ATA 21 - Air Conditioning / Pressurization / Ventilation

Question 1

In case of zone controller primary and secondary channel failure, what temperatures are maintained by pack one and pack two?

Answer 1

20°C pack1 and 10°C pack 2

Question 2

Pack controller, primary and secondary channel failure consequences ?

Answer 2

Pack outlet temperature is controlled to between 5 and 30 deg C by the anti-ice valve

Question 3

Bleed air supplied from the APU (APU bleed valve open), which pack flow is automatically selected ?

Answer 3

High

Question 4

When does normal cabin air pressurization occur?

Answer 4

During take off roll

Question 5

When does normal depressurization is completed ?

Answer 5

1 min after landing

Question 6

Max altitude for Ram Air ?

Answer 6

10 000ft

Question 7

Cabin pressure limitation with ram air utilisation ? Outflow valve position ?

Answer 7

Cabin differential pressure 1psi max. Outflow valve open at 50% if in auto mode.

Question 8

General description of Air conditioning system ?

Answer 8

Cf diagram

Question 9

Temperature corresponding to temperature selector COLD, NORM, HOT ?

Answer 9

18, 24, 30 °C

Question 10

Description of a Pack ?

Answer 10

Cf diagram

Question 11

Pack controller closes valve when :

Answer 11

• IGN / START ( closed until 2nd engine start or 30s)
• ENG FIRE PB
• DITCHING PB
• no air / overheat / overpressure

Question 12

When pack air intake and outlet valves close ?

Answer 12

At take off
At landing (until < 70 kt + 20s)

Question 13

Pack controller primary channel failure consequences ?

Answer 13

Works on secondary channel
Not optimized, previous flow is frozen

Question 14

Description of avionic ventilation system ?

Answer 14

Cf diagram

Question 15

How many cabin pressure controller are they ?

Answer 15

2, cycle every landings

Question 16

Maximum cabin rate of descent ?

Answer 16

750 ft /min

Question 17

Excess cabin altitude alarm at which altitude ?

Answer 17

9550 ft

Question 18

No smoke, seat belt, Exit lights automatically ON at which cabin altitude ?

Answer 18

11300ft

Question 19

Number of safety valves and max cabin pressure value ?

Answer 19

2 safety valves, 8,6psi

Question 20

CPC 1 has a back up independent power supply. True / False ?

Answer 20

True

Question 21

The lavatory/galley extract fan operates:
a.
Continuously when electrical power is available
b.
Only on the ground
c.
Only in flight

Answer 21

A

Question 22

If bleed air is being supplied by the APU or if one pack fails; pack flow will go to what rate?

Answer 22

High

Question 23

How many motors are available for the outflow valve?

Answer 23

3 motors

Question 24

When either the BLOWER or EXTRACT switches are in OVRD; air from the air conditioning system is added to ventilation air. True or False ?

Answer 24

True

Question 25

What is the number of occupants below which you select Pack flow LO ? A318,A319, A320,A321

Answer 25

A321: 168 (ECON)
A320: 141
A319: 138
A318: -

Question 26

Following an ECAM CAB PRESS SYST 1 AMBER FAULT. SYSTEM 2 takes over automatically without crew action. True or False ?

Answer 26

True

Question 27

During landing run PACK AIR FLAPS open when speed is less than XX kts ?

Answer 27

70kts + 20s

Question 28

The cabin zone temperature sensors are ventilated by the air extracted by the lavatory and galleys extraction fans. True or False ?

Answer 28

True

Question 29

The outflow valve is powered by how much electric motors ?

Answer 29

3
2 for auto control
1 for manual control

Question 30

Consequence of a ACSC (Air Conditioning System Controllers) total failure ?

Answer 30

Pack lost