Human Factors Flashcards
At what temperatures is the body most comfortable in?
21-27 degrees
What humidity is human body most comfortable in?
40-60%
What temps can heat stress and cold stress take place?
Heat >32 degrees
Cold less than 10
What is the early indication of dehydration?
Drying of nasal passage
Prickly sensation of eyes
How long a period should be spent on the ground after making a blood donation?
24 hours
What is barotrauma?
Ear drum buldges inwards
Eustachian tube blocked
Pressure higher outside the ear then inside it
When is barotrauma likely to occur?
High rates of descent
What are some additional affects of barotrauma?
Burst ear drum
Pressure vertigo
What can relieve effects of barotrauma?
Valsalve Manoeuvre
What does Valsalve manoeuvre do?
Forces air to enter the eustachian tube to increase pressure in middle ear cavity, allowing it to become equal to outside pressure
If you have suffered an injury, what should you do?
Cease all flying
Notify DAME immediately
When should flying stop when pregnant?
After the 6th month
How can pilots assist airsick passengers?
Flying as smoothly as possible
Limiting the degree and rate of attitude changes (especially in pitch)
What can obesity lead to?
Hypertension, gout, diabetes, heart disease
What is the most common cause of pilot incapacitation in flight?
Gastro
How much water do you lose on average a day? What about on a hot day?
1 L average day
5 L hot day
What can the ingestion of too much salt lead to?
Hypertension
What sort of foods release more gas?
Green vegetabes
What can too little iron lead to?
Anaemia
Losing hearing as a result of age is likely to be affected in which frequency?
High frequency
The Eustachian tube links what part of the ears?
Middle ear to throat
During a descent with blocked Eustachian Tubes, what happens to the gas volume in the middle ear?
It decreases
What is the lowest temp at which signs of heat stress are likely to occur?
32 degrees
How long is a medical certificate valid for a ppl for student and private licences?
4 years for both if under 40
2 years if over 40+
How long is a medical certificate valid for CPL or higher?
1 year
When is another medical exam required ?
At the end of the period for re-issue of certificate
What is the majority of alcohol broken down by?
The liver
What is the average rate of alcohol broken down?
1 standard drink per hour for a man
Less than for a woman
How long can alcohol be present in the brain cells after drinking?
24 hours
What is CASA’s requirement for alcohol before a flight?
Total abstinence by pilot from any alcohol for a period of 8 hours before departure of aircraft
What is the maximum recommended standard drinks in one week for a man and woman?
21-28 for man
14-21 for woman
What is the general recommended period away from flying if on antibiotics?
24 hours
What are the symptoms of hyperventilation caused by?
Reduction of acidity of the bloody due to loss of C02
What are the symptoms of hyperventilation?
Lightheadedness Dizziness Sweating Rapid heart beat Tingling (hands or feet) Numbness (hands or feet)
How should hyperventilation be treated?
Make a conscious effort to slow down rate of breathing
By what height has atmospheric pressure halved?
18000 feet
What is the recommended rest after a scuba dive not requiring decompression stops?
4 hours at sea level
What is the recommended rest after a scuba dive which requires decompression stops but is less than 4 hours?
12 hours at sea level
What is the recommended rest after a scuba dive which requires decompression stops but is more than 4 hours?
48 hours
What is a side effect of antihistamines?
May induce drowsiness
If necessary to take sleeping tablets, how long a period should be waited before flying?
24 hours
At a depth of about 30 feet, what is the underwater pressure compared to sea level atmospheric pressure?
2 times normal sea level
What is decompression sickness caused by?
Dissolved nitrogen from the blood during rapid ascent from deep water
When suffering from an upper respiratory tract infection, what is a pilot likely to suffer from?
Pressure vertigo
When can analgesics be used?
Only for short term pain relief
What are the two functions of the ear?
Hearing
Balance
What is the function of the outer ear?
Canal which prevents intrusions (dust, insects etc) and protects eardrum from heat/cool
What does the ear drum do?
