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A320 Notes > Pressurization > Flashcards

Flashcards in Pressurization Deck (51):
2

When does the  delta P indication become amber?

It becomes amber  when out of normal range  delta P 8.5 psi.

3

What is the function of the DITCHING pushbutton?

The DITCHING pb closes the outflow valve the emergency ram air inlet the avionics ventilation inlet and extract valves and the pack flow control valves.

4

How many motors are available to operate the outflow valve?

There are two automatic motors and one manual motor.

5

Pressurization is assumed through the following modes...

Ground (GN)
Takeoff (TO)
Climb (CL)
Cruise (CR)
Decent (DE)
Abort (AB).

6

How does the cabin pressure control work?

Two identical independent digital controllers automatically control the system by maintaining the proper cabin pressure. They receive signals from the Air Data Inertial Reference System (ADIRS) the Flight Management and Guidance Computer (FMGC) the Engine Interface Unit (EIU) and the Landing Gear Control Unit (LGCIU).

7

What are the main components of the pressurization system?

Two cabin pressure controllers (CPC) one residual pressure controller (RPCU) one outflow valve one control panel and two safety valves.

8

How many safety valves are installed?

Two independent pneumatic safety valves prevent cabin pressure from going too high (+8.6psi above ambient) or too low (-1psi below ambient).

9

Can you switch between the two cabin pressure controller (CPC)?

Switching the MODE SEL pb to MAN for at least 10 seconds then returning it to AUTO will select the other system.

10

Where is the outflow valve?

The outflow valve is on the right hand side of the fuselage behind the aft cargo compartment and below the flowtation line.

11

When does the cabin vertical speed (V/S) indication of the cabin pressure become amber?

It becomes amber  when the V/S is greater than 2000ft/min or less than -2000ft/min

12

What is the purpose of the Residual Pressure Control Unit (RPCU)?

The RPCU automatically depressurizes the aircraft in case of abnormal residual pressure on the ground.

13

What is the function of the abort mode?

If the aircraft does not climb after takeoff  the abort mode prevents the cabin altitude from climbing. Cabin pressure is set back to the takeoff altitude + 0.1psi.

14

When does the color of the cabin altitude indication on the ECAM change to red?

The indication becomes red for excessive cabin altitude >= 9550ft.

15

When does the safety valve open?

The safety valve opens when the cabin differential pressure is between 8.2 and 8.9 psi. The range is due to the reduced accuracy of delta P measurements (in MAN mode) combined with the decrease in cabin differential pressure that occurs immediately after the safety valves open.

16

What are the four general functions of the cabin pressurization system?

Ground function
Pre-pressurization
Pressurization during flight
De-pressurization

17

LDG ELEV selector
(CABIN PRESS Panel)


- AUTO
- Other position

AUTO:
FMGS data used to construct an optimized pressure schedule.


Other position:
The pressurization schedule does not use the landing elevation from the FMGS, but instead uses the landing elevation selected with this knob (from – 2,000 to + 14,000 feet) as its reference.

18

MODE SEL pb
(CABIN PRESS Panel)

- AUTO
- MAN
- FAULT Light

AUTO:
Automatic mode is operating. One of the two cabin pressure controller moves the outflow valve. Recycling this pb (MAN 10 sec then back to AUTO) switches controllers.

MAN:
MAN V/S CTL switch to control the outflow valve.

FAULT Light:
With ECAM caution light comes on only when both automatic systems are faulty.

19

MAN V/S CTL toggle sw
(CABIN PRESS Panel)

- UP
- DN

Springloaded to neutral. Controls the outflow valve position through operation of the MAN motor, when the MODE SEL pushbutton is in the MAN position.

UP: The valve moves towards the open position.

DN: The valve moves towards the closed position

20

DITCHING guarded pb
(CABIN PRESS Panel)

- ON

ON:
sends a “close” signal to:
- fwd cargo isolation outlet valve
The cargo recirculation fans stop automatically.
- avionics ventilation inlet and extract valves
- emergency ram air inlet
- pack flow control valves
- outflow valve

21

BLOWER and EXTRACT pb
(VENTILATION Panel)

- AUTO
- OVRD
- FAULT Light

AUTO (Both pb):
Open/closed config depending on temperature until TO power, then closed or intermediate.

(Either pb in OVRD):
- Closed config. A/C system supplies cooling.
- With BLOWER pb in OVRD blower fan stops.

(Both pb in OVRD):
- Air flows from the a/c sys and then overboard
- The extract fan continues to run.

FAULT Light (blower pb):
- blowing pressure low
- duct overheats
- computer power supply fails
- smoke warning is activated

FAULT Light (blower pb):
- extract pressure is low
- computer power supply fails
- smoke warning is activated.

22

FWD ISOL VALVE pb
(CARGO HEAT Panel)

- Auto
- OFF
- FAULT Light

Auto:
- The inlet and outlet isolation valves open.
- The extraction fan runs when the aircraft is on ground, or if diff P 1 psi, the fan stops.
- If smoke is detected in the forward cargo bay, the valves close and the fan stops.

