Human Factors Flashcards
Class 1 Medical
Validity: 1 year or 6 months when over 65
To exercise the privileges of CPL and ATPL
Full Class 2 Medical
Valid: 4 years below 40 or 2 years when 40 and above
For the privileges of an RPL and PPL and, if non-passenger carrying, CPL (MTOW < 8616kg)/flight instructing
Basic Class 2
GP Issuable
PPML: Private Pilot Medical License
For MTOW < 8618kg, day VFR, < 10,000ft AMSL, max 5 paxs, piston engine, no operational ratings, no flight activity endorsements
Valid: 5 years under 40
: 2 years over 40
: 1 year over 70Class 3 Medical
ATC
Valid: 2 years
RAMPC Medical
Valid: 2 years under 65 years or GP dependent
: 12 months 65 and over
For single engine piston aircraft, MTOW < 1500kg, day VFR, < 10,000ft AMSL, no aeros and only 1 pax
Heart Disease and Angina
Angina: a symptom of an underlying heart problem (eg. coronary heart disease)
Reduces blood supply to the heart due to blocked arteries, placing stress on the heart, leading to pain
Causes include: smoking, high cholesterol, obesity and alcohol
Atmospheric Makeup
Nitrogen 78%
Oxygen 21%
Carbon Dioxide 0.03%
Which remain constant with altitude
ISA Temperature and Pressure
Temperature: Drops 1.98 deg per increase of 1000 feet in altitude
Pressure: Drops 1 hpa per increase of 30 feet in altitude
Upper Respiratory Tract Infections (URTI’s)
Very common, usually airborne in nature
Results in pain and pressure of the ear due to middle ear infections
Symptoms of Upper Respiratory Tract Infections
Reddening of the eyes
Blockages of airways
Headaches
Examples of Upper Respiratory Tract Infections
Cold Flu Hayfever Congestion Sinus Infections
Daltons Law of Partial Pressure
Total pressure exerted by a volume of gas is equal to the partial pressures of the individual gasses
Pressure Required by the Human Body
Requires at least 55mmHg or 74hpa of pressure to breathe naturally, approx 10,000ft
Average pressure = 1013.25 hpa, pressure exerted by oxygen = 21% = 212hpa
Hypoxia
A condition in which the body is deprived of oxygen
Types of Hypoxia
- Hypoxic: Oxygen reduced (eg. high altitudes, as low as 4000 ft AMSL)
- Anaemic: Carrying capacity reduced (eg. low red blood cells, CO poisoning)
- Stagnant: Circulation reduced (eg. poor circulation)
- Histotoxic: Interference of the use of oxygen (eg. alcohol)
Signs and Symptoms of Hypoxia
Vision impairment Cyanosis Mental confusion and poor judgement Poor motor coordination Hyperventilation Feeling of euphoria Apprehension Nausea and headaches Dizziness Hot and cold flushes Numbness and tingling Unconsciousness Death
Causes of Hypoxia
Smoking Drinking Extreme temperatures Physically unfit Increased demand for oxygen
Food Poisoning
Gastroenteritis
#1 cause of pilot incapacitation
Caused by bacteria, viruses and other pathogens
Symptoms of Food Poisoning
Nausea Stomach cramps Vomiting and diarrhoea Fever Headaches
Headaches and Migraines
Non-specific pain symptoms (many causes)
Neurological disorder characterised by repeated attacks of severe and debilitating headaches
Generally between 4 hours and 3 days
Symptoms of Headaches and Migraines
Throbbing and pulsating to one side of the head
Nausea
Sensitivity to bright lights and noise
Pregnancy
CASA allows 30 weeks and 6 weeks after
Problems arise from ergonomics and mood swings
Physical Injuries
Can interfere with pilots capacity
Ageing
Reduces response time, increases likelihood of medical complications, deteriorations in sensory info
RPT pilot retirement: 65 years of age
PIC over 60 must have a younger co-pilot
Blood Donations
Side effects: within 10-15 mins, cause dehydration
DAME advice, with 24hrs before flight operations
Dehydration
Deficiency of water
Symptoms: Headaches, dizziness, nausea, weakness and light headedness, delirium, swelling of the tongue, unconsciousness
Alcohol
Absorbed rapidly through the stomach and small intestine and is transported to the brain via blood
Can prevent the brain from making use of oxygen
Can remain for 72 hours
A central nervous system depressant
Effects of Alcohol
