Air System

Question 1

The pneumatic air system supplies high pressure air for the following:

Answer 1

• Air conditioning
• Engine starting
• Wing anti-icing
• Water pressurization
• HYD reservoir pressurization

Question 2

Can the apu bleed air be used for wing anti-icing?

Answer 2

Yes but If wing anti-ice is used, APU BLEED ON is prohibited

Question 3

From what engine stage is bleed air normally drawn?

Answer 3

Air is normally bled from the intermediate pressure stage (IP) of engine’s high-pressure (HP) compressor to minimize fuel penalty.

Question 4

What will cause the hot air pressure regulating valve to close automatically?

Answer 4

The FAULT light comes on amber, along with an associated ECAM caution, when duct overheat is detected. The fault circuit detects an overheat when the duct temperature reaches 88 °C (190 °F) once. The valve and trim air valves close automatically. The FAULT light goes off when the temperature drops below 70 °C (158 °F), and the flight crew selects OFF.
The valve closes automatically, if:

‐ The duct overheats, or
‐ The cockpit trim air valve fails, or
‐ Both cabin trim air valves fail.

The hot-air pressure-regulating valve remains operative, even if either the forward or aft cabin trim air valve fails.

Question 5

How many channels are in the zone controller? What are they?

Answer 5

Two Channels. Primary and secondary channel.

PRIMARY CHANNEL FAILURE The secondary channel operates as backup. The flow setting function and optimized temperature regulation are not available.

Adittional:

HOT AIR and TRIM AIR valves close.
The zones are controlled to 24 °C (76 °F) (backup regulation).
Pack 1 controls the cockpit temperature.
Pack 2 controls the FWD and AFT cabin temperatures.

ALTN MODE appears on the ECAM (Electronic Centralized Aircraft Monitoring) COND page.

SECONDARY CHANNEL FAILURE This has no effect on zone temperature regulation. Backup mode is lost.

PRIMARY AND SECONDARY CHANNEL FAILURE
Optimized and backup temperature regulation is lost.
The packs deliver a fixed temperature: 20 °C (68 °F) for pack 1, 10 °C (50 °F) for pack 2.
The failure removes all information from the ECAM COND page, which then displays PACK REG.

Each controller consists of a primary channel that is normally in control and a secondary channel that acts as a backup if the primary channel fails.