ahf 2203 aviation human factors presentation 8: orientation and motion sickness 1presented by mohd...

AHF 2203AVIATION HUMAN FACTORS

Presentation 8: Orientation and Motion Sickness

1Presented by Mohd Amirul for AMC

Presentation Outline

• Part 1 : Orientation

• Part 2 : Motion Sickness


Learning Outcomes• At the end of this session, student should be

able to:– Recognize the type of senses that involve leading

to several types of disorientation;– Identify the list measure to prevent several types

of disorientation.– Identify common causes of motion sickness and

the body areas that affected by motion sickness.– Recognize the necessary actions to be taken to

counteract the symptoms of motion sickness.


Part 1: Orientation

Presented by Mohd Amirul for AMC 4

Introduction• Orientation = aware with the relative position• Orientation is the key element in preventing aviation

accidents.• If the plane works, and the pilot is not impaired, then

the only other significant ingredient in safe flight for the trained pilot is maintaining orientation of the plane and himself.


1. Visual

2. Vestibular

3. Proprioceptive

ALL THREE SYSTEMS INTERGRATE TO FORM A COMPLETE MENTAL PICTURE

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Three Sensory Inputs for Orientations

Vision

Organs equilibrium located in the inner ears

Receptors located in the skin muscles, tendons and joins


• All three systems intergrate to form a complete mental picture

• Body Senses Which Assist in Maintenance of Balance / Equilibrium

• Vision is Most valid sense for maintaining orientation


WHAT IS DISORIENTATION?


What is disorientation?• Disorientation is lack of orientation or also can be

said as lack of awareness of the situation.• Disorientation also is an individual’s inability to

determine his position, attitude, and motion relative to Earth surface.

• Disorientation is a leading cause of more than 15 percent of reported accidents.

• When it occurs, pilots are unable to see, believe, interpret, or prove the information derived from their flight instruments.

• Instead, they rely on the false information that their senses provide.


Types of DISORIENTATIONThere are 5 types of DISORIENTATION, which are:1. Postural disorientation – related to proprioceptive

system 2. Positional disorientation – related to position3. Temporal disorientation – related to time4. Spatial disorientation – related to motion5. Vestibular disorientation – related to Vestibular

system6. Visual Illusion – related to Vision system


1. Postural disorientation • There are receptors within our skin, muscles,

tendons, and joints that detect changes in relative position, pressure, and up and down changes of our posture.

• Every time a muscle contracts or relaxes, tendons are pulled or released and joints move.

• Proprioceptive signals are those generated by these changes.

• All these inputs, which are continuously coming to the brain, tell the position of the pilot.

*tendon: organ that connect muscle and bone11Presented by Mohd Amirul for AMC

1. Postural disorientation • Posture also can be sensed by VESTIBULAR system

(Organs equilibrium located in the inner ears).• In flight, these signals can conflict and be confusing

to the mind, giving false interpretations and leading to DISORIENTATION.

• Acceleration causes a feeling of pressure in various parts of the body


2. Positional disorientation• Means the pilot is lost and doesn’t know his position

(disoriented).• Thus, he unable to take effective corrective action.

3. Temporal disorientation• Temporal means related to time.• It is direct function of how fast the brain process the

information


4. Spatial Disorientation • Spatial Disorientation is defined as illusions associated

with relative motion.• Spatial means how the pilot is oriented to the horizon as

either straight and level, in a turn, or climbing or descending (a visual orientation in a given space).

• Peripheral vision is the source to determine balance and orientation and will tell you how to react when you are

in motion.• It will mislead you into an illusion ofyour own motion.


5. Vestibular disorientation


5. Vestibular disorientation • Disorientation because of the Vestibular System not

functioning well.• The most severe and intense feeling of instability and

unbalance. • Can cause the Motion Sickness to the pilot, crew and

passengers.• When pilot experiencing vestibular disorientation, it is

called as VERTIGO.• Vertigo is the inability of a person to perceive his/her

position relative to the earth. In other words.... he/she cannot tell which way is UP!!!


Vestibular System

The Vestibular system is located in the inner ear. There are two related structures, which are:

1. Semicircular Canals: – Consists of three canals, Each canal is a bony, fluid-filled

structure.– Enlarged area containing a sensory structure.

