Human Performance Flashcards
SHELL model
S - software (manuals, procedures)
H - hardware (equipment)
E - environment
L - Liveware (other people)
L - Liveware (pilot)
Pilot liveware is central to the other 4.
2 components of liveware considerations
- Psychological
- Physiological
Nervous system components
Central - Brain & spinal cord
Peripheral - Networks of nerves and ganglia
Division of peripheral nervous system
Autonomic: Organs and non-voluntary functions such as heart beat, sweating, digestion.
Sensory-somatic: Everything under voluntary control
Cardiovascular system components
Heart
Blood vessels
Blood
Types of blood vessel
Arteries: Thick, carry blood from heart
Veins: Carry blood back to heart
Capillaries: Smaller vessels joining arteries to veins, travelling in networks through organs.
Two parts of blood circulation
Systemic circulation: From left side of heart, through organs, back to right side of heart.
Pulmonary circulation: From right side of heart, through lungs, to left side of heart.
Hypertension
High blood pressure
Can lead to heart attack. Caused by lifestyle factors.
Coronary Heart Disease
Fatty layer building up in coronary arteries.
Bits breaking off can form blood clots, blocking the coronary artery.
Caused in part by lifestyle factors.
Respiratory system functions
i) Gas exchange
ii) Immune defence (infection entering lungs)
iii) Talking
iv) Release of chemicals, proteins & enzymes
3 types of respiration
External (breathing)
Internal (exchange of gases in lungs or organs)
Cellular (oxygen being used by cells to create energy)
What does the body use to determine respiration rate?
CO2 levels
Time of useful consciousness at altitude
Moderate & minimal activity
22k feet: 5 mins & 10 mins
25k feet: 2 mins & 3 mins
30k feet: 45 secs & 75 secs
35k feet: 30 secs & 45 secs
40k feet: 12 secs & 15 secs
Altitude at which body reacts to decreasing pressure
7,000ft
Altitude at which atmospheric pressure is half MSL
18,000ft
2 types of hypoxia
Hypoxic hypoxia (insufficient oxygen coming into body)
Anaemic hypoxia (inability of blood to carry oxygen)
Initial symptoms of hypoxia
Euphoria, clumsiness, impaired judgement.
Hyperventilation
- Cause
- Misdiagnosis
- Treatment
Caused by excess carbon dioxide, body attempts to flush it out.
Can be confused with hypoxia which is more serious to treat, more likely explanation at unpressurised high altitude.
Treat by blowing into paper bag, slowing breathing.
Scuba-diving delays
12 hours down to 10m
24 hours beyond 10m
Barotrauma
Gases trapped in your body (e.g. stomach, inner ear, tooth cavity) expanding during descent.
6 main eye components
Cornea - transparent cap, solid shape
Iris - Coloured area in front of lens
Pupil - Gap in middle of iris allowing light through, changes size to control light.
Lens - Transparent, muscles control its shape to focus light
Retina - Back of the eye, covered in light sensitive cells
Optic nerve
2 types of retina cells
Cones: Foveal vision, concentrated in central area of retina, colour sensitive and best in daylight.
Rods: Peripheral vision, further from foveal region, not colour sensitive but work well in the dark and detect movement well.
Autokinesis
Illusion of movement when you stare at a static light in darkness.
How is false horizon illusion caused?
A sloping layer of cloud can be taken as a false horizon leading to adopting a non level attitude
Myopia
- Cause
- Correcting glass type
Short sightedness
Lens is too convex (can’t flatten enough) so light from far away is bent too much and focuses in front of the retina
Concave glass lens to correct
Hyperopia/Hypermetropia
- Cause
- Correcting glass type
Long sightedness
Lens is not convex enough so light from close up can’t be redirected enough to focus on retina (focus point behind retina)
Convex glass lens to correct
Presbyopia
Long sightedness that is common in 40s and beyond.
Presbycusis
Deterioration in hearing due to age
Astigmatism
Curvature of cornea or lens is not perfectly round leading to uneven refraction and distorted images.
Accomodation
The ability to focus on near and far objects
Time required to develop night vision (and adapt to bright light)
30 minutes (and 10 seconds)
Optical illusion caused by rain on windscreen
Makes objects appear lower than they are (so aircraft appear higher) leading to a low approach.
Strongest vision area for rods
10 degrees off centre
Likely effect of approach to brightly lit runway with no other lights near it?
Black hole effect.
Pilot is likely to descend early leading to a low approach
What distance do eyes tend to focus at in the dark with nothing to focus on
1-2 metres
Time before flying after cataract or corneal surgery
24 hours
3 components of outer ear
External ear: Pinna or Auricle, gathers sound signals
Outer canal: Pressure waves pass through
Eardrum: Vibrates in harmony with pressure waves
2 components of middle ear
Ossicles: 3 small bones, forced by eardrum, convert pressure wave energy to mechanical energy.
Eustachian tube: Connects middle ear to nasal passages to allow pressure to match ambient pressure
Barotitis
Air being trapped in the middle ear