Forms an airtight seal protecting middle ear from contamination
What happens to sound?
Eardrum vibrates to sound waves arriving via the canal.
Hammer, anvil and stirrup amplify and conduct those vibrations to the cochlea
What does the stirrup connect and do?
Connects to the cochlea at the ‘oval window’
Mechanical energy of vibration begins conversion to electrical energy of nerve impulese
How is sounds carried to brain?
Via the cochlear nerve
What is the purpose of the Eustachian tube?
Vents atmosphere to/from middle ear to equalise pressure either side of ear drum
What does the cochlea do?
Processes vibrations arriving at oval window
Converts them to electrical signals and send to brain as nerve impulses via cochlea nerve
Where are the semi circular canals?
Mounted above cochlea in inner ear
What does semi circular canals do?
Detect acceleration in pitch, roll and yaw (sense of balance)
What is the cochlea filled with?
Fluid called Endolymph
Tiny hair like cells
What is in the semi circular canals?
Endolymph
Hair like cells (cupula)
What does cupula respond to?
Initial change in angular acceleration only (turning or rolling)
What organ senses linear acceleration?
Otolith organs
What organ senses angular acceleration
Semi circular canals
What is the otolith organ made up of?
Utricle and saccule
What does the utricle and saccule do?
Utricle lies horizontally and detects horizontal accelerations
Saccule lies vertically and detects vertical accelerations
What is the dominant organ in maintaining a sense of balance?
Eyes
At what intensity will prolonged exposure cause temporary or permanent damage to the ear?
85dB
At what intensity will exposure cause ear pain?
140dB
At what intensity will exposure cause ear discomfort?
120dB
As a rough guide, hearing protection should be worn if you have to yell to be heard from a distance of?
Half a metre
What does a decibel measure?
Intensity or loudness of a sound
What does a Hertz measure?
The frequency or pitch of a sound
Which part of the ear is most affected by pressure differences when eustachian tube is blocked?
Middle ear
If the eustachian tube is blocked, where is the blockage likely to occur?
At the bottom where the tube enters the nasal passage
Which component of the inner ear senses changes in speed with constant direction?
Otholith organ
Which part of the ear acts as a linear accelerometer?
Otolith
What is the function of the hammer, anvil and stirrup?
Transfer vibrations from ear drum to inner ear
What does the cornea do?
Transparent film though which light first enters the eye
Protects rest of eye from outside world
Helps lens focus light onto retina
What is the cornea supported and held in shape by?
Aqueous humour
What is the iris?
Coloured part of the eye
Changes shape in response to intensity of the light
Where are rods and cones found?
Interior surface of the retina
Where are cones located and what do they do?
Centrally located
Colour perception and fine detail
What sort of lighting is required by the cones?
Bright lighting
Where are the rods and what do they do?
Arranged concentrically around the cones
Responsible for night vision
What sort of lighting is required by rods?
Best in low light
Are rods sensitive to light or colour?
Light
How does the eye adapt to different lighting?
Adjusting the iris to change the diameter of the pupil by chemical changes in the light sensitive cells on the retina
Where is the most sensitive area on the retina?
The fovea
What is the fovea used for?
Fine details
What is the blind spot?
Junction of the optic nerves
What happens to light falling on the blind spot?
Will not be registered by the brain
What is the ‘priming’ substance for dark adaptation?
Rhodopsin
How long does rhodopsin take to reach its full concentration?
30 to 40 mins
How can you assist focus at night?
Look slightly to ones side of the object so light is focused onto rods and not the cones
Prolonged exposure to strong glare can cause what to night vision?
30 to 50% reduction in night vision for up to one week
What colour lighting has almost no effect on process of dark adaptation of rods?
Red light
What is flicker vertigo?
Bright light flickering when passing through an IDLING prop blade. Can also be induced by strobe light in cloud
When can empty field myopia occur?
Flying at high altitude or above unbroken layer of cloud when there is nothing to focus on
What is the resting distance of the eye?
