1、1,Airline Transition Course,ATP Chapter 17 Aeromedical Factors,2,Aeromedical Factors,3,Hypoxia,Hypoxia is a state of oxygen deficiency in the body sufficient to impair functions of the brain and other organs.,4,Types of HypoxiaHypoxic Hypoxia,Lungs are not getting enough oxygen to deliver. Causes: B

2、reathing air at reduced barometric pressure. Strangulation Severe Asthma Breath holding Hypoventilation Malfunctioning oxygen equipment at altitude.,5,Hypoxic (Altitude) Hypoxia,There is not enough oxygen molecules available to breath with sufficient pressure. As we climb the pressure decreases ther

3、efore the number of available oxygen molecules also decreases. Hypoxic symptoms do not begin to become evident until about 5,000 especially at night.,6,Types of HypoxiaHypemic Hypoxia,Transportation of Oxygen is reduced. Causes: Drugs (nitrites and sulfanilamides) Chemicals (carbon monoxide and cyan

4、ide) Heart Failure Shock Acceleration (Gs) Postural Changes Tourniquets,7,Hypemic (Anemic) Hypoxia,Blood is not able to carry the available oxygen. Anemia, or a reduced number of healthy, functioning red blood cells for any reason, means less capacity for blood to carry oxygen. Occurs most commonly

5、is the form of carbon monoxide poisoning.,8,Carbon Monoxide Poisoning,Hemoglobin physically carries 75 times more oxygen molecules than can be absorbed in the oxygen solution. Hemoglobin accepts carbon monoxide 250 times more than oxygen. This reduces the bloods ability to carry oxygen.,9,Carbon Mon

6、oxide Poisoning,Symptoms include: Headache Drowsiness dizziness,10,Stagnant Hypoxia,Another form of Hypemic Hypoxia. The bloods ability to carry oxygen is reduced due to the stagnated flow of blood. This is caused by the heart failing to pump effectively, an artery constricting and cutting off or re

7、ducing the flow, and venous pooling of blood due to gravity, such as varicose veins.,11,Types of HypoxiaHistotoxic Hypoxia,Body is not able to utilize oxygen. Causes: Carbon monoxide Cyanide Alcohol,12,Histotoxic Hypoxia,Histotoxic means the cell expecting and needing oxygen is abnormal and unable t

8、o take up oxygen. This is caused by toxins absorbed by the cell. This can occur when alcohol is present in the blood or in the cell and prevents the use of oxygen by the cell. This is caused by alcohol, narcotics and some poisons.,13,Stages of Hypoxia,Indifferent Stage Up to 10,000 Compensatory Stag

9、e From 5,000 to 15,000 Disturbance Stage From 10,000 to 20,000 Critical Stage Above 12,000,14,Indifferent StageUp to 10,000,Vision especially night vision can start to deteriorate at altitudes less than 5,000 In a normal body night vision is lost 5-10% at 5,000. 15-25% at 10,000 25-30% at 12,000,15,

10、Compensatory StageFrom 5,000 to 15,000,The body and mind can be severely affected and in increasing and subtle ways. In this stage however the circulatory and respiratory systems compensate for the reduced availability of oxygen. This happens as a result of increased heart rate, enhanced circulation

11、, and a more productive cardiac pumping of blood. Breathing rate and depth also increases.,16,Disturbance StageFrom 10,000 to 20,000,Symptoms begin to become severe including: Headaches Hyperventilation Impaired peripheral vision Marked fatigue Sleepiness Euphoria,17,Critical StageAbove 12,000,Can h

12、appen as fast as 3-5 minutes after the beginning of the compensatory or disturbance stages. At this point you become unconscious and run the risk of central nervous system failure and convulsions.,18,Hypoxia SymptomsBody,Loss of vision Peripheral Night Acuity Focus Weakness in muscles Fatigue Sense

13、of touch and pain are diminished Headache Lightheadedness or dizziness Tingling Muscular coordination decreased Stammering Cyanosis Altered respiration,19,Hypoxic SymptomsMind,Impaired judgment Loss of self-criticism Overconfidence Overly aggressive Depression Reaction time decreased Euphoria,20,Fac

14、tors Affecting HypoxiaSelf-Imposed,Physiological altitude is the altitude which the body feels. The presence of self-imposed factors can raise your physiological altitude. 1 ounce of alcohol equals 2,000 Smokers are at about 3,000 to 5,000 Your body will deal with low oxygen levels better if youre i

15、n good shape.,21,Factors Affecting HypoxiaEnvironmental,Acclimatization If you live at high altitude you will be less susceptible to hypoxia. Rate of Ascent The faster the ascent the worse off you will be. Duration of Exposure Symptoms are time related. Physical Activity Increased activity can incre

16、ase effects of hypoxia. Temperature The body has to use valuable oxygen to cool, or heat itself.,22,Effective Performance Time,EPT is the time from when the oxygen was taken away to the time the pilot can take action, for instance putting on oxygen. EPT can be further reduced in a rapid decompressio

17、n, by 1/3 or .,23,Treatment of Hypoxia,If there is any suspicion of hypoxia in yourself or a crewmate, the immediate use of 100% oxygen is essential. If no supplemental oxygen is available then immediately get the airplane below 10,000. Hypoxia is a valid reason to declare an emergency.,24,Hypervent

