Air Conditioning

Question 1

How many air conditioning zones are there?

Answer 1

3

Question 2

What is an ACSC and how many are installed?

Answer 2

Air Conditioning System Controller.

2 installed

Question 3

What is controlled by the respective ACSC?

Answer 3

ACSC 1: Cockpit zone and pack 1

ACSC 2: 2 cabin zones and pack 2

Question 4

What are the main components of the Pack?

Answer 4

Primary heat exchanger
Main heat exchanger
Air Cycle Machine

Question 5

How are the heat exchangers in the packs cooled?

Answer 5

Ram air

Question 6

How is temperature of the pack regulated?

Answer 6

Pack bypass valve modulates temp by adding hot air tapped upstream of compressor to the ACM turbine exhaust. Also regulated by modulating the ram air inlet flap.

Question 7

When is the pack flow control valve automatically closed?

Answer 7

• Low bleed pressure
• Pack overheat
• Engine start
• Engine fire pushbutton
• Ditching pushbutton

Question 8

What are the possible inputs to the mixer units?

Answer 8

• Conditioned air from packs
• Recirculated cabin air from the cabin fans
• LP ground connection conditioned air
• Emergency ram air

Question 9

How can the Hot Air PRV be controlled from the cockpit?

Answer 9

Using the HOT AIR pushbutton.

Question 10

How is the Hot Air PRV controlled?

Answer 10

By ACSC 1

Question 11

When will the Hot Air PRV close?

Answer 11

• Duct overheat
• Cockpit trim air valve fails
• Both cabin trim air valves fail

Question 12

When is the Ram Air flap closed?

Answer 12

• When T/O power is set

- On landing when struts are compressed >70kts (opens after 20 seconds)

Question 13

Which output temperature is produced by the packs?

Answer 13

Both pack will produce the lowest of the demanded temperatures.

Question 14

When will the packs revert to high flow regardless of switch position?

Answer 14

• APU supplying the packs

- Single pack operations

Question 15

What happens in case of a seized ACM compressor or turbine?

Answer 15

Pack reverts to heat exchanger mode.

• Uses primary heat exchanger only
• Reduced pack flow

Question 16

When does the pack flow control valve open again following engine start?

Answer 16

After 30 seconds provided:

• Start valve closed
• N2 > 50%

Question 17

What is the significance of a Pack FAULT light?

Answer 17

• Pack flow control valve disagree
• Compressor outlet overheat
• Pack outlet overheat

Question 18

Pressing the RAM AIR pushbutton, when will the ram air inlet open?

Answer 18

Opens if:

• Ditching pushbutton OFF
• Cabin pressure diff <1psi

Question 19

What cabin altitude will trigger EXCESS CABIN ALT ECAM?

Answer 19

> 9550’

Question 20

When will the safety valves open?

Answer 20

> 8,6 psi

< 1 psi

Question 21

How many motors drive the outflow valve?

Answer 21

3

Question 22

How many Cabin Pressure Controllers are there?

Answer 22

2

Question 23

What causes automatic changeover of CPC?

Answer 23

• Failure

- 70 sec after each landing

Question 24

What happens when pressing the Ditching pushbutton?

Answer 24

Provided to pressurisation mode is AUTO:

• Outflow valve closes
• Avionics inlet/outlet valves close
• Emergency ram air inlet closes
• Pack flow control valve closes

Question 25

What happens to the pressurisation on T/O?

Answer 25

Pre-Pressurisation when T/L set for T/O:

- Cabin climbs at 400’/min to 0,1 psi

Question 26

When is the outflow valve opened and any residual pressure released?

Answer 26

55 seconds after landing

Question 27

What is the max cabin altitude and pressure during cruise?

Answer 27

Approximately 8000’ and 8,06psi

Question 28

Can the CPC be manually changed?

Answer 28

Yes. By selecting manual for 10 sec, then re-select auto.

Question 29

When are the batteries ventilated?

Answer 29

Only in flight

Question 30

How are the lavatories and galleys ventilated?

Answer 30

By an electric fan exhausting the air overboard

Question 31

When do the avionics ventilation fans run?

Answer 31

Continuously when power is available

Question 32

When would the Avionics Equipment Ventilation be in the open circuit mode?

Answer 32

On the ground with skin temp above threshold ( >9-12°C )

Question 33

When would the Avionics Equipment Ventilation be in the closed circuit mode?

Answer 33

• On the ground with skin temp below threshold (<9-12°C)
• T/L set for takeoff
• In flight with skin temp below threshold ( <32-35°C )

Question 34

What is the main difference between closed circuit and open circuit?

Answer 34

In closed circuit, the skin heat exchanger is used.

- Inlet and exhaust valves are closed

Question 35

What happens when pressing OVRD in case of blower FAULT?

Answer 35

• Closed circuit configuration
• Blower stops
• Air conditioning inlet valve opens

Question 36

How is smoke configuration set on the Avionics Equipment Ventilation system?

Answer 36

Pressing OVRD on both blower and extract fan pushbuttons

Question 37

What happens in smoke configuration?

Answer 37

• Air conditioning inlet valve opens
• Blower fan stops
• All other valves close
• Air exhausted overboard through small flap in exhaust valve.

Question 38

Which two pack temperatures are displayed on the ECAM bleed page?

Answer 38

Compressor outlet (lower) and Pack outlet (upper)

Question 39

Is there any change in operation with the failure of one lane on one ACSC?

Answer 39

No effect

Question 40

If both lanes fail on one ACSC, can the other ACSC take control of the affected pack?

Answer 40

No. Pack is lost.

Question 41

At what cabin altitude will the signs automatically illuminate?

Answer 41

11.300’

Question 42

What is the cabin pressure limit? (Max and min)

Answer 42

+ 9.0psi

- 1.0psi