2. Otolith Organs: – One of the particles in the inner ear. – It helps maintain equilibrium relative to the gravity.


AuditoryAuditoryNerveNerve

OtolithOtolith OrgansOrgans

Eustachian TubeEustachian Tube

Opening to ThroatOpening to Throat

OssiclesOssicles

Middle EarMiddle EarEar DrumEar Drum

External EarExternal Ear

CochleaCochlea

Semicircular CanalsSemicircular Canals

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Vestibular System


Vestibular System1. Semicircular Canals• Semicircular Canals is sensitive to angular

acceleration .• Angular acceleration is the change in both

speed and direction .• It detects yaw, pitch, and roll motions.

2. Otolith Organs• The Otolith organs is sensitive to linear acceleration and deceleration (forward,

aft, up, and down)• Linear accelerations is the change in speed

without a change in direction

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Semicircular canals

Otolith organ


Semicircular canals response to Roll, Pitch and Yaw


Vestibular disorientation will lead to Vestibular Illusions

Vestibular illusions is an inaccurate models of orientation.

There are four types vestibular illusions:a)Coriolis iIlusionb)Leans iIlusionc) Occulogravic illusiond)Rotational illusion

Illusion: False Belief22Presented by Mohd Amirul for AMC

a) Coriolis Ilusion• Coriolis – Circular motion of wind as it passes over a

rotating earth.• Coriolis illusion is caused by the sudden change to the VESTIBULAR system • It occurs due to aircraft angular acceleration that affect

the flow of fluids inside the semicircular canals.• It is dangerous illusion as it overwhelming sense of

disorientation.• Can occur in any phase of flight especially during the

beginning of turn for climb and descend.


a) Coriolis Illusion• If pilot turn his head in different

direction of aircraft turn, he will disoriented and confuses either aircraft were in a roll or yaw

• During a constant rate turn, if you tilt your head down, the rapid head movement puts the fluid in motion in more than one semicircular canal creating an overwhelming sensation of rotating, turning or accelerating along an entirely different plane.

• An attempt to stop the sensation by maneuvering the airplane may put it into a dangerous attitude.

• To avoid, do not move your head too fast in limited visibility or darkness.


b) Leans Illusion• Leans Illusion is the false

movement sense, can occurs when the pilot senses a bank angle when the aircraft is actually in level flight.

• The leans can easily occur if the pilot not pay attention to the cockpit instrument.


c) Occulogravic Illusion: A false sensation of climbing

• Oculogravic: in conditions of acceleration, sense of nose high or low and correction in pitch in a direction opposite the sensation.

• When an aircraft accelerates in level flight, the otolith organs sense a nose-high attitude, which cause the pilot to pitch the aircraft down. 26Presented by Mohd Amirul for AMC

d) Rotational Illusion

• Also called angular motion illusion.

• It caused by mis-information from a constant-rate turn (spin).

• The pilot will disorientated and unable to control his actions.

• Can cause the aircraft loss of control.


Aircraft Accidents due to Vestibular Orientation (VERTIGO)

• Flash Airlines Flight 604 dived into the Red Sea shortly after take off. All 148 people were killed.

• The captain had encountered vertigo (Vestibular disorientation), his control column was slanted to the right, and the captain did not notice.

• The 737 banked until it was unable to stay in the air.

• It is Egypt's worst air disaster.28Presented by Mohd Amirul for AMC

6) Visual illusions

• Visual illusions affect what the pilot perceives solely through vision, which in turn determines how he or she will respond.

• Illusions of this kind are a greater source of misguidance in a flying activity such as judging landing height and distances


Visual Illusions

1. Autokinesis – look at static source of light for a period of time in the dark.

2. False horizon - confusing bright stars and city lights. E.g: When Flying toward the water, because too dark , the lights along the shoreline seems like stars in the sky.

1. Oculogyral illusions 2. Oculogravic illusions3. Visual-cue illusions4. Fog and haze5. Water Refraction 6. Landing Visual Illusions

There are many different types of visual illusions that commonly occur at night. Staying aware of them is usually the best way to avoid them. THIS ILLUSION CAN LEAD TO FALSE MOVEMENT OF THE AIRCRAFT.


Autokinesis• Autokinesis: the perception of false movement of the aircraft

when the pilot stares at a distant and static object.

• Autokinesis is caused by staring at a single point of light against a dark background for more than a few seconds. After a few moments, the light appears to move on its own. To prevent this illusion, focus the eyes on objects at varying distances and avoid fixating on one target. Be sure to maintain a normal scan pattern.


False Horizon

• A false horizon can occur when the natural horizon is obscured or not readily apparent.