OFF : The inlet and outlet isolation valves and the trim air valve close; the extraction fan stops.

FAULT lt:
With the ECAM caution when either inlet or outlet valve is not in the selected position.

23

Temperature selector
(CARGO HEAT Panel)

- COLD
- Middle position
- HOT

- COLD: Approximately 5° C (41° F)
- Middle position: Approximately 15° C (59° F)
- HOT: Approximately 26° C (79° F)

24

Zone temperature selector sw:
(AIR COND Panel)

- COLD
- Middle
- HOT

- COLD position: 18°C (64°F)
- Middle position: 24°C (76°F)
- HOT position: 30°C (86°F)

25

HOT AIR pb
(AIR COND Panel)

- ON
- OFF
- FAULT light

ON:
Hot Air Pressure Regulator Valve regulates hot air pressure.

OFF:
Valve closes, and the trim air valves close. The FAULT circuit is reset.

FAULT light on:
duct overheat temp = 88°C (190°F).
Triggers ECAM msg.
The valve and the trim air valves close automatically.
The FAULT light goes off when temp < 70°C (158°F), and the flight crew selects OFF.

26

PACK pb
(AIR COND Panel)

- ON
- OFF
- FAULT Light

ON:
Pack flow control valve is automatically controlled.
It opens, except:
- Upstream pressure below minimum;
- Compressor outlet overheat;
- Engine start sequence;
- Fire pb on same side is pressed;
- Ditching pb ON;

OFF:
The pack flow control valve closes.

FAULT LT:
Comes with ECAM
- valve position disagree with selected position
- compressor outlet overheat
- pack outlet overheat

27

ECON FLOW pb (321)
(AIR COND Panel)

- ON
- OFF

ON:
ECON flow is selected.

OFF:
Normal flow is selected. Normal flow provides 20 % more than ECON flow.

28

PACK FLOW sel (319)
(AIR COND Panel)

- LO
- NORM
- HI

LO (80 %)
NORM (100 %)
HI (120 %)

Goes into high when automatically when:
- single pack operation
- with APU bleed supply

If LO is selected, the pack flow can be automatically selected up to 100 % when the cooling demand cannot be satisfied.

29

RAM AIR pb (guarded)
(AIR COND Panel)

- ON
- OFF

ON:
- The RAM air inlet opens if the DITCHING pb is not selected ON.
- If differential press => 1 psi: The outflow valve control remains normal. No emergency RAM air flows in.
- If diff press < 1 psi: The outflow valve opens to about 50 % when under automatic control. It does not automatically open when it is under manual control. Emergency RAM airflow is directly supplied to the mixer unit.

OFF:
The RAM air inlet closes.

30

CAB FAN pb
(VENTILATION Panel)

- ON
- OFF

ON:
The two cabin fans are on.

OFF:
The two cabin fans are off.

31

CREW SUPPLY pb
(OXYGEN Panel)

- On
- OFF

On:
The valve is open, and supplies low pressure oxygen to the masks (normal position in flight).

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

32

PASSENGER SYS ON Iight
(OXYGEN Panel)

This light comes on white, when the control for the oxygen mask doors is activated, and it remains on until the TMR RESET pb is pressed.

33

MASK MAN ON pb
(OXYGEN Panel)

- AUTO
- Pressed

AUTO:
The mask doors open automatically when the cabin altitude exceeds 14,000 feet.

Pressed:
The mask doors open.

34

From what source does the pressurization system obtain landing elevation?

FMGC database

35

How many controllers are in the pressurization system?

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

36

When out of the AUTO position, what is different?

The pressurization system uses the manually selected landing elevation

37

When out of the AUTO position, what is different?

The pressurization system uses the manually selected landing elevation

38

When out of the AUTO position, what is different?

The pressurization system uses the manually selected landing elevation

39

What is the maximum cabin rate of descent with the pressurization in AUTO?

750 FPM

40

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

1 psi differential or less

41

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

- Avionics Inlet and Extract valves

- Ram air Inlet

- Pack Flow Control valves

- Outflow valve (only if in Auto mode)

42

Will the DITCHING pushbutton always close the outflow valve?

Not if the outflow valve is under manual control

43

Can the pilot control the outflow valve

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

44

Will the DITCHING pushbutton always close the outflow valve?

Not if the outflow valve is under manual control

45

What protects the air frame from excessive cabin differential pressure?

2 pressure relief valves

46

How many outflow valve motors are installed?

3 - One for each automatic controller and one for manual control

47

If PACK FLOW is selected to HI, will it automatically shift lower?

No

48

How do you manually switch controllers?

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

49

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

Both automatic pressure controllers are faulty

50

Describe what occurs when cabin pressure altitude exceeds:

- 8,800'
- 9,550'
- 11,300'
- 14,000'

- 8,800': CAB ALT flashes

- 9,550': EXCESS CABIN ALT warning

- 11,300': All cabin signs illuminate

- 14,000': All passenger masks deploy

51

If the Lav/Galley Extract Fan fails, what occurs?

Cabin temperature defaults to a set value

52

Approximately what rate of cabin change does 1 click of the MAN V/S CTL switch produce?

50 FPM