Threats To Aviation

Question 1

Hypoxia

Answer 1

Insidious Hypoxia = major threat to flight crew

Ensure supply of oxygen above 10,000ft
Passengers bring
Stop smoking
Only fly when fit

Question 2

Decompression Sickness Cause

Answer 2

Ambient temp reduces at altitude
Bubbles merge to become larger bubble (Air embolism)
Become trapped in joints and block normal passage of blood
Tissue downstream of blockage deprive of o2 and dies

Question 3

When is decompression sickness likely

Answer 3

18,000-25,000ft unlikely below 14,000ft

Question 4

Factors of DCS

Answer 4

High alt
Duration of exposure
Age
Excess body weight
Scuba diving

Question 5

Symptoms of DCS

Answer 5

Bends - Bubbles in joints NO1 symptom

Creeps - bubbles under skin

Chokes - Bubbles in capillaries and lungs

Staggers - bubbles in brain

Question 6

DCS Treatment

Answer 6

Descend (Nitrogen to dissolve back into solution)
100% oxygen
Urgent medical assistance on landing

Question 7

Scuba Diving on DCS

Answer 7

Compressed air - descent increases partial pressure of nitrogen so saturation of nitrogen increases in tissue

Takes time to excrete excess nitrogen
Risk of flying even at cabin alt of 6000ft

(PREVENTED BY BREATHING 100% OXYGEN)

Question 8

Scuba Diving rules and flying

Answer 8

Do not fly 12 hours after diving or use of compressed air

Avoid flying 24 hours if depth of 30ft exceeded

Question 9

Acceleration durations

Answer 9

Long = 1+ sec (+3.5G relaxed/7 to 8g using anti straining techniques)
(-3G but only short periods)

Short = less than 1 sec
(+25G in vertical axis)
(+45G in fore/aft axis

Question 10

Gx

Answer 10

Linear (fore and aft)
Forward acceleration

Question 11

Gz

Answer 11

Vertical acceleration
Heavier
More blood to feet than brain
Hydrostatic variation increases

Question 12

Gx

Answer 12

Linear - sensory illusion in pitch axis
Somaticgravic illusion

Large forward acceleration makes you feel as though pitching up
Large rearward acceleration makes you feel as though pitching down

Question 13

Vertical Gz effect on body

Answer 13

Increase in body weight so harder to move (2g above mobility impaired)

Increase in hydrostatic variation of the blood pressure

Question 14

+G force stages

Answer 14

Grey OUT (3/4G) - Rod and cones need disproportionate amount of oxygen causing tunnel vision

Black out - (5G above) lose consciousness

Question 15

Negative -G effects

Answer 15

Organs force upwards/blood forced to head (decreased hydrostatic variation)

Respiration difficulties/facial pain/red out/lower eyelid pushed up/slower hear rate

Question 16

Barotrauma

Answer 16

Injury caused by pressure differential

Question 17

Otic Barotrauma

Answer 17

Ear
Worse in descent when air attempting to return to middle ear
Eustachian tube one way valve

Question 18

Sinus Barotrauma

Answer 18

Sinus — inside facial bones around nose blocked by mucus and infection

If you experience this stop descent return to previous altitude and slowly descend again
In climb stop climb and land asap

Question 19

Aerodontalgia Barotrauma

Answer 19

Gas pockets in old or poor fillings
Commons in the ascent as gas expands
Not occur in descent

Question 20

Gastro-Intestinal Barotrauma

Answer 20

Gas expanding in small intestine

Question 21

Humidity in cabin

Answer 21

5-10% (Prevent corrosion to airframe and electrics)

Question 22

Incapacitation

Answer 22

Gastro main cause

UNCLEAN FOOD OR WATER

Question 23

High Altitude flying millisieverts limits

Answer 23

Max 20 mSv a year

Question 24

Alcohol Effect

Answer 24

1 unit per hour (15mgs/100ml per hour)
Rate of elimination slows down during sleep

Question 25

Bends

Answer 25

Bubbles in joins Descending can reduce symptoms Most common symptom of DCS

Question 26

Creeps

Answer 26

Nitrogen bubbles under the skin

Question 27

Chokes

Answer 27

Nitrogen bubbles in capillaries of the lungs

Question 28

Staggers

Answer 28

Nitrogen bubbles in blood supply to brain and nervous system

Question 29

Uphill terrain

Answer 29

Uphill slope = appearance of being too high

Question 30

Downhill Slope

Answer 30

Illusion of being too low

Question 31

Alcoholism symptoms

Answer 31

Higher tolerance to alcohol Withdrawal symptoms Conflict with the law

Question 32

Alcohol Consumption

Answer 32

No alcohol should be consumed less than 8 hours prior to reporting time for flight duty Blood levels should not exceed 0.02% at start of flight duty and duty period

Question 33

Average amount of cosmic radiation flight crew receive per year

Answer 33

Equal to amount of background radiation Average around 4.0 mSv per year MAX IS 20mSv

Question 34

Which combination of factors associated with alcoholism

Answer 34

Genetics Access to cheap alcohol Social cultural background

Question 35

Reversion

Answer 35

Usually in emergency under pressure - automatically doing what you used to as under pressure

Question 36

What is a fume event

Answer 36

Abnormal odours, smoke, haze or fumes in the cabin Toxic environment created by contaminated bleed air Can include: - fire extinguisher discharge in cockpit - eye irritation - carry on baggage - cleaning products - food items