18、ilation,Hyperventilation results from an abnormal increase in the volume of breathing. The result is an excessive amount of carbon dioxide being removed from the body. A stressful situation can cause anxiety which can lead to hyperventilation.,25,HyperventilationSymptoms,26,shortness of breathbreath

19、lessnesschest tightness deployed on commercial aircraft in 1993. Intended as a backup to air traffic control. Entirely air-based; no ground equipment Two variants: TCAS I Required for aircraft w/ 30 seats. TCAS II Required for aircraft w/ 30 seats.,36,TCAS Advisories,TCAS monitors all transponder-eq

20、uipped aircraft within four nautical miles. Traffic Advisories TCAS I & II Alert pilot of potential for conflict within 40 sec. Resolution Advisories TCAS II Only Alert pilot of potential for conflict within 20 sec. Provide vertical guidance to escape conflicts.,37,Example Conflict Scenario,Ownship(

21、TCAS II Equipped),Intruder(TCAS II Equipped),Conflict,Conflict,DESCEND, DESCEND,TRAFFIC, TRAFFIC,CLEAR OF CONFLICT,TRAFFIC, TRAFFIC,CLIMB, CLIMB,CLEAR OF CONFLICT,38,Maintaining Aircraft Separation,Air Traffic Control (ATC) Monitors all aircraft in a given service area. Resolves traffic conflicts we

22、ll in advance. TCAS Activates when conflict is imminent (1 min). Visual Identification Ineffective when visibility is poor.,39,TCAS Dependability Properties,Safety Resolution advisories must not bring the aircraft into greater harm. TCAS must not create conflicts where none would have existed otherw

23、ise. Reliability TCAS must be able to endure an entire flight without requiring service (10-18 hours).,40,SafetyBad Guidance,Intruder-Terrain Service Ceiling Multiple Intruders,Service Ceiling,41,SafetyFalse Advisories,TCAS might detect a false conflict if it receives bad transponder data. it receiv

24、es bad local flight data. If TCAS issues a false RA, a conflict might occur if the RA is followed. Limited time for ATC to detect & intervene How does the pilot know who to follow?,42,Summary,TCAS helps prevent midair collisions by supplementing air traffic control. TCAS is an imperfect solution. Ba

25、d guidance False conflicts Aircraft have been saved both from following and disobeying TCAS RAs.,43,TITLE: BASIC AVIATION PHYSIOLOGY TIME: 37 MINUTES RATED: G,44,Scanning Technique,45,Scanning,Scanning procedures for effective collision avoidance should constitute looking outside for 15 seconds then

26、 inside for 5 seconds on a repeating basis (ATP Handbook) In the daytime scan 10 degree increments focusing near and far. About 3 seconds per increment. At night, one should scan for traffic slowly to permit off-center viewing (ATP Handbook),46,The Eye,Rods Work better at night Black and white Detec

27、t peripheral movement Around the sides of the eye Cones Color Vision In the center of the eye Needs lots of light to energize,47,Visual Illusions,Autokinesis can occur in the dark when a pilot stares at a stationary light for a period of time with the result that the light appears to move about. (AT

28、P),48,Related Illusions,Coriolis illusion describes the effect of a prolonged constant-rate turn under IFR conditions followed by an abrupt head movement which creates the illusion of rotation about a different axis (ATP.) Somatogravic illusion may occur during a rapid acceleration takeoff and creat

29、es the illusion that the airplane is in a nose-up attitude (ATP.),49,Illusions Leading to Landing Errors,A narrower than usual runway can create the illusion that the airplane is at a higher than actual altitude.,50,Illusions Leading to Landing Errors,When landing over darkened or featureless terrai

30、n, such as water or snow, a pilot may be susceptible to the illusion that the airplane appears to be at an altitude higher than it actually is, which would result in a hard landing. (ATP),51,Illusions Leading to Landing Errors,Haze can create the illusion that the airplane is farther from the runway

31、 than it actually is.,52,Illusions Leading to Landing Errors,Sudden penetration of fog can lead to the perception of pitching up.,53,Illusions Leading to Landing Errors,Rain on the windscreen can create the illusion of being at a higher than actual altitude.,54,Are we going to hit it?!,If an aircraf

32、t ahead appears to be stationary in the windshield it is a collision threat.,55,SPATIALDISORIENTATION,56,THREE SENSORY SYSTEMS,VISION VESTIBULAR SYSTEM SOMATOSENSORY SYSTEM,57,LEARNING TO FLY,USE BASIC ORIENTATION USE ALL AVAILABLE SENSES OUTSIDE REFERENCES INSTRUMENT REFERENCES,58,VISION,90% of ori

33、entation Most reliable sense Instrument/visual flight elements SCAN! Interpretation Aircraft control Even reliable vision can be fooled “Optical illusions”,59,CAN YOU READ THIS?,60,WHICH LINE IS LONGER?,61,DO YOU SEE THE GRAY?,62,WHAT DO YOU SEE?,63,WHAT DO YOU SEE?,64,HOW OLD IS SHE?,65,THE DANCING ELEPHANT,66,AVIATION-RELATEDVISUAL ILLUSIONS,Featureless terrain False horizons Ground lighting Autokinesis Runway width illusion Runway slope illusion,67,AVIATION-RELATEDVISUAL ILLUSIONS,Terrain elevation Atmospheric illusions Rotorwash drift (helicopters) Waterfall (helicopters) Brown/White