1-2 m
How can empty field myopia be countered?
Occasionally focussing on wingtips, cloudtops or ground features
What are refractive errors>
Abnormalities in the lens that can usually be fixed with glasses
What is hyperopia?
Longsightedness
Distant objects seen clearly but closer objects fall behind retina
How can hyperopia be corrected?
Convex lenses
What is myopia?
Shortsightedness
Near objects seen clearly but distant objects fall short of retina
How can myopia be corrected?
Concave lenses
What is astigmatism?
Irregularities in the cornea and/or lens causing distortion of objects
How can astigmatism be corrected?
Cylindrical lenses
What is presbyopia?
Natural deterioration of eyes due to ageing .
Lens becomes less flexible
If on a collision course, what will another plane look like?
Remain stationary on the windscreen
What is saccades?
Eyeballs moving in a series of little jerks taking about 0.3s
How is it best to scan?
Move head about 10-15 degrees at a time
At what height can night vision deteriorate?
4000ft AGL
What is the function of the ciliary muscle in the eye?
Alter the shape of the lens to allow the eye to focus on objects at various distances
When light passes through the lens it is brought to focus at the back of the eyeball on the?
Retina
Where is the blind spot?
Junction of the optic nerve and retina
What is the maximum distance at which a healthy eye in good light could ID a circle 1m in diameter?
2nm
What affect would heavy rain do to objects viewed through window?
Appear further away then they actually are
Night vision is enhanced by looking slightly off centre, why is this?
Concentration of rods in the retinal periphery
Which part of the eye focuses the visual image onto the retina?
Lens
The eye adapts to changes in light by adjusting what?
Iris to change shape of the pupil and making chemical changes in the retina
Light is focused onto the retina by what?
Cornea and the lens
What is the Coriolis Illusion?
Pilot moving head forward during turn creating differing signals from semicircular canals
Creates tumbling sensation
What is the autokinetic illusion?
Focusing on single light against dark background, appears to be moving
What is the somatogravic illusion?
Acceleration mistaken for steep climb
On a super clear day, what can the incorrect impression be on final?
Objects closer then they actually are and you are overshooting
On a foggy day, what may the incorrect assumption be on final?
You are too low (i.e.undershooting)
What can a build up of water on the windscreen do to approach?
Make angle to runway threshold appear steeper then it is (may think overshooting)
What is the illusion landing on a wider then normal runway?
Believe you are lower then normal
Round out and hold off too high
What illusion will there be landing on a narrower runway?
Illusion that too high
Late round out and heavy landing
What is the illusion for terrain sloping up from threshold?
Pilot feels too low
Tendency to remain high, arrive at runway too high and/pr fast
What is the illusion for terrain sloping down from thershold?
Pilot feels too high
Tendency to fly lower and flatter approach requiring extra power on final
What is the illusion if runway is sloping up?
Appear to be too high
Flatter approach
What is the illusion if runway is sloping down?
Appear too low
Higher approach and overshoot/overspeed
On a clear night, what illusions can there be with the lights?
Lights appear closer then they are
Impression approach is too high
On a hazy/foggy night, what illusions can there be with the lights?
Lights appear further away
Impression approach is too low
What effect does black hole effect give?
Too high causing undershoot
What physical things can increase disorientation?
Head colds
Flu
Sinus infection
Exhaustion/discomfort
What mental things can increase disorientation?
Anxiety Stress Mental fatigue Fear/panic Preoccupation with other tasks
What does the proprioceptive system generate sensation from?
Skeletal muscles, joints and tendons
When viewed from the cockpit, what will a small town approx 5nm away seem?
Closer then it actual is on dark night
On a long wide runway which slopes down to landing threshold, what illusion may occur?
Low on approach
Tendency to overshoot
On a approach to land at night overwater approach, pilot may perceive what?
Runway closer then actually is
Approach too high causing undershoot
What sort of approach is likely to be made on a shorter then normal runway?
