Review Questions - Air Systems

Question 1

Which valves will receive a close command when the DITCHING pushbutton is depressed?

Answer 1

ARPO

Avionics Inlet and Extract valves

Ram air inlet

Pack Flow Control valves

Outflow valve (only if in AUTO mode)

Question 2

Will the DITCHING pushbutton always close the outflow valve?

Answer 2

Not if the outflow valve is under manual control

Question 3

Can the pilot control the outflow valve?

Answer 3

Yes, select MAN on the MODE SEL and use the MAN V/S CTL switch

Question 4

How many controllers are in the pressurization system?

Answer 4

2 - only one is used at a time and they swap roles after each landing

Question 5

How do you manually switch controllers?

Answer 5

Switch MODE SEL to MAN for 10 seconds, then back to AUTO

Question 6

What does an amber FAULT light in the MODE SEL pushbutton indicate?

Answer 6

Both automatic pressure controllers are faulty

Question 7

From what source does the pressurization system obtain landing elevation?

Answer 7

FMGC database

Question 8

When the mode selector is out of the AUTO position, how do you set a landing elevation?

Answer 8

Manually by selecting landing elevation via the LDG ELEV dial

Question 9

What protects the airframe from excessive cabin differential pressure?

Answer 9

2 pressure relief valves (safety valves)

Question 10

How many outflow valve motors are installed?

Answer 10

3 - One for each CPC and one for manual control

Question 11

What happens to the pack flow rate when APU bleed air is in use or during single pack operation?

Answer 11

Automatically goes to HI

Question 12

When should the PACK FLOW selector not be in the normal position?

Answer 12

a. Select LO: A319/A320 less than 115 and A321 less than 140 customers
b. Select HI: Hot and humid conditions
c. During Smoke/Fumes removal, select HI as per the procedure

Question 13

If the engine bleed air in-flight is too low what will occur?

Answer 13

Engine speed is automatically increased to provide adequate bleed air pressure

Question 14

What would cause an amber FAULT light to illuminate in the PACK 1 and/ or Pack 2 pushbutton

Answer 14

OOD

Overheat - Pack outlet

Overheat - Compressor outlet

Discontinuity - Switch position disagreement with pack flow control valve

Note: FAULT light will be illuminated when no bleed air is supplied.

Question 15

At what cabin differential pressure does the RAM AIR valve open?

Answer 15

1 PSI ΔP or less

Question 16

What causes the Pack Flow Control valve to automatically close?

Answer 16

UPEED

Upstream pressure below minimum

Pack overheat

Engine start sequence

Engine FIRE push button on the related side pressed

DITCHING push button is selected

Question 17

What does an amber FAULT light in the HOT AIR pushbutton indicate?

Answer 17

Duct overheat - the Hot Air and Trim Air valves close automatically

Question 18

How many Air Conditioning System Controllers are there?

Answer 18

2 - Each Air Conditioning System Controller has 2 lanes -(Active/Standby)

Question 19

Describe how the Air Conditioning System Controllers regulate temperature?

Answer 19

a. Basic temperature regulation: Both packs produce the required outlet temperature determined by the lowest demanded zone temperature.
b. Optimized temperature regulation: Hot air is added to the individual zones by the trim air valves to maintain the desired zone temperatures.

Question 20

What occurs when an active lane of an Air Conditioning System Controller fails?

Answer 20

The second lane takes over

Question 21

What occurs when both lanes of an Air Conditioning System Controller fail?

Answer 21

The related pack is lost. The hot air pressure regulating valve and associated trim air valve(s) close.

Question 22

How does the Air Conditioning System Controller configure its associated pack ram air inlet flap for takeoff and landing to avoid the ingestion of foreign matter?

Answer 22

Takeoff: Pack Ram Air Inlet Flap closes when takeoff power is set and the main landing gear struts are compressed. Reopens after main landing gear strut extension.

Landing: Pack Ram Air Inlet Flap closes as soon as the main landing gear struts are compressed and speed ≥ 70 knots. Opens 20 seconds after speed < 70 knots.

Question 23

If an air cycle machine (ACM) fails, what occurs?

Answer 23

The affected pack will operate as a heat exchanger

Question 24

What effect will the engine start sequence have on the pack flow control valves?

Answer 24

The pack flow control valve will close automatically

Question 25

What logic controls the X-Bleed valve when the X-BLEED switch is in AUTO?

Answer 25

a. When APU bleed valve is OPEN, the X-Bleed valve is open
b. When APU bleed valve is CLOSED, the X-Bleed valve is closed
c. X-Bleed also CLOSES for wing, pylon, or APU duct leak (except during engine start)