ECS

Question 1

What must be controlled to maintain various aspects of the cabin environment? (5)

Answer 1

Temperature
Humidity
Ventilation
Purity
Pressure

Question 2

Atmospheric pressure …… with increasing altitude

Answer 2

decreases

Question 3

Temperature of air decreases by approximately how many degrees per 1000 ft and until what ft does the temperature remain at -56.5 degrees?

Answer 3

2 degrees
36000 ft

Question 4

What are the dry volumetric proportions of the gases in the atmosphere?

Answer 4

78% Nitrogen
21% Oxygen
1% other gases

Question 5

At 26,000ft what is the temperature?

Answer 5

-36 degrees

Question 6

Sea level Temperature, Pressure and density?

Answer 6

Temperature - 15 degrees C
Pressure - 1.0132 bar or 14.7 PSI
Density - 1.225 kg/m3

Question 7

Other pneumatic sources include? (6)

Answer 7

Ram air
Fan
Compressors
APU
Air bottles
Ground Supply

Question 8

Cabin conditioning used to? (4)

Answer 8

Provide heating, ventilation and humidity control
Provide emergency ventilation
Automatic control of cabin pressures at different altitudes
Provide ancillary services

Question 9

Air conditioning provides? (2)

Answer 9

Aircrew comfort - improves safety and efficiency
Radar and equipment cooling

Question 10

Cabin Pressurisation defined as?

Answer 10

Controlled pressure created within an aircraft cabin in excess of ambient atmosphere, to stimulate lower altitude

Question 11

Why are military aircraft limited to cabin differential air pressure? (2)

Answer 11

Heavier structure
Explosive decompression

Question 12

Hot air is tapped from where and goes to?

Answer 12

Engine compressor and goes to the pressure reducing and shut off valve

Question 13

What happens when the pressure reducing and shut off valve is open?

Answer 13

airflow flows to the heat exchanger and cold air unit, and also to the temperature control valve

Question 14

What controls the temperature of the air that is fed to cabin conditioning and how is the air fed into the cabin?

Answer 14

Temperature control valve
fed into cabin via a water extractor

Question 15

What controls the leakage in and out of the cabin to provide for ventilation and pressurisation?

Answer 15

Pressure controller and discharge valve

Question 16

What does the pressure reducing and shut off valve do?

Answer 16

Automatically governs the mass air flow into the system by varying the outlet according to the compressor output pressure, ensuring a constant flow rate

Question 17

What 2 compartments does a heat exchanger have?

Answer 17

primary (pre cooler)
secondary (inter cooler)

Question 18

What does the oil pack of a cold air unit consist of?

Answer 18

Absorbent material impregnated with oil
Felt Wicks lead from the absorbent material to the bearings
Depression caused by the rotation of the scroll pumps draw oil up the felt wicks and pumps deposit oil to the bearings

Question 19

What is the function of the water extractor?

Answer 19

Removes most of the water from the airflow before it passes from the conditioning supply system

Question 20

What happens if the coalescer becomes blocked in the water extractor?

Answer 20

relief valves opens due to increased pressure adnd allows air to pass through the swirl plates and collector tubes

Question 21

Up to what ft is the cabin pressure the same at atmospheric pressure?

Answer 21

8,000 ft

Question 22

At 25, 000ft what is the maximum pressure that is achieved and maintained to the aircraft cieling?

Answer 22

4psi

Question 23

What is the purpose of the pressure control and discharge valve?

Answer 23

To control the pressure of the air within the aircraft cabin by control the flow of air out the cabin