Pneumatic

Question 1

What is the high pressure air is used for ?

Answer 1

For air conditioning, pressurization, hydraulic tank pressurization, wing anti ice, water tank pressurization and engine start.

Question 2

From where the bleed air from the IP valve is bled from ?

Answer 2

From the 7th Intermediate Pressure (IP) stage from the engine High Pressure (HP) compressor section

Question 3

What is the purpose of the IP check valve ?

Answer 3

To prevent bleed air from circulating back to the 7th stage compressor.

Question 4

What happens if IP pressure is not sufficient ?

Answer 4

Engine bleed air is bled from the High Pressure valve

Question 5

What is the minimum required amount of bleed pressure before the HP valve opens ?

Answer 5

At least 8 PSI to open the HP valve

Question 6

From where the bleed air from the HP valve is bled from ?

Answer 6

From the 10th High Pressure (HP) stage

Question 7

What is the normal bleed pressure that the system maintains ?

Answer 7

It maintains at 36 PSI +/- 4 PSI

Question 8

What is the purpose of the bleed valve, aka pressure regulator vavle (PRV) ?

Answer 8

The valve acts as a shutoff valve and regulates pressure to 45 PSI +/- 5 PSI

Question 9

What is the possible fluctuation regarding the bleed air pressure during climb up to FL100 ?

Answer 9

It may fluctuate between 38 PSI and 56 PSI at high engine power during climb up to FL100

Question 10

What is the purpose of the overpressure valve ?

Answer 10

The valve protects the system from overpressure. It is fully automatic and can not be controlled by pilots.

Question 11

What is the maximum pressure to reach before the overpressure valve closes to reduce pressure ?

Answer 11

80 PSI (75 PSI on NEO)

Question 12

What is the purpose of the precooler ?

Answer 12

As the temperature of the bleed air is regulated by the precooler, it acts as a heat exchanger that uses cold fan air to maintain the temperature at 200°C

Question 13

How is the bleed air cooled down ?

Answer 13

By a fan air valve that draws air from the engine fan to the precooler. It closes if temp °C is below 200°C, or opens if temp °C is above 200°C

Question 14

What is the purpose of the crossbleed valve ?

Answer 14

It allows the air supply systems of the two engines to be interconnected or isolated

Question 15

How many motors does the crossbleed valve have ?

Answer 15

2 electric motors, one for AUTO mode and one for MANUAL mode

Question 16

How many loops do the wings have ?

Answer 16

Both wings have a dual loop (loop A and loop B)

Question 17

What happens when a leak is detected ?

Answer 17

If a leak is detected by both loops (or one loop with the other one inoperative), a wing leak signal is sent

Question 18

How many loops do the pylons and the APU have ?

Answer 18

a single loop

Question 19

How is the wing protected from overpressure ?

Answer 19

The wing is equipped with a blown down panel to protect the integrity of the leading edge bay against overpressure

Question 20

How many underwing blown down panels are there ?

Answer 20

5 underwing blown down panels :
- 3 inboard of the engine pylon
- 2 outboard of the engine pylon

Question 21

What is the minimum pressure required in the leading edge before an overpressure is triggered ?

Answer 21

When the pressure reached approx 7 PSI, the rivets of the panel shear and the trailing edge opens, venting the air overboard

Question 22

What happens during a BMC failure ?

Answer 22

The other BMC takes over control, but the associated FAULT light is not operative anymore and the associated bleed valve does not close automatically.

Question 23

What is the required upstream pressure to open the bleed air valve ?

Answer 23

above 8 PSI

Question 24

When does the precooler inlet pressure become amber on the ECAM page ?

Answer 24

If under 4 PSI, or if an overpressure is detected (threshold between 57 and 60 PSI)

Question 25

When does the precooler outlet temperature °C become amber on the ECAM page ?

Answer 25

If an over temperature (or low temperature) is detected :

• 290°C for more than 5 seconds, or
• 270°C for more than 15 seconds, or
• 257°C for more than 55 seconds

Question 26

When a low temperature situation can be detected ?

Answer 26

Only in-flight, if bleed temp °C is below 150 °C, with wing anti-ice ON and bleed air valve (PRV) open

Question 27

When does the ARROW (wing anti ice) on the ECAM page become amber ?

Answer 27

• Valve is open and air pressure is low or high, or
• Valve is open on the ground for more than 10 seconds