Pressurization

Question 1

When does ∆P become amber ?

Answer 1

When out of normal range
≤ -0.4 or ≥ 8.5 PSI

Question 2

What is the function of DITCHING pb ?

(APROF)

Answer 2

Close all the valve below the floatation line:
* Avionic ventilation inlet and extract valve
* Pack Flow control valve
* emergency Ram air inlet
* Out flow valve
* FWD cargo outlet isolation valve

(APROF)

Question 3

How many motors available to operate outflow valve ?

Answer 3

Three electric motors
* 2 motors for automatic
* 1 motor for manual

Question 4

What are the main components of pressurization systems ?

Answer 4

• 2 Cabin pressurization controllers (CPC)
• 1 Residual pressure control unit (RPCU)
• 1 outflow valve
• 1 control panel
• 2 safety valve

Question 5

How many modes of pressurization are there when in automatic ?

Answer 5

6 modes:
* Ground (GN)
* Takeoff (TO)
* Climb (CL)
* Cruise (CR)
* Decent (DE)
* Abort (AB)

Question 6

What is Ground mode ?

Answer 6

Before T/O and landing 55s, outflow valve is fully open. At touch down the remaining cabin press is released at V/S = 500ft/min

Question 7

What is Takeoff mode ?

Answer 7

System will pre-pressurize the cabin with rate of 400ft/min until ∆P=0.1 PSI

Question 8

What is Climb mode ?

Answer 8

Cabin alt varies according to a fixed-programmed law that take into account a/c rate of climb

Question 9

What is Cruise mode ?

Answer 9

Controller maintain cabin alt at level off value of landing elevation, whichever higher, but the Max cabin alt is 8000ft

Question 10

What is **Descent **modes ?

Answer 10

Controller maintain cabin rate of descent, such that cabin press = landing field press +0.1 PSI, shortly before landing.
Max descent rate is 750ft/min

Question 11

What is Abort modes ?

Answer 11

If a/c does not climb after T/O, the abort mode prevent cabin alt from climb.
Cabin press is set back to +0.1 PSI

Question 12

What are the inputs of CPC ?

Cabin pressurization controllers

Answer 12

• Landing elevation and QNH from FMGC
• Pressure alt from ADIRS
• If FMGC data not avail, controller will use captain BARO from ADIRS and LDG ELEV selection
• Engine interface unit (EIU)
• LGCIU

Question 13

How many controller are there?

Answer 13

Two identical, independent, automatic systems (each consisting of a controller and its associated motors) control cabin press.

Question 14

Can two controller work at the same time ?

Answer 14

No, only one controller operates at a time

Question 15

When will Controller 2 take over ?

Answer 15

Automatic tranfer occurs:
* 70s after each landing
* If operating system fails

Question 16

RAM AIR pb is ON, ∆P<1PSI, but the outflow valve not open, Why ?

Answer 16

Because outflow valve is under manual control

Question 17

How does safety valve work ?

Answer 17

They are pneumatic operate, which prevent cabin press, ∆P > 8.6 or < -1 PSI

Question 18

What does RPCU do ?

Answer 18

It automatically depressurize the A/C in case of abnormal residual pressure on ground by open the outflow valve.

Question 19

During manual operation of pressure system, you increase the cabin alt by switching the toggle to UP position, but the outflow valve position on ECAM not moving, what should you do ?

Answer 19

Wait 5s as the operation of outflow valve in manual is slower and the resolution of outflow valve position on ECAM is limited.

Question 20

How to change btw two pressure controller system ?

Answer 20

Switch MODE SEL pb to MAN for at least 10s then switch back to AUTO

Question 21

What does FAULT light in MODE SEL pb indicate ?

Answer 21

Both automatic system are faulty

Question 22

DITCHING pb is ON, but outflow valve not closed, Why ?

Answer 22

Because MODE SEL is in MAN

Question 23

On PRESS page, cabin V/S is flashing, what does this mean ?

Answer 23

cabin V/S reach 1750ft/min
(stop flashing when return below 1650ft/min)

Question 24

On PRESS page, cabin alt is flashing, what does this mean ?

Answer 24

Cabin alt reach 8800 ft
(stop flashing when below 8600ft)

Question 25

When does cabin alt turn red ?

Answer 25

Cabin alt at or abv 9550 ft

Question 26

What does an amber “SAFETY” mean ?

Answer 26

either safety valve is open

Question 27

When does ouflow valve position indication become amber ?

Answer 27

when outflow valve open more than 95% during flight

Question 28

Where is the outflow valve ?

Answer 28

On the right hand side of fuselage, behide the aft cargo compartment, below the floatation line

Question 29

From what source does the pressurization obtain the landing elevation ?

Answer 29

If system is in AUTO then landing elev will be obtain from FMGS
If system is in Manual then landing elev will be obtain from LDG ELEV knob

Question 30

What is cabin max rate of descent with pressurization in AUTO ?

Answer 30

750ft/min

Question 31

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

Answer 31

∆P ≤ 1

Question 32

What protects the air frame from excessive cabin differential pressure ?

Answer 32

2 safety valve

Question 33

When will safety valve open ?

Answer 33

8.9psi < ∆P < 9.7psi

Question 34

Describe what occurs when cab alt exceeds:

- 8800ft
- 9550ft
- 11300ft
- 14000ft

Answer 34

• 8800ft: CAB ALT flash
• 9550ft: Excess CAB ALT warning
• 11300ft: All cabin signs illuminate
• 14000ft: All pass masks deploy

Question 35

MASK MAN ON pb

(OXYGEN panel)
* Auto
* Pressed

Answer 35

• Auto: the mask doors open automatically when cab alt exceeds 14000ft
• Pressed: the mask doors open

Question 36

PASSENGER SYS ON light

(OXYGEN panel)

Answer 36

This light come on white, when the control for oxygen mask door is activate, and remain on until TMR RESET pb is pressed.

Question 37

CREW SUPPLY pb

(OXYGEN panel)
* ON
* OFF

Answer 37

-ON: the valve is open, and suppies low press oxygen to the masks

-OFF: valve is closed, and the white light comes on