Impaired reaction time, judgement, thinking process and memory Blurred/double vision Dizziness Decreased hearing perception Slurred speech Impaired motor skills
Elimination of Alcohol
Excrete 2% - 8% and metabolise 92% - 98%
Average rate of elimination: 15mg/hr or 1.5 standard drinks per hour
Hangover
Nausea Headaches Vomiting Lethargy Upset sleep patterns Impaired judgement Dry mouth and thirst
Blood Alcohol Concentration
Amount of alcohol in a persons blood stream by measuring the difference between the absorption rate and elimination rate, plateaus 30 mins after last drink
Affected by body size, food intake, body fat, gender and amount of alcohol consumed
Law on Alcohol Consumption
8 hours prior to scheduled time of departure cannot drink with a 0 BAC whilst on duty
A 0.02% buffer for perfume and mouthwash
Prescription Drugs
Prescribed by a doctor and should consult a DAME before consuming to ensure no side effects
Hyperventilation
The washout of carbon dioxide from your body
The body is ventilating carbon dioxide faster than it can produce it, voluntarily or involuntarily, characterised by over-breathing
Symptoms of Hyperventilation
Dizziness Weakness Lightheadedness Shortness of breath Tingling around the mouth and fingertips
Treatment for Hyperventilation
Remove person from the causes of stress
Paper bag method
Acceleration (G Forces)
A measurement of acceleration a body feels as an increase or decrease of ‘apparent weight’
Blood to the head: Negative G manoeuvres - redout (-2.0g)
Blood at the feet: Positive G manoeuvres - greyout (+3.5g)/balckout (+5.0g)/G-LOC (>+5.0g or +5.0g sustained)
Atmospheric Pressure Changes
Trapped gasses (dysbarism or barotrauma)
- Will cause a problem with atmospheric pressure changes
- If body cannot equalise pressure discomfort can occur
- Certain foods can increase the likelihood: onions, radishes, beans cabbage, etc
Application of Boyles Law to Diving
As a diver ascends the surrounding pressure decreases and the compressed nitrogen expands, if not completed slowly enough pain can be caused: decompression sickness
Symptoms of Decompression Sickness
Joint pain Muscle pain Numbness Tingling Red rash Respiratory problems Paralysis Death
CASA Guidelines for Diving
Dive with no decompression stops = 4 hours rest
Dive for less than 4 hours with decompression stops = 12 hours rest
Dive for > 4 hours with decompression stops = 48 hours rest
Toxic Hazards
Carbon monoxide poisoning: incomplete combustion of carbon compounds from the aircraft engine
An aircraft may have carbon monoxide detectors
Symptoms of Carbon Monoxide Poisoning
Headaches Dizziness Blurred vision Disorientation Nausea and vomiting Rapid heartbeat Loss of hearing Weakness Loss of consciousness Seizures Respiratory failure Cardiac arrest
Treatment for Carbon Monoxide Poisoning
Remove the source or person
Ensure fresh air
medical treatment
Information Processing
The 5 senses receive information and send it to the brain (the central processing unit of the body)
Works in this way:
1. Sensation: information received
2. Perception: what the brain thinks is happening
3. Response: how the brain is going to respond
4. Action: now the body acts
Limited by :
- The number of items the mind can hold
- The rate at which the mind can process and use the stimuli
Human Memory
Process in which information is stored, encoded and retrieved
Short Term Memory
2-5 seconds
Long Term Memory
Indefinite
Consists of:
- Semantic memory: memory of meaning, understanding and other concept based knowledge
- Episodic memory: memory of autobiographical events (times, places and associated emotions)
Stress
Natural human mechanism inbuilt for reasons of survival
Positive or negative condition impacting a persons mental and physical well-being
Short term = acute: Can increase performance
Long term = chronic: Occurs with a lack of recovery time between acute stress events
A persons ‘Fight or Flight Mechanism”
Types of Stressors
Environmental: from surrounding environment
Heat: excessive heat leading to dehydration
Cold: excessive cold
Vibration: shockwaves can damage body tissue
