Human Factors Flashcards
What is haemoglobin?
Iron rich pigment which transports oxygen
What colour cells main function is to carry oxygen around the body?
Red blood cells
What is the vascular system made up of?
Blood vessels forming arteries, capillaries and veins
Being seated for a long time, how can you improve circulation?
Contracting and relaxing your diaphragm as well as elf and buttock muscles
What two respiratory processes occur in the lungs?
Energy giving oxygen breathed in, diffused through thin walls of lungs and into the blood.
Carbon dioxide returned to lungs and breathed out
What two respiratory processes occur in body’s tissues?
Oxygen is brought to body by red blood cells
Carbon dioxide, waste product from burning of carbohydrates carried away in bloodstream
What occurs as we gain height?
Air thins with fewer molecules in the same volume.
Percentage of components remains the same (78 nitrogen, 21 O2, 1other)
Total air pressure falls with altitude as does partial pressure of each of gasses
What is the international standard atmosphere?
Sea level temp 15C Lapse rate -2C per 1000ft Freezing level 7500ft Sea pressure 1013.2 Tropopause 36080 Temp at tropopause -56C
What are the three major effects of altitude on the human body brought about by pressure changes?
Lower external pressure causes gases in body to expand
Lower O2 pressure causes hypoxia
Dissolved gases come out of solution due to decreased external pressure
At what height is atmospheric pressure halved?
18000ft
At what height is oxygen partial pressure halved?
9000 ft
What is hypoxia?
When oxygen concentration in tissues is less than normal
What causes hypoxia?
Lack of O2 in the air
Partial pressure of O2 is too low
Inability of blood to carry O2 due to medical condition or carbon monoxide poisoning
What happens to air pressure and density as altitude increases?
They decrease
What happens to oxygen intake in the lungs with less dense air?
Lower mass of oxygen taken into the lungs with each breath
What are the symptoms of hypoxia?
Euphoria False sense of security Clumsy Difficulty concentrating Moody Drowsy Indecision Giddiness Headache Cyanosis (blue) fingernails and lips Increased pulse rate Increased rate and depth of breathing
Above what height is oxygen required?
10000ft
At what height will night vision start to deteriorate?
4000ft
How long should you wait to fly after donating blood?
24 hours
What are the times of useful activity ?
Alt. Moderate. Minimal 18000ft, 20mins. 30mins 22000ft. 5mins 10mins 25000ft. 2 mins. 3mins 28000ft. 1min. 1.5mins 30000ft. 45s. 1.25mins 35000ft. 30s. 45s 40000ft. 12s. 15s
What is likely to be affected by barotrauma on ascent?
Teeth and intestines
What is likely to be affected by barotrauma on descent?
Ears and sinuses
Blockage of what will cause pressure to be higher on the outside of the ear?
Eustachian tube
When is decompression sickness likely to occur?
When you fly after scuba diving
Why does decompression occur?
When certain gases such as nitrogen are absorbed into the blood under pressure
How long should you wait after diving to fly?
4 hours after dive not requiring decompression
12 hours after dive of less than 4 hours requiring stops
48 hours after dive greater than 4 hours requiring stops
What does hyperventilation do?
Flushes carbon dioxide out of blood and disturbs its chemical balance
What are symptoms of hyperventilation?
Light headed Numbness Tingling lips, finger and toes Palpitations Increased pulse rate Sweating Chest pain Blurred vision Dizziness Fainting
How do you treat hyperventilation?
Try and calm person
Allocating simple tasks to distract them
Slowing breathing rate
If carbon monoxide is suspected, what is your first course of action?
Turn the cabin heat off then open a fresh source of air
What are symptoms of carbon monoxide poisoning?
Headache Dizziness Nausea Impaired judgement Slower breathing rate Cherry red complexion
How long is the class one medical valid for?
Period of not more than 12 months
How long is a class two valid for?
4 years if under 40 or 2 if 40 or over
How long can you be sick for before requiring a check with a dame?
7 days for class 1 30 days class 2
What are some disqualifying illnesses?
Heart attack Stroke Diabetes Kidney stones Ulcers
What is the most common cause of inflight incapacitation?
Gastroenteritis
What can cause gastro?
Improperly prepared meal
Impure drinking water
How long should you not fly after gastro?
At least 72 hours
What is coronary thrombosis?
Blood clots obstructing flow of blood to the heart
What is myocardial infarction?