Approach too low
When will the average person experience grey out?
3.5 G
What is grey out?
Low O2 levels leading to partial loss of vision
Peripheral vision to fade
Still conscious
When does blackout occur?
5 G
What is black out?
Vision becomes black
Conscious but can still see
What is GLOC?
Loss of consciousness
What factors can decrease tolerance to G loads?
Hypoglycaemia (low blood sugar)
Heat stress
Hypoxia
Respiratory infection
What are some techniques for improving G tolerance?
More reclined seat
Tensing stomach muscles
Being physically fit
Does grey out and black out occur in negative g manoeuvres?
No
What is red out?
High sustained negative G
Force bottom eyelid over the eyeball
What is the most likely immediate effect of negative G?
Rupturing of small blood vessel of face and eyes (bloodshot eyes and red blotches on face)
What is the safe negative G limit?
-3G
What engine is carbon monoxide more present?
Piston engines
What does carbon monoxide do?
Enters blood stream by combining with haemoglobin in the blood, taking place of oxygen
What are the initial symptoms of carbon monoxide?
Slight headache
Fatigue
Mild discomfort in breathing
As carbon monoxide levels increase, what are the intermediate symptoms?
Impairment of vision
Mental confusion
Severe headache
Vomitting
What is the most common cause of carbon monoxide in the cockpit of a light aircraft?
Leaking exhaust (cabin heat)
If carbon monoxide is suspected, what should be done?
Cabin heat off
Fresh air vents opened
Use O2 if available
Land ASAP
What is the process of oxygenated blood and deoxygenated blood?
Oxygen delivered to brain and rest of body, deoxygenated blood returns to heart where it passes through system of valves, arteries and veins
What does heart do with deoxygenated blood?
Directs it to the lungs where it gives up its CO2 and collects fresh supply of O2
What is haemoglobin?
Iron rich pigment which is main component of red blood cell.
Carries oxygen
Does the brain monitor O2 or C02 levels in the body?
CO2 levels
What is the composition of atmosphere?
78% nitrogen
20% Oxygen
2 % other gases
What does transfer of oxygen into blood stream depend on?
Partial pressure within the lungs
What are the early symptoms of hypoxia?
NO feeling of suffocation
Mild intoxication
Marked reduction in night vision
What are the later symptoms of hypoxia?
Slowed thinking
Impaired judgement
Feeling of euphoria
Cyanosis (blue lips and fingernails)
At 20000 feet, what is the useful time of consciousness for person undertaking moderate activity?
10 mins
At 20000 feet, what is the useful time of consciousness for person sitting quietly activity?
20 mins
At 25000 feet, what is the useful time of consciousness for person undertaking moderate activity?
3 mins
At 30000 feet, what is the useful time of consciousness for person undertaking moderate activity?
1 min
At 25000 feet, what is the useful time of consciousness for person sitting quietly activity?
5 mins
At 30000 feet, what is the useful time of consciousness for person sitting quietly activity?
3 mins
For a normal person, what height does night vision degradation occur>
4000 feet
What are the symptoms of hyperventilation?
Similar to hypoxia
Light headedness
Tingling of arms and hands
What can help hyperventilation?
Holding breath
Voluntarily decreasing rate of breathing
Breathing into paper bag
Supplemental oxygen should be provided and used by the pilot at all times above what height?
10000ft
Above which altitude does it first become necessary for the pilot of an unpressurised aircraft to breath pure 100% oxygen?
33700 ft
Above which altitude does it first become necessary for the pilot of an unpressurised aircraft to breath pure 100% oxygen under pressure?
40000 ft
A regular smoker at sea level can be assumed to be at an effective altitude of?
8000ft
What does the sensory memory do?
Info from visual, audio, vestibular and proprioceptive sources is first directed here to be sorted
What happens to info in the sensory memory?
Some triggers reflex
Some passed to short term memory
Some is discarded
How long is visual info held for in the sensory memory?