Domestic: home life
Work: workplace
Symptoms of Stress
Fatigue Memory problems Moodiness and irritability Withdrawn personality Alcohol and drug abuse Lack of sleep Kidney and liver problems
Stress Management
Relaxation therapy
Finding an outlet (exercise)
Medicine
Cognitive behavioural therapy
Fatigue
Subjective feeling of tiredness, categorised as acute or chronic in nature
Acute Fatigue
Tiredness within approx 24 hours
Chronic Fatigue
Prolonged fatigue which becomes debilitating
Fatigue Treatment
Rest
Diagnose
Medical attention
Medication
Ergonomics
Engineers incorporate ergonomic design features
Improve efficiency and safety for the human body and cognitive abilities
Reduce the risk of errors and confusion and prevent repetitive strain injuries (RSI)
The Ear
Responsible for hearing, balance and body position
Outer Ear
Pinna (auricle)
Ear canal
Ear drum
Middle Ear
Air filled cavity
Ossicles: Hammer, anvil and stirrup (3 bones), which amplify the vibrations
Eustachian tube: Connected to the upper throat, which equalises pressure between internal and external pressures, allowing air to escape more easily than entering
Inner Ear
Cochlea: Converts vibrations to nerve impulses via tiny hairs
Semi-circular canals
Otolith organs: Utrical and saccule
Auditory nerve
Split anatomically into bony and membranous labyrinths
Path Through the Ear
Pinna Ear canal Ear drum Ossicles Cochlea
Eustachian Tube
Descent: Increase in pressure, air wants to enter which can cause pain
Valsalva Manoeuvre
Equalise any pressure differentials, opens eustachian tube to allow air to enter
Hearing Loss
- Conductive: defect of bones (ossicles) or ear drum
- Sensorineural: failure of the auditory nerve
- Presbycusis: age induced
Decibel level above 85 deemed hazardous
140 decibel level will cause pain
The Eye
Binocular in its makeup
Responsible for sight, balance and body position
Path Through the Eye
Cornea
Lens (fine focus): Controlled by ciliary muscles which also controls the iris, altering the size of the pupil (giving light), in line with the fovea (central cones) and the retina (rods) for peripheral vision
Image is transferred to the brain by the optic nerve
Components of the Eye
Pupil: Allows light to enter onto the retina
Lens: 25% - fine focusing
Cornea: 75% - coarse focusing
Retina: Contains photo receptors
- Cones: Colour, shape, detail, bright light (fovea), don’t work well at night (create a blind spot), forms central vision, concentrated on fovea
- Rods: Forms peripheral vision, distinguish movement with no colour and little detail, work best in low levels of light, located on the outside edges of the retina
Light Adaptation
Approx 5 mins for eye to adapt to bright from dark
Approx 30 mins to adapt from dark to light
Empty Field Myopia (Short sightedness)
Eyes have nothing to focus on and lens relaxes, focusing automatically at a range of 1-2 metres ahead
Causes blurred vision without pilot knowledge
Detection of movement outside of the field of view can be delayed and hard to determine in nature and range
Glare
Reduction of pupil size, arising from bright light
Use a visor or sunglasses
Colour Vision
Pilots must have full colour vision due to coloured charts
Myopia
Short-sighted
Cornea is elongated in the horizontal plane
Light isn’t directly focused on the retina
Correction with a concave lens
Hypermetropia
Long-sighted Cornea elongated in the vertical plane Focus on things far away Image focuses behind the retina Corrected with a convex lens
Astigmatism
Cornea becomes uneven in its shape
Light focuses in front or behind the retina
Correction with a cylindrical lens
Presbyopia
Progressively diminished ability to focus on near objects with age
Lens hardens and ciliary muscles become weaker
Flicker Vertigo
Imbalance in brain-cell activity due to an exposure to a flickering light causing disorientation
Illusions and Disorientation
Enhanced by: bad weather, saccadic eye movement (eyes jiggle - less focus), haze, pollutants and sunlight
To prevent risks: fly with visual reference, avoid staring at lights, fatigue - allow eyes to adapt to lights