Also known as heart attack
Death of heart tissue
What is angina?
Reduced blood flow that deprives part of the heart of oxygen
Felt as pain in the chest neck shoulders and arms
What is atherosclerosis?
Blocking of the arteries by fats
What is an aneurism?
Bursting of an artery
What is a stroke?
Interruption of blood flow to some part of the brain
What are cardiovascular risk factors?
Family history Smoking High blood pressure Obesity Diabetes Stress
What is presbyopia?
Short sighted ness
What is gout?
Result of excess uric acid in the blood that crystallises in the joints. Especially toes, feet, ankles or fingers
What are haemorrhoids?
Anal varicose veins caused by prolonged sitting, constipation and consequent forced defacation
How long should exercise be to be effective?
Minimum of 20 minutes at least three times a week
In temperatures greater than 30C, how much water should we drink and how often?
250ml every 30 minutes
As a general rule, how long should you wait after alcohol?
8 hours however after heavy drinking, alcohol may be present up to 24 hours later
At sea level,what effects does smoker feel?
As hypoxia as non smoker at 8000 feet
What is the cornea?
Transparent cap over the lens which light rays first pass
It is curved and some refraction occurs
What is the iris?
Located between cornea and lens
Coloured membrane
What happens to the lens as we get older?
Becomes less flexible and less able to modify curvature
Aka presbyopia
What is the retina?
Light sensitive layer at the back of the eye
Screen onto which lens focuses images and converted into electrical signals that pass along optic nerve to brain
Where are the rods and cones located?
In the retina
What are cones responsible for?
Sensitive to colour, details and distant objects
Most effective in daylight
What are rods responsible for?
Sensitive to movement
Only see in black, white and shades of grey
Effective in both day and night
Responsible for peripheral vision
Where are cones located?
Central section of retinas, especially in foveal region opposite lens
Where are rods located?
Outside central foveal area
What is empty field myopia?
Natural tendency of eyes to focus in range of one to two metres
What is a blind spot?
Small area on retina where nerve fibres from rods and cons on retina lead into optic nerve
What is myopia?
Shortsightedness
Eye is relaxed and cornea and lens focus rays from a distant object not on retina but in front of it
See near objects fine but not distance objects
What is hyperopia?
Long sightedness
Seeing distant objects fine but not near objects
What is astigmatism?
Curvature of cornea is not perfectly round
How much percentage of light should sunglasses transmit?
10-15% and should filter out uv rays
Why should polarised sunglasses not be used?
May produce total loss of vision
How can you avoid empty field myopia?
Focus on available distant objects
What is autokinesis?
Visual illusion at night if you stare continuously at a single light against dark background. It will appear to move.
How can you guard against autokinesis?
Maintaining movement of your eyes in normal scanning
Monitoring instruments
A runway that slopes up will give you what illusion?
You will feel high and attempt to make a shallower approach
A runway that slopes down will give what impression?
Give the impression low and make a higher/steeper approach
What illusion does a narrow runway give?
That you are too high and you may delay the flare and land harder
What illusion does a wide runway give?
Being too low and you may hold off flare
What illusion does black hole approach give?
That you are higher than you think resulting in urge to fly down
Descent should be 5times ground speed for 3degrees approach
What three areas are in the ear?
Outer, middle and inner ear
Where are the three bones known As ossicles located?
Middle ear
What is the cochlea?
Converts mechanical energy from ossicles into electrical signals
What is tinnitus?
Excessive noise damaging the hairs in the cochlea and infection or injury causing damage to auditory nerve
Possible ringing in the ears
What above what db do you need hearing protection?
80db
At what db does noise become uncomfortable/painful?
120/130
What is presbycusis?
Loss of hearing due to increasing age
Ear plugs can reduce noise by how many db?
20-40 db
What makes up spatial orientation?
Visual 80%
Balance 10%
Seat of pants 10%
How is gravity detected?
Sensory hairs in a sac filled with gelatinous material known as otolithic organ or utricle
What does the otolith organ do with regards to g forces?
Detects them but doesn’t know its origin (direction)
What does the vestibular apparatus do?
Sense angular acceleration
Recognises change in rotary motion due to lag of viscous fluid
Bends sensory hairs
When are you likely or encounter “the leans?”
Slowly letting the wing drop then rapidly roll wings level
What is the somatogravic illusion?