• It can be generated by confusing bright stars and city lights. It can also occur while flying toward the shore of an ocean or a large lake. Because of the relative darkness of the water, the lights along the shoreline can be mistaken for stars in the sky.


Oculogyral

• Oculogyral: at night with no horizon, of a condition in which a moving object in the distance, and seen in peripheral vision, is perceived to be stationary and pilot corrects in the opposite direction.


Oculogravic Illusions• Also called somatogravic illusions, these are

perceptions of tilt induced by stimulation of the otolith organs.

• From the visual perspective, the illusion to the pilot is either a climb or a descent when he has no visual reference to the horizon. With a climb, the eyes try to compensate with a downward tracking, as is common when flying through an updraft.

• This illusion is also called an elevator illusion. The opposite illusion, familiar in helicopter flight in an autorotation, is the intuitive response of the pilot to change direction and/ or altitude, which can decrease airspeed below a desired level.


Night Landing Illusions• Landing illusions occur in many forms. Above feature-less

terrain at night, there is a natural tendency to fly a lower-than-normal approach.

• Elements that cause any type of visual obscuration, such as rain, haze, or a dark runway environment also can cause low approaches.

• Bright lights, steep surrounding terrain, and a wide run-way can produce the illusion of being too low, with a tendency to fly a higher-than-normal approach.


• Often a set of regularly spaced lights along a road or highway can appear to be runway lights. Pilots have even mistaken the lights on moving trains as runway or approach lights. Bright runway or approach lighting systems can create the illusion that the airplane is closer to the runway, especially where few lights illuminate the surrounding terrain.


Size- Distance IllusionSize- Distance IllusionLarge Wide Runway

Narrow Runway

Am I too Low ?

Am I too High ?

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Preventionof Disorientation

• Prevention– Use visual clues from the horizon– Minimize head movement– Rely on instruments


Treatment Spatial Disorientation

• Treatment– Relax– Allow sensation to subside– Do not panic– Do not make rapid or sudden head movements– Rely on instruments


Correction for disorientation

• Pilots must trust the reliable information available to him INSTRUMENTS

• Disregard his own sensations


Part 2: Motion Sickness


Introduction

• Motion sickness occurs when man is exposed to real and unfamiliar motion.

• Normally experienced by training’s pilot or passengers.

• Pilot and passengers will feel uneasiness because a bit of anxiety, unfamiliarity.


Major Causes of Motion Sickness

• Motion sickness is caused by continued stimulation of the tiny portion of the inner ear (vestibular system) which controls your sense of balance/equilibrium.

• Several factors that can affect the vestibular system are: – When exposed to unfamiliar motion.– During turbulent weather

• Some of the other additional common causes include– Heart discomfort– Anxiety– Observing or smelling someone else who is airsick– Eating foods that are nauseating (disgusting).


Symptoms of Motion Sickness

• It causes nausea (tendency to vomit).• The symptoms are progressive. First, you lose your

desire for food. • Then saliva collects in your mouth and you begin to

sweat freely.• Eventually, you become nauseated and disoriented. • Your head aches and you may have to vomit. • Finally, can become incompletely incapacitated

(incapacitated: prevent from functioning in a normal way)


Prevention & Treatment

• Drink Enough Water• Use supplemental oxygen• Loosen tight fitting clothing• Limit head movement, avoid unnecessary

movement• Focus on a point outside of aircraft• If severe, cancel flight and landing aircraft


Conclusion

• For summarization disorientation is caused by:– Vestibular system not functioning well and

resulting to the false sensation to the pilot– Misinterpretation of visual information.

• Motion sickness occurs when man is exposed to real and unfamiliar motion. Normally experienced by training’s pilot or passengers because a bit of anxiety, unfamiliarity.


Key Points• Orientation• Sensory input for orientation• Disorientation• Types of Disorientation• Visual Illusion• Prevention of Disorientation• Treatment of Disorientation• Motion Sickness• Cause of Motion Sickness• Symptom of Motion Sickness• Prevention and Treatment of Motion Sickness.


Quiz 2: Vision1. List down FIVE important parts of the eye

and their function.2. States THREE types of vision and when it

commonly used.3. Name FOUR types of impairment in vision.4. State FOUR causes that could impaired your

vision.

Duration : 20 minutes


End of Presentation #85 Minutes for Q/A session


ahf 2203 aviation human factors presentation 8: orientation and motion sickness 1presented by mohd...

Documents

mohd amirul

postural disorientation

timespatial disorientation

motion relative

symptoms of motion sickness

systems intergrate

relative positionorientation

skin muscles