Equilibrium
Established and maintained in the human body with three sensory systems: visual, auditory and proprioceptive systems
Without Equilibrium
Can lead to disorientation
- The leans (body doesn’t recognise a slow turn)
- Linear and angular acceleration illusions (not knowing if you are pitching up or accelerating)
- Auto-kinetic illusions (where a stationary light appears to move as your eyeballs start to jiggle)
- Graveyard spin
Unperceived changes in the 3 axis of concentration
Motion Sickness
Disagreement between the bodies 3 systems of equilibrium
Recovery: Look at the horizon, loosen clothing, open air vents, use supplemental oxygen, avoid head movements
Landing Illusions
Wide: Closer
Narrow: Further away
Slope up: Approach angle too high
Slope down: Approach angle too low
Motion Parallax Illusions
Objects from a distance appear to move slowly
Objects viewed closer appear to move much faster
Body Rhythms: Circadian rhythm
Natural sleep/wake cycle of the body
Body Rhythms: Desynchronisation
Jet lag
Travelling east is harder (body clock must speed up)
Adjust by approx 1.5 hours per day
Body Rhythms: Human Efficiency
At its worst: early am and early afternoon (post-prandial dip)
Body Rhythms: Rapid Eye Movement (REM) & Sleep Pattern
Older: need less sleep, but less flexible when you sleep
A Threat
Anything that has the potential to negatively impact the safety of the flight
Types of Threats
Expected Unexpected Latent Internal External
Internal Threats
Flight crew only
Eg. Pilot proficiency, cultural differences, illness, fatigue, accents, conflicting personalities, etc
External Threats
Anything but the flight crew
Environmental
Organisational
Environmantal Threats
Anything around the aircraft
Eg. weather, CTA, CTAF, terrain, high traffic density, unfamiliar aerodrome, etc
Organisational Threats
From the organisation/company
Eg. Maintenance issues, differing procedures, student pilot guide different to what is taught, flight and duty problems, etc
An Error
Pilot action or inaction
Types Of Errors
Handling
Procedural
Communication
Handling Errors
Actual flying of the aircraft
Eg. Using too much power on final, not looking out, raising nose of the aircraft too high on round out, not sufficient hold off, etc
Procedural Errors
Failure to follow procedure
Eg. Failing to use checklists, weight and balance done incorrectly, doing left circuits when ERSA said right circuits, failure to stop at holding point, etc
Communication Errors
Misinterpreting communication
Eg. Non-standard format broadcast, not listening to whole ATIS, fast speech, bad radios, etc
Undesired Aircraft States
Anything the aircraft shouldn’t be doing or where it shouldn’t be
Types of Undesired Aircraft States
Aircraft Handling
Ground Navigation State
Incorrect Aircraft Configurations
Aircraft Handling
Anything to do with flight condition
Eg. Stall, spin, spiral dive, too high, low, slow or fast on final, exceeding VNE, violation of CTA or PRDs, not enough crosswind correction, etc
Ground Navigation State
Anywhere aircraft shouldn’t be whilst on the ground
Eg. Using wrong taxiway/holding point, taxiing too fast, run off the runway, etc
Incorrect Aircraft Configurations
Anything you can set
Eg. QNH setting, trim, flaps, DG misaligned, X-Pond, radio frequencies, auto pilot mode, power setting
Outcome
Either positive or negative
Types of Countermeasures
Planning
Execution
Review
Systemic
Planning Countermeasure
Anything that can be done prior to flight
Eg. Thorough pre-flight, checking weather and NOTAMs, plan B’s, etc
Execution Countermeasure
Making sure that all systems are running correctly
Eg. Cross-checking instruments, prioritising and managing tasks, checking ERSA, etc
Review Countermeasure
Tasks that require evaluation of the situation
Eg. Choosing to abort takeoff after seeing oil pressure not in the green, following general direction when lost, diversions, etc
Systemic Countermeasure
Anything built into the aircraft
Eg. Ammeter low volt light, stall warning, gear warning, circuit breakers, TCAS, etc
