SHELL MODEL
Model of human factors considering strengths and weaknesses
S = Software
H = Hardware
E = Environment
L = Liveware (you)
L = Liveware (others)
Nervous System Composition
Central = Brain & Spine
Autonomic = Automatic control e.g heart beat
Sensory-Somatic = Under voluntary control e.g muscle use
Autonomic & Sensory = Peripheral Nervous System
Blood Journey in Heart
Right Atrium -> Right Ventricle -> Left Atrium -> Left Ventricle
Blood Pressure
Measure of pressure exerted by blood on arterie walls.
High point = When heart contracts, Systolic.
Low point = Between beats, Diastolic.
Hypertension
Condition of consistently high blood pressure
Heart Disease
Blocking of heart arteries by fatty build up causing a clot and lack of sufficient oxygen to the heart.
Nervous Systems Roll in Circulation
AUTONOMIC nervous system monitors:
Need for blood to certain areas of body
Amount of CO2 in the blood.
Hypoxia
Lack of sufficient oxygen to body tissues.
Usually occurs at 10,000ft+
Hypoxia Symptoms
- Euphoria
- Clumsiness
- Drowsiness
- Headache
- etc.
Time of Useful Consciousness
Time available for pilots to perform usual tasks before severe hypoxia sets in.
(Gets shorter with altitude)
Hypoxic vs Anaemic Hypoxia
Hypoxic = Caused by lack of oxygen taken into the body.
Anaemic = Inability to of blood to carry oxygen e.g CO poisoning.
Hyperventilation
‘Over-breathing’ due to psychological distress e.g fear/anxiety.
How long to wait to fly after Scuba Diving?
12 hours where compressed air used to breathe.
24 hours when below 30ft for long periods.
Barotrauma
Gases getting trapped in the body e.g stomach and expanding as a result of increasing cabin pressure.
Rods
Used in peripheral vision, can’t see colour.
Cones
At the centre and used in regular vision, can detect colour.
Visual Acuity
Ability of the eye to see clearly and sharply.
Time to adapt to full darkness
30-40 minutes
Time to Impact on Direct Heading Courses
1nm of distance = 6 seconds
Where is the best focus point at night
20 degrees to the side
