagnantStagnant– inadequate blood circulationinadequate blood circulation

HistotoxicHistotoxic– interference with the use of oxygeninterference with the use of oxygen

Types of Types of HypoxiaHypoxia

Hypoxia (con’t)Hypoxia (con’t)

IndifferentIndifferent– altitude 0 - 10,000 feetaltitude 0 - 10,000 feet

CompensatoryCompensatory– altitude 10,000 - 15,000 feetaltitude 10,000 - 15,000 feet

DisturbanceDisturbance– altitude 15,000 - 20,000 feetaltitude 15,000 - 20,000 feet

CriticalCritical– altitude 20,000 - 25,000 feetaltitude 20,000 - 25,000 feet

Stages of HypoxiaStages of Hypoxia

Spatial DisorientationSpatial Disorientation An individual's inaccurate An individual's inaccurate

perception of position, attitude, perception of position, attitude, and motion relative to the center and motion relative to the center of the earth.of the earth.

THE CONDITION MOST THE CONDITION MOST SUSCEPTIBLE TO SPATIAL SUSCEPTIBLE TO SPATIAL

DISORIENTATION IS --DISORIENTATION IS -- During a sudden and unexpected During a sudden and unexpected

transition from VMC to IMC flight transition from VMC to IMC flight conditionsconditions

SENSES OF BALANCESENSES OF BALANCE Visual SystemVisual System Vestibular SystemVestibular System Proprioceptive SystemProprioceptive System

VISUAL ILLUSIONSVISUAL ILLUSIONSwhich lead to landing errorswhich lead to landing errors

Runway Width IllusionsRunway Width Illusions Runway and Terrain Slope Runway and Terrain Slope

IllusionsIllusions Featureless Terrain IllusionsFeatureless Terrain Illusions Atmospheric IllusionsAtmospheric Illusions Ground Lighting IllusionsGround Lighting Illusions

VESTIBULAR SYSTEMVESTIBULAR SYSTEM

Semicircular CanalsSemicircular Canals Otolith OrgansOtolith Organs

SEMICIRCULAR CANALSSEMICIRCULAR CANALS Right angles to each otherRight angles to each other Contains endolymph fluidContains endolymph fluid

Vestibular IllusionsVestibular Illusions

LeansLeans Graveyard SpinGraveyard Spin Coriolis IllusionCoriolis Illusion

SomatogyralSomatogyral

MostMost common form of Spatial Disorientation common form of Spatial Disorientation

THE LEANSTHE LEANS

Motion is usually undetected during a subthreshold Motion is usually undetected during a subthreshold maneuver (less than 2maneuver (less than 2oo))

Pilot corrects attitude and compensates for the Pilot corrects attitude and compensates for the false sensation of turning in the opposite directionfalse sensation of turning in the opposite direction

This illusion seldom affects This illusion seldom affects both pilots at the same both pilots at the same timetime

CORIOLIS ILLUSIONCORIOLIS ILLUSION Pilot enters a turn stimulating one Pilot enters a turn stimulating one

semicircular canalsemicircular canal Pilot makes a head movement in a Pilot makes a head movement in a

different geometrical planedifferent geometrical plane Stimulating a 2nd / 3rd semicircular canal Stimulating a 2nd / 3rd semicircular canal Results in overwhelming sensation of Results in overwhelming sensation of

Yaw, Pitch, or Roll Yaw, Pitch, or Roll

THE CORIOLIS ILLUSION

The most deadly illusionThe most deadly illusion

SOMATOGRAVIC ILLUSIONSOMATOGRAVIC ILLUSION

Illusions created by the Otolith organs Illusions created by the Otolith organs as a result of linear accelerationas a result of linear acceleration

FUNCTION OF THE OTOLITH ORGANS

FORWARD ACCELERATION CENTRIFUGAL /CENTIPUAL FALSE SENSATION OF BACKWARD FALSE SENSATION OF UPRIGHT

UPRIGHT TILT FORWARD TILT BACKWARDTRUE SENSATION TRUE SENSATION TRUE SENSATION

ELEVATOR ILLUSIONELEVATOR ILLUSION Occurs during sudden upward accelerationOccurs during sudden upward acceleration Pilot perceives a nose up attitudePilot perceives a nose up attitude Tendency to “nose over” aircraftTendency to “nose over” aircraft

OCULOAGRAVICOCULOAGRAVIC

Upward movement of the eyes during Upward movement of the eyes during weightlessness, caused by rapid weightlessness, caused by rapid downward motion of the aircraftdownward motion of the aircraft

UPRIGHT

UPRIGHT

EXTREMEAFT TILT

AFT TILT

NOSE HIGH NOSE HIGH SENSATIONSENSATION

OCULOGRAVIC ILLUSIONOCULOGRAVIC ILLUSION

ConclusionConclusion

Questions?Questions?