AHF 2203 AVIATION HUMAN FACTORS

AHF 2203 AVIATION HUMAN FACTORS
Presentation 8: Orientation and Motion Sickness Presented by Mohd Amirul for AMC

Presented by Mohd Amirul for AMC
Presentation Outline Part 1 : Orientation Part 2 : Motion Sickness Presented by Mohd Amirul for AMC

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. Presented by Mohd Amirul for AMC

Part 1: Orientation Presented by Mohd Amirul for AMC

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. Presented by Mohd Amirul for AMC

Three Sensory Inputs for Orientations
1. Visual Vision 2. Vestibular Organs equilibrium located in the inner ears 3. Proprioceptive Receptors located in the skin muscles, tendons and joins ALL THREE SYSTEMS INTERGRATE TO FORM A COMPLETE MENTAL PICTURE Presented by Mohd Amirul for AMC 6

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 Presented by Mohd Amirul for AMC

WHAT IS DISORIENTATION?
Presented by Mohd Amirul for AMC

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. Presented by Mohd Amirul for AMC

Types of DISORIENTATION
There are 5 types of DISORIENTATION, which are: Postural disorientation – related to proprioceptive system Positional disorientation – related to position Temporal disorientation – related to time Spatial disorientation – related to motion Vestibular disorientation – related to Vestibular system Visual Illusion – related to Vision system Presented by Mohd Amirul for AMC

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 bone Presented 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 Presented by Mohd Amirul for AMC

2. Positional disorientation 3. Temporal 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 Presented by Mohd Amirul for AMC

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 of your own motion. spatial disorientation defines illusions or perceived positions associated with relative motion, often called vection illusions. Vection: relative motion to the eyes between the body and external object, often an illusion of motion Furthermore, spatial implies a visual orientation in a given space: how the pilot is oriented to the horizon as either straight and level, in a turn, or climbing or descending Presented by Mohd Amirul for AMC

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!!! Otolith Organs: Monitor linear acceleration Located in same bony labyrinth as semicircular canals Composed of sensory hairs Hairs project into a membrane containing crystalline particles Gravity causes particles to bend hair cells Presented by Mohd Amirul for AMC

Vestibular System The Vestibular system is located in the inner ear. There are two related structures, which are: Semicircular Canals: Consists of three canals, Each canal is a bony, fluid-filled structure. Enlarged area containing a sensory structure. Otolith Organs: One of the particles in the inner ear. It helps maintain equilibrium relative to the gravity. Presented by Mohd Amirul for AMC

Vestibular System Semicircular Canals Otolith Organs Cochlea Auditory Nerve Ossicles Ear Drum Middle Ear External Ear Eustachian Tube Presented by Mohd Amirul for AMC Opening to Throat 18 19 18 19

Vestibular System 1. 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 Semicircular canals Otolith organ Otolith organs Stimulated by linear acceleration: A change in speed without a change in direction Presented by Mohd Amirul for AMC 19 26 19 26

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: Coriolis iIlusion Leans iIlusion Occulogravic illusion Rotational illusion Illusion: False Belief Presented 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. Most severe vestibular illusion occurs when the semicircular canal fluid flows in two planes of rotation simultaneously The aircraft must be turning Rapid head movement Presented by Mohd Amirul for AMC

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. Presented by Mohd Amirul for AMC

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. Presented by Mohd Amirul for AMC

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 or decelerates in level flight, the otolith organs sense a nose-high attitude relative to gravity If that sensation is acted upon by the pilot without cross-checking instruments, he might pitch the aircraft down. Deceleration causes a similar sensation of a nose-low attitude. When an aircraft accelerates in level flight, the otolith organs sense a nose-high attitude, which cause the pilot to pitch the aircraft down. Presented 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. Also called angular motion illusion, rotational illusions result from misinformation from a constant-rate turn, as in a spin. If the turn is at a constant rate, the fluid in the canals returns to its original stable position of equilibrium. This results in the pilot’s perception that the turn has stopped. When the turn slows (a change as in acceleration) or the aircraft levels off, the fluid is once again displaced but this time in the opposite direction. The “graveyard spiral” is a condition most likely to affect fixed-wing aircraft pilots. Upon recovering from the turn (or spin in this case) as just described, the pilot will undergo deceleration, which will be sensed by the canals and interpreted as a spin or turn in the opposite direction. A loss of altitude in a prolonged constant rate turn may be interpreted as a wings level descent, which can lead you to increase elevator back pressure and tighten the turn, increasing your altitude loss. A recovery to wings level flight may produce the illusion that the airplane is in a turn in the opposite direction, resulting in a reentry of the spiral. This feeling must be fought until the fluid in your semicircular canals quits moving again. The pilot’s instruments will tell him that he is not spinning, but he will have a strong sensation that he is. If there is no outside reference to the horizon and the pilot disregards or doesn’t believe the instruments, he will be tempted to make control corrections against the falsely perceived spin so that he reenters a spin in the original direction. Often the conflict is noticed, but the sensory input, even though erroneous, is overpowering, and the pilot is unable to control his actions. This action is compounded by the pilot’s noting a loss of altitude as the spin develops and applying back pressure on the controls and adding power in an attempt to gain altitude. This tightens the spin to the point where recovery is nearly impossible. In a graveyard spiral, the angular velocity is in the form of a coordinated turn rather than a spin. Remaining in this turn long enough (perceived as a constant-rate coordinated turn), that sensation of turning will be lost, and the flight will continue as a spiral. A proper recovery from a spin that has ceased stimulating the motion sensing system can crate the illusion of spinning in the opposite direction. The disorientated pilot will return the aircraft to its original spin Presented by Mohd Amirul for AMC

