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Flashcards in Aircon and Pressurisation Deck (15)
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1
Q

What are the two types of controlling cabin temperature?

A

Vapour Cycle

Air cycle Machine

2
Q

What does the vapour cycle do?

A

Process and uses the evaporation of refrigerant gas which causes temp to drop

3
Q

Where is vapour cycle commonly used?

A

Business jets

Light turboprops

4
Q

What does aircycle do?

A

Cooling air by expansions as it drives a turbine

5
Q

Where is air bled from for aircon?

A

Hot compressed air is bled from high pressure end of gas turbine engine compressor

6
Q

What is ram air from the ram air door used for in air con system

A

Cool primary and secondary heat exchangers. Results in less work by air cycle machine

7
Q

Where is the water separator located?

A

Between the trim air valve and cabin air valve

8
Q

What are the two types of pressurisation control?

A

Auto and Manual

9
Q

What happens when max differential is reached and aircraft still climbs?

A

Cabin climbs at same rate as aircraft

10
Q

What do outflow valves do?

A

Regulate outflow of cabin air to control cabin pressure at desirable and safe levels

11
Q

What sort of signals do outflow valves respond to?

A

Electrical or pneumatic

12
Q

How is the outflow valve opened and closed?

A

Spring loaded to closed

Low pressure vacuum pumps open it

13
Q

What happens if cabin pressure exceeds a certain predetemined value?

A

Outflow valve will open, cabin air flows overboard

14
Q

What are negative relief valves?

A

Cabin air pressure inside is greater than outside air pressure.
Spring loaded doors, valve that opens to dump excess pressure overboard

15
Q

When do negative relief valves open?

A

Negative pressure reaches 0.5psi