Human factors Flashcards
Symptoms of hyperventilation
Light headed ness Dizziness Tingling Visual disturbances Tremors Confusion Faintness Numbness
Symptoms of hypoxia
Euphoria Visual disturbances Light headed ness Dizziness Confusion Apprehension Sense of well being
Symptoms of CO poisoning
Headache Breathlessness Impaired judgement Feeling of warmth Sluggish Cherry red skin
Define time of useful consciousness
The time available for pilots to perform useful tasks without supplemental oxygen, before hypoxia sets in
Time of useful consciousness at 18000ft
20 mins at moderate activity
30 mins at minimal activity
What is the cornea
Transparent cap over the eye
What is lens
Changes shape to focus light
What is presbyopia
Lack of flexibility in lens with age, causing less curvature and therefore inability to focus
What is the retina
A light sensitive layer on back of the eye, made up of cones on the foveal region and rods outside the foveal region
What are cones
Sensitive to colour, details and distant objects
Most effective in good faith light
What are rods
Concentrated outside foveal region
Effective in day and night
Peripheral vision
Sensitive to movement but no colour or detail
What is blind spot
Small area on the retina where nerve fibres on the retina lead to the optic nerve
What is empty field myopia
Natural tendency when not trying to focus for eyes to focus only 1-2 metres away.
What is astigmatism
Curvature of cornea or lens not perfectly round causing uneven refraction
How long do eyes take to adjust to darkness
Cones 7mins
Rods 30mins
Best scanning technique
Scan whole field of view but in short increments. At night scan more slowly.
What is autokinesis
Visual illusion from staring continuously at a single bright object on a dark background. The more you stare the more it may oscillate.
What can cause false horizons
Sloping layers of cloud
Angled lines on ground
What can cause visual illusions on approach
Runway slope
Runway size
Haze
Parts of the inner ear
Cochlea - converts mechanical energy from ossicles into electrical energy
Vestibular Apparatus - 3 semi-circular canals that sense angular acceleration
Otolithic Organ - detects linear (fore, aft, up, down) acceleration
Parts of Middle ear
Ossicles - 3 small bones that take eardrum vibrations and magnify
Eustachian Tube - equalises middle ear pressure via nasal passage
What is presbycusis
Natural hearing loss with age especially in higher frequencies
What is false vertical
Otolithic organ detects direction of g forces but not origin, so in a balanced turn false vertical recognised
What is the leans
Perception of turn in other direction when
- gentle roll in not felt
- stop roll made briskly and felt as if initial roll in other direction