Sensation of nose rising as you accelerate
Greater the acceleration the greater the feeling
How can you avoid airsickness?
Anticipate and avoid area of turbulence Eat lightly before hand Focus on horizon Avoid manoeuvres with unusual g force Ventilate cabin with fresh cool air
Above what g force produces physiological symptoms?
3.5
Wen will a grey out occur?
3.5-4.5 g
What are the two types of stressors?
Acute - immediate and disappears after a short time
Chronic - long lasting and fatiguing
What is the body’s comfortable humidity range?
40-60%
What is the comfortable temperature?
About 20degrees
What are some symptoms of fatigue?
Lack of awareness Diminished motor skills Obvious tiredness Slow reactions Short term memory problems Channeled concentration (fixation) Easily distracted
How does the brain process information?
Stimulation Perception Analysis Action Feedback Correction
What are our sense organs?
Eyes, ears, nose, taste buds
What are our receptors?
Skin and muscles
How long are sounds remember for?
About 5 seconds
How long are visual items stored for in the sensory memory?
About 1 second
How do we improve short term memory?
Rehearse it or encode it
How many items can the short term memory store and for how long?
About 7 items for about 15 seconds
What is aircraft control law formula?
Configuration + power + attitude =flight path + speed
What are the pilots primary control selections?
Attitude (pitch and bank)
Direction
Thrust
Configuration
What are our performance references?
Track (course)
Airspeed and ground speed
Rate of climb/descent
Altitude
What two tasks does the pilot in command have?
Be in control of aircraft
Be in command of situation
The degree of control skills formula is?
Natural attributes + discipline + training + recent experience = level of skill and resulting operating standards
What are the different awareness that encompass situational awareness?
Geographic Climatic Temporal Systems Self
What external factors affect pilots mind?
Environment
Ergonomics
Culture
What are some examples of expected threats?
Anticipated/expected/known threats
Thunderstorms, windshear, intense traffic in terminal area
What are some examples of unexpected threats?
Inflight malfunction
What are some examples of latent threats?
Equipment design issues, optical illusion, shortened turn around schedules
What are some examples of environmental threats?
Weather (thunderstorms, turbulence, icing, crosswind, temperatures)
ATS (traffic congestion, ATC error, language difficulty, ATS non standard phrases, runway change)
Airport (short runway, faded signs/markings, birds, construction)
Terraign (slope, lack of visual references, black hole
Operational pressures (delays, late, equipment changes)
Aircraft malfunction
What are some examples of organisational threats?
Flight attendant error Maintenance ever/error Ground handling event or error Dispatch error Documentation error Crew scheduling error
What are threats.
Events or errors that occur beyond the influence of the flight crew, increase operational complexity
What are errors?
Actions or inactions by flight crew that lead to deviation from organisational or flight crew intentions or expectations
What are some examples of errors?
Mis setting an altitude (spontaneous and independent of threat)
Missing a checklist item due to radio interruption (induced by threat)
Iced pitot leading to airspeed error leading to incorrect pilot actions (link in chain of errors)
What are the three categories of errors?
Aircraft handling
Procedural
communication
What are some examples of aircraft handling errors?
Altitude, track or speed deviations, exceeding airspeed limitations, incorrect attitude, heading or power settings, wrong flap/speed brake or undercarriage setting
What are some examples of procedural errors?
SOPs (failure to cross check settings/clearance limits)
Checklists (wrong challenge/response, items missed, late)
Briefings (omitted/incorrect)
Documentation (incorrect weight and balance or CoG, incorrect fuel calculations/quantity, ATIS, incorrect logbook or maintenance release entries,
What are some examples of communication errors?
Missed calls, misinterpretation of instructions, incorrect read back, incorrectly stated or misread clearance
What are the three undesired aircraft states categorised as?
Aircraft handling
Ground navigation
Incorrect aircraft configuration
What are aircraft handling states?
Aircraft control (attitude or heading deviation) Altitude, track or speed deviations Unnecessary weather penetration Unauthorised airspace penetration Exceeding aircraft limitation Non stable approach
What are ground navigation states?
Taxing to wrong taxiway
Exceeding taxi speed
Positions on wrong taxi way/ramp/gate or holding point
What are incorrect aircraft configurations?
Incorrect system configuration Incorrect flight controls configuration Incorrect autopilot mode or value Incorrect navaid or gps setting Incorrect power setting Incorrect fuel quantity or distribution Incorrect loading