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. Flash Airlines Flight 604 was a charter flight operated by Egyptian charter company Flash Airlines. On 3 January 2004, the Boeing crashed into the Red Sea shortly after takeoff from Sharm el-Sheikh International Airport, killing all 142 passengers, many of them French tourists, and all 6 crew members. The findings of the crash investigation are controversial, with accident investigators from the different countries involved not agreeing on the cause. Presented 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 Presented by Mohd Amirul for AMC

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 – look at static source of light for a period of time in the dark. 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. Oculogyral illusions Oculogravic illusions Visual-cue illusions Fog and haze Water Refraction Landing Visual Illusions NIGHT VISUAL ILLUSIONS There are many different types of visual illusions that commonly occur at night. Anticipating and staying aware of them is usually the best way to avoid them. 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. Autokinesis is the perception of false movement when a static source of light is looked at by the pilot for a period of time (minutes) in the dark (Fig. 8-12). This moving reference point (an illusion) could lead the pilot to visually follow it. It is felt that the cause is the brain’s and eyes’ attempts to find some other point of reference in an otherwise featureless visual field. Prevention is a combination of realizing the eyes must focus on other objects at varying distances, not fixating on one target, and basic scanning. 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: 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. Oculogyral illusions This effect was previously described under disorientation. From the visual point of view, this illusion is more apparent at night, when vision is already compromised. The pilot perceives the apparent movement of a distant object in the visual field as a result of stimulation of the semicircular canals; therefore, in the early stages of a turn to the left, for example, the target appears to move rapidly to the left. After the turn is established and then stopped, the target object appears to move in the opposite direction, to the right. The pilot might not correct her aircraft accordingly unless she is scanning her instruments and confirming that she is tracking a moving illusion. 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 light-ing systems can create the illusion that the airplane is closer to the runway, especially where few lights illuminate the surrounding terrain. Presented by Mohd Amirul for AMC

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. Presented by Mohd Amirul for AMC

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. Presented by Mohd Amirul for AMC

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. Presented by Mohd Amirul for AMC

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. Presented by Mohd Amirul for AMC

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. Presented by Mohd Amirul for AMC

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. Presented by Mohd Amirul for AMC

Size- Distance Illusion
Am I too Low ? Large Wide Runway 24 Narrow Runway The effect of runway width on the pilot’s image of runway (left) and potential effect on the approach flown (right). Accustomed width during a normal approach (top). A narrow runway makes the pilot feel higher, so he or she flies the approach too low and flares too late (center). A wide runway gives the illusion of being closer than it actually is, so the pilot tends to approach too high and flares too soon (bottom). Am I too High ? 24 Presented by Mohd Amirul for AMC 37

Prevention of Disorientation
Use visual clues from the horizon Minimize head movement Rely on instruments Presented by Mohd Amirul for AMC

Treatment Spatial Disorientation
Relax Allow sensation to subside Do not panic Do not make rapid or sudden head movements Rely on instruments Presented by Mohd Amirul for AMC

Correction for disorientation
Pilots must trust the reliable information available to him  INSTRUMENTS Disregard his own sensations Presented by Mohd Amirul for AMC

Part 2: Motion Sickness Presented by Mohd Amirul for AMC

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. Presented by Mohd Amirul for AMC

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). Presented by Mohd Amirul for AMC

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) Presented by Mohd Amirul for AMC

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 Presented by Mohd Amirul for AMC

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. Presented by Mohd Amirul for AMC

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. Presented by Mohd Amirul for AMC

Quiz 2: Vision List down FIVE important parts of the eye and their function. States THREE types of vision and when it commonly used. Name FOUR types of impairment in vision. State FOUR causes that could impaired your vision. Duration : 20 minutes Presented by Mohd Amirul for AMC

End of Presentation #8 5 Minutes for Q/A session

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