0.5-1s
How long is auditory info held for in the sensory memory?
4-8 seconds
How long does short term memory hold info for?
7 items for about 30s
How long does long term memory last
1 min to a lifetime
What is episodic memory?
Contains past events that occur with their outcomes
What is semantic memory?
Assigning meaning to symbols, codes or words such as logos or flags
What is motor skills memory?
Complex individual tasks which have been linked through training and practice and become skills. Once learnt, little conscious effort is required
What is required in the decision making process?
Sensory memory
Short term memory
Long term memory
What can our attention be?
Selective or divided
What is selective attention?
Attention is focussed on those input data which are specific to particular task at hand to exclusion of irrelevant data
What is divided attention?
Requires us to perform separate tasks simultaneously
What sort of pilot is preferable?
P+G+ (person directed, goal directed)
How is information processed?
Sensation
Perception
Decision
Response
What is attitude?
Predisposition to response in certain way to particular person or situation
What can attitude incorporate?
Belief (cognitive)
Feeling (affective)
Action (behavioural)
What is the average retention span of the short term memory?
15-30s
The duration for sensroy memory for sounds is?
4-8s
What is the main function of semantic memory?
Recognise visual symbols, codes or logos
What is the main function of episodic memory?
Remember episodes of cause and effect that have occurred in the past
Cool headed self assurance would be an example of what?
Stable introvert
Which stage does motor program have difficut with?
Initiation
How is a person best able to recall info from short term memory?
Audible and clustered
What are the physical indicators of stress?
High pulse Dry mouth Sweating Hot flushes Sleeplessness/bad dreams Ulcers Head aches
What are the three stages for dealing with stress?
Alarm
Resistance
Collapse
What are coping strategies for stress?
Action coping
Cognitive coping
Symptom directed coping
What is action coping?
Taking action such as removing source of stress or removing yourself from stressful situation
What is cognitive coping?
Mind over matter.
Rationalisation along with intellectual or emotional detachment from situation
Councelling
What is symptom directed coping?
Seeking professional help/prescription drugs/recreational drugs
Which category of stress coping strategies does meditation and exercise fall under?
Symptom directed coping
What areas in your life should be investigated when dealing with stress?
Behaviour
Attitude
Fitness
How long is the circadian rhythms?
24 hours and 11 mins +/- 16 mins (approx 25 hours)
What happens to body rhythms when travelling east?
Body rhythms must advance
What happens to body rhythms when travelling west?
Body rhythms must retard
After a non stop flight through a 90 degrees change in longitude, the time required for the body rhythms to fully readjust to destinations local time would be?
4 days
What is the average rate at which the body resyncs’ to local time after travelling through a large change in longitude?
1.5 hours per day
Tasks are more likely to be affected by fatigue as the become more or less monotonous and complicated?
More monotonous
More complicated
What is the order for the decision making process?
Consider the facts Define problem Consider solution Act Consider result
What is the typical length of time a pilot will maintain vigilance?
30 mins
What is the error cause removal approach?
Encourage pilots to ID potential sources of error to prevent problems in the future
What is chronic fatigue likley to be cause by?
Long period of poor health
When conducting a procedural approach, a pilot uses what sort of behaviour?
Rule based
A pilot sitting 1 inch below DEP will lose how much forward visibility?
Approx 40m
What standard does DEP ensure?
Distance equal to 3s at approach speed is visible beyond cut off point and within 1200m visibility circle
What are linear strip displays ideal for?
Monitoring the performance of several similar systems (i.e. engines)
What are threats?
Originate in the environment outside the aircraft or in the cockpit that are not directly attributable to something the crew did/did not do
Promotes opportunity for pilot error
What are some examples of threats/
Poor weather
Wind shear
High pilot work load
What are errors?
Pilot actions or inactions that have potential to adversely affect safety of flight
What is undesired aircraft state?
Flight condition or attitude not intended by operating crew
What are some examples of undesired aircraft state?
