AIR CONDITIONING & PRESSURIZATION

Question 1

RAM AIR pb

Answer 1

• selecting ON opens the inlet if the differential pressure is less than 1 psi
• for smoke removal
• for cabin ventilation in the case of a dual PACK failure

Question 2

HOT AIR pb

Answer 2

• selected ON (lights out), the valve regulates hot air pressure
• selected OFF, the valve closes and the trim air valves close

Question 3

HOT AIR FAULT

Answer 3

• duct overheat
• hot air and trim valves close automatically
• PACK 1 controls the cockpit to last selected value
• PACK 2 controls the cabin to the average selected by the FWD and AFT cabin temperature selector knobs

Question 4

PACK FAULT

Answer 4

• valve position disagreement
• compressor outlet overheat
• PACK outlet overheat

Question 5

PACK flow : LO / ECON

Answer 5

A320 less than 141

A321 less than 168

Question 6

How can a pilot manually switch pressure controllers?

Answer 6

select MAN for 10 seconds then back to AUTO

Question 7

When will the EXIT signs illuminate?

Answer 7

cabin altitude in excess of 11,300

Question 8

MODE SEL pb FAULT

Answer 8

• both automatic pressure controllers are faulty

Question 9

DITCHING pb

Answer 9

The ditching pb closes…

• the outflow valve
• the RAM AIR inlet
• the avionics vent inlet and outlet valves
• the PACK flow control valves
• the FWD cargo isolation outlet valve
• all valves below the water line

…and stops the cargo recirculation fans

Question 10

How is the landing field elevation entered into the pressurization system?

Answer 10

• Automatic via the FMGC (LDG ELEV must be in AUTO)
• Semi-Automatic via the LDG ELEV selector button
• Manual via the MODE SEL in MAN and then using the
  MAN V/S CTL toggle

Question 11

When is the ditching pb used?

Answer 11

ditching

& de-icing

Question 12

How many controllers are there in the pressurization system?

Answer 12

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

Question 13

What protects the airframe from excessive cabin differential pressure?

Answer 13

Two pressure relief valves
+8.6 psi

Question 14

What does selecting the ditching pb ON accomplish?

Answer 14

It closes all openings below the water line, but if both pressurization controllers have failed you must manually close the outflow valve.

Question 15

X-BLEED rotary selector

Answer 15

SHUT = the valve is closed
OPEN = the valve is open
AUTO = open if the APU bleed valve is open,
closed if the APU valve is closed or wing pylon
or APU leak (except during an engine start)