Human Factors Flashcards
What is the comfortable operating range for humans?
21-27 degrees Celsius
50% humidity
What is the formula for BMI?
Weight (kg) divided by height (m) squared
Under what conditions can heat stress occur?
Excess of 32 degrees Celsius
Excess exposure to sun
Under what conditions can hypothermia occur?
Exposure to less that 10 degrees Celsius
How long should you wait to fly after donating blood?
24 hours
A smoker physiological altitude is approximately what at sea level?
4000 ft
The inner ear is connected to the nasal cavity via what?
The euthaschian tube
Blocking of the euthaschian tube can lead to?
Otic barotrauma and pressure vertigo
What causes otic barotrauma?
Difference in pressure on either side of the ear drum
What can be done to relieve otic barotrauma?
Valsava technique
When is sinus barotrauma most likely to occur?
During descent
What causes air sickness?
Ambiguous signals arriving at the brain.
When sight, vestibular (inner ear) and or proprioception (skeletal and joints) signals conflict
What can assist with aiding airsickness?
Focusing on the horizon
Fresh air
Occupying mind with other things
Describe the 3 classes of medically and how long they are valid for.
Class 1 - CPL valid for one year
Class 2 - PPL valid for 4 years if under 40, 2 years if over 40
Class 3 - ATC valid for 2 years
CAR 256 states what about alcohol?
Pilot must not fly if consumption of drugs or alcohol impairs his/her capacity to act as PIC
Pilot must not consume alcohol within 8 hours of departure of aircraft
A pilot must not consume alcohol during flight
What diseases are directly associated with obesity?
Osteoarthritis
Hypertension (high blood pressure)
Gout
At what approximate height will a healthy human start to suffer effects associated with lack of oxygen?
14000 ft
At what height does it become necessary to break 100% oxygen or pressure cabin to approx 8000ft?
40000 ft
What are the symptoms of hypoxia?
Impaired judgement
Nausea and headache, frequent yawning
Tingling cyanosis (blue)
Personality changes (euphoria or aggression)
Poor muscular control and lack or coordination
Poor concentration
Vision, touch and hearing deteriorates
List the time available for useful consciousness at 20000, 25000 and 30000 feet
Altitude Moderate activity Sitting quietly
20000 10 mins 20 mins
25000 3 mins 5 mins
30000 1 min 3 mins
In the eye, what is responsible for night vision?
Rods, extremely sensitive to oxygen
What are the causes of hyperventilation?
Anxiety Motion sickness Vibration Heat High g forces
What are the symptoms of hyperventilation?
Lightheaded/dizziness Tingling, numbness and or stiffening of fingers, hands, toes and lips Anxiety Chest pains Reduced performance Collapse and unconsciousness
Carbon monoxide causes what?
Light headache
Fatigue
Mild discomfort in breathing
Unconsciousness and death
How is carbon monoxide likely to enter the cabin?
If there is a leak in the exhaust pipes, carbon monoxide can enter cabin via heater system
If carbon monoxide is detected, what actions should be taken?
Turn off cabin heat
Fresh air vents opened
Use oxygen if available
Land ASAP and investigate
What are the effects of negative acceleration on the body?
Fullness and pressure in the head Congestion of head and neck Eyelids swell Nose bleeds Red eyes and blurry vision
When can grey out occur and what are the symptoms?
3.5-4.5 g’s
Tunnel vision
What are the causes and symptoms of decompression sickness?
Nitrogen solution comes out of blood in the form of bubbles.
Sore joints, itching, dry cough, partial loss of vision
When can a pilot fly after diving?
Dive not requiring decompression stops - 4 hours
Dive less than 4 hours requiring decompression stops - 12 hours
Dive longer than 4 hours requiring decompression stops - 48 hours
Rods and cones sense incoming light and send signals to where?
The optic nerve
What do cones do in the eye?
Centrally located and specialise in colour perception and fine detail.
Requires bright light
The rods do what in the eye?
Function best in low light and chiefly responsible for night vision
What is rhodopsin?
Substance used to prime the rods for night vision
Takes approx 30-45 mins to develop
Can be destroyed with bright flash of light
What actions can assist night vision?
Avoiding bright lights Scan slower Look off centre Lower instrument lights Close one eye Wear sunnies during the day
What are threats?
Events or errors that: - occur outside the influence of the crew
-increase the operational complexity of the flight
-require crew attention and management if safety margins are to be maintained
E.g. Weather, other traffic, runway length, density altitude, high terrain, condition of aircraft
What are errors?
Lead to deviation from crew or organisational intentions or expectations
Reduce safety margins
Increase probability of adverse operational events on ground and in flight
(Handling, procedural or communication)
What are the priorities of survival?
Protection
Location
Water
Food