Inappropriate flap
Flight above/below desired altitude
Airspeed too high/low
Unintentional spins/stalls
What are some examples of external threats
Distractions by passengers/crew Weather Heavy traffic Unfamiliar aerodrome Pressure to meet schedule Unexpected request/query from ATC Maintenance issues Missed approach Inflight diversion System failure
What can external threats be divided down to?
Anticipated
Unexpected
Latent
What is examples of anticipated external threats
Weather
Heavy traffic
Unfamiliar aerodrome
What are examples of unexpected external threats?
Distractions from passenger/crew
Inflight diversion
Missed approaches
What are examples of latent external threats?
Poor cockpit design/layout
Company policies
Optic illusions
What are examples of internal threats?
Pilot fatigue Language/cultural issues Pilot experience/personality Team familiarity Health/fitness Pilot recency/proficiency
What are examples of environmental threats?
Weather
Airspace communication problems
Ground environments (signage, birds, obstructions
Terrain
Operational pressures such as late arrivals or unservicabilities
What are examples of organisational threats?
Documentation errors
Tour of duty problems
A pilot under pressure form his employer to get back to base before his duty expires is what sort of threat?
Latent
What are the types of errors?
Handling
Procedural
Communication
When are handling errors likely to occur?
Pilot has limited total aero experience
What are some examples of handling errors?
Rounding too high/too late Failure to maintain track/heading Failure to maintain height Excess speed during taxi Harsh braking Poor crosswind technique
What are some examples of procedural errors?
Failure to use written checklist
Failure to fly RHC when required by ERSA
Failure to stop at holding point
Failure to conform to track/heigh limitations during instrument approach
Incorrect flight planning or weight and balance
What are some examples of communication errors?
Use of non standard terminology
Poor quality reception
Over transmission by third party
Unfamiliar accents or rapid speech
What is systematic error?
Definite pattern
All other elements of task are error free but error occurs regular in one particular element
What is random error?
No specific pattern.
Error occurs at different stage each time
What is sporadic error?
All elements of task performed satisfactorily most of the time.
Occasionally a serious error is made in one element
What are systemic countermeasures?
Built into the aircraft system to prevent threats and errors
What are some examples of systemic countermeasures?
Stall warning device
GPWS
Vacuum pump failure warnings
What are some planning countermeasures?
Preflight brief
WHat are some examples of execution countermeasures?
Monitoring systems in flight
Cross checking instruments
Workload/systems management
What are some examples of review countermeasures?
Monitoring progress of flight
A pilot who fails to apply carby heat during a glide has committed what?
Handling error
After being distracted by a difficult radio you deviate from your assigned level in CTA. What counter measure should you have taken?
Execution countermeasure requiring you to manage the workload
A pilot who resorts to assertiveness to address a problem is doing what?
Review countermeasure
Pilot planns to cruise at 5500 but given clearance to climb to 4500 in CTA but because of poor reception reads back 5500. What is this
Communication error
A pilot who is running late misses a NOTAM, and flies into it. What counter measure could have prevented this?
Planning countermeasure
What countermeasure would cross checking instruments fall under?
Execution countermeasure
What are the three types of undesired aircraft states?
Aircraft handling states
Ground navigation states
Aircraft configuration states
What are some examples of aircraft handling states?
Aircraft control (deviation in pitch, roll/yaw)
Altitude, track or speed deviations
Placing A/c in hazardous situation (weather or violation of CTA or CTAF)
Exceeding structural load factor/speed limits
Poor technique in flying the approach
What are examples of ground nav states?
Attempting to use wrong taxi way/runway
Taxiing too fast
What are examples of aircraft config states?
Inapproporate flap or speed brake selections Incorrect autopilot mode Incorrect GPS/nav aid programming Incorrect fuel distribution Incorrect weight distribution
What would regularly practicing forced landings be with regards to countermeasures and TEM?
Systemic countermeasure employed to manage an unexpected threat
What are the three levels of situational awareness?
Perception
Comprehension
Projection
