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Introduction Information1. WELCOME : Primary purpose of attendance - Flight Safety.

Normal body in abnormal environment. Man – machine interface.

2. COFFEE and TEA : Crewroom. SR 2 per person / day.

NO food or drink in the classroom.

3. FIRE. Evacuate via front doors or as directed by Instructor.

4. TOILETS.

5. NO SMOKING.

6. MOBILE PHONES, switched OFF

7. COURSE LEADER.

8. START TIMES and PROGRAMME.

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Introduction Information11. CONDITIONS : Must be present for all lectures & chamber runs.

12. PRAYER TIME ARRANGEMENTS. Location of mosque.

14. CERTIFICATES.

15. EXAMINATION: Multiple choice, 4 possible answers (only one

correct).

Pass mark = 60%.

Failure - Re-sit different exam next day.- Recourse.

ANY QUESTIONS.

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Medical officers introduction to aviation medicine.

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Objectives

Describe the structure and layers of the atmosphere

Explain the change in physical properties with ascent to altitude

Define the Gas Laws applicable to the aviation environment

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Layers of the Atmosphere

Mt Everest 29,028 ft

EXOSPHERE

IONOSPHERE

STRATOSPHERE

TROPOSPHERE

TROPOPAUSE

30 MILES

435 MILES

1,200 MILES

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Functions of the Atmosphere

Radiation Protection UV and sub-atomic particles Ozone Layer (~ 40K`-140K`) 3 O2 + UV <=> 2 O3 + HEAT

Thermal Protection Cloud reflects IR radiation (Greenhouse) Pollutants cause excess....Global

Warming

Gaseous Support of Life O2 , CO2 , H2O

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The ICAO Standard AtmosphereWhere it is / at 45°N in North America.

Air = dry, dust-free, stated composition

Pressure (MSL) = 1013 Hpa

Density (MSL) = 1.225 kg/m3

gconstant = 9.80665m/s2

Temp/alt profile +15 0C at MSL Lapse rate = 1.98 0C/1000’ to 36 089’ (= tropopause) Isothermal layer temp = -56.5 0C Rises to -46 0C at 100,000’

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Composition of the AtmosphereOxygen

21%

Nitrogen

78%

Rare gases (eg. methane, ozone, CO2)

1%NB. Although pressure changes with altitude, this percentage relationship

remains constant

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Problems with Altitude

Pressure drops

Temperature drops (Lapse rate)

pO2

pN2

Gas expands

Sea Level

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Standard

Atmosphere

Chart

-62.2 -51.1 -40.0 -28.9 -17.8 -6.7 44 15.6

TEMPERATURE – DEGREES CENTIGRADE

-80 -60 -40 -20 200 40 60

TEMPERATURE – DEGREES FAHRENHEIT

100,000

90,000

80,000

70,000

60,000

50,000

40,000

30,000

20,000

10,000

Sea Level

HEIGHT feet

TROPOPAUSE - POLES

TROPOPAUSE - SA

TROPOPAUSE - EQUATOR

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Pressure Changes with Altitude

10,000 ft – 2/3

18,000 ft – 1/2

33,700 ft – 1/4

25,000 ft – 1/3

253.2 HPa

337.6 HPa

506.5 HPa

675.3 HPa

1013 HPa

0 10,000 20,000 30,000 40,000 50,000 60,000

Altitude (Feet).

100

200

300

400

500

600

700

800760

0

Pre

ssur

e m

m H

g

43,000 ft – 1/6

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TheTheGasGasLawsLawsBoyle :

Charles :

Henry :

Dalton :

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The Law of Gaseous Diffusion Henry’s Law

A gas will move from an area of higher pressure to an area of lower pressure.

Oxygenation within the body depends on this law.

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Partial Pressure Dalton’s Law

Air at Sea Level

O2 = 21%pO2 = 160mm Hg

N2 = 78%pN2 = 593mm Hg

Other = 1% = 7 mm Hg

Total = 100% = 760 mm Hg

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Gas Expansion With Altitude.

Boyle’s Law : P X V = K

10,000 ft – 2/3

18,000 ft – 1/2

33,700 ft – 1/4

25,000 ft – 1/3

100

200

300

400

500

600

700

800760

00 10,000 20,000 30,000 40,000 50,000 60,000

253.2 HPa

337.6 HPa

506.5 HPa

675.3 HPa

1013 HPa

Pres

sure

mm

Hg

Altitude (Feet).

43,000 ft – 1/6

Sea Level – 1/1

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Atmospheric pressure Atmospheric pressure

Atmospheric pressure

Eardrum

Opening to throatEustachian tube

Nerve to brainThe Middle Ear

Body Cavities Containing Gas (1)

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Atmospheric pressure

DECREASES

Pressure INCREASES

Air vents to throat

Climbing

Eustachian tube

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Atmospheric pressure

INCREASES

Pressure DECREASES

Air must enter via Eustachian tube.

Descending (Normal)

Eustachian tube

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Atmospheric pressure

INCREASES

DECREASED Pressure

BLOCKED.

Wall of Eustachian tube sucked in.

Eardrum sucked in.

PAIN !PAIN !PAIN !PAIN !PAIN !

Descending (Blocked)

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Body Cavities Containing Gas (2)

Middle Ear.

Sinuses.

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Frontal sinus

Maxillary sinus

Ethmoidal sinuses

Sphenoidal sinus

The Sinuses

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Maxillary

Ethmoid

Frontal

Location of Sinus Cavities

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Body Cavities Containing Gas (3)

Middle Ear.

Sinuses.

Lungs.

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Gas Expansion in the Lungs

Pneumothorax

Air embolism

Pneumomediastinum

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Body Cavities Containing Gas (4)

Middle Ear.

Sinuses.

Lungs.

Gastrointestinal Tract.

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Gas Expansion

Stomach

Large bowel

Small bowel??

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Body Cavities Containing Gas (5)

Middle Ear.

Sinuses.

Lungs.

Gastrointestinal Tract.

Post surgical

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Body Cavities Containing Gas (6)

Middle Ear.

Sinuses.

Lungs.

Gastrointestinal Tract.

Post surgical.

Post trauma.

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Body Cavities Containing Gas (7)

Middle Ear.

Sinuses.

Lungs.

Gastrointestinal Tract.

Post surgical.

Teeth.

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Teeth

Problems on Climb :

Bad fillings.

Abscess.

Dental hygiene is important.

Visit the Dentist every 6 months.

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Prevention of Trapped Gas Problems

Fly only when healthy

Do not self medicate

Equalise pressures frequently on descent

Avoid gas producing foods, before flying.

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Prevention of Trapped Gas Problems

Never fly with a cold or sore throat.

Do not self medicate.

See the Flight Surgeon if you are sick.

Equalise pressures frequently on descent.

Valsalva or roll the jaw.

Avoid gas-producing foods before flying.

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Total atmospheric pressure falls

pO2,

pN2,

Gas expands.

Hypoxia above 10,000 ft.

DCI above 18,000 ft.

Sinuses.

Sea level

Temperature falls

2°C / 1000 ft.

Physical Changes in the Atmosphere

Stomach.

Ears.

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Body Cavities Containing Gas (8) Middle Ear / External Ear.

Sinuses.

Lungs.

Pneumothorax.

Gastrointestinal Tract.

Hernia.

Bowel.

Post surgical.

Teeth.

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AEROMEDICAL CENTRE

K.A.A.B. DHAHRAN

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Remember

Pain anywhere in the body

DURING CLIMB

COMPLETE OBSTRUCTION.

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