Stage 6 Pneumatic

Question 1

What does pneumatic system provide?

Answer 1

High pressure air for:

1) Air Conditioning
2) Engine Start
3) WAI
4) Water/HYD Reservoir pressurization
5) FTIS

Question 2

What are the bleed sources in the A/C?

Answer 2

1) Engines
2) APU load compressor
3) HP Ground connection

Question 3

What connects into the XBleed duct?

Answer 3

APU, ground and engines

Question 4

What computer controls the pneumatic system and relay its ECAM indications and warnings to pilots?

Answer 4

BMC 1 and 2 (Bleed Monitoring Computer)

Question 5

Where is the leak detection system located?

Answer 5

Detects overheating at the vicinity of hot air ducts

Question 6

How does BMC control engine bleed?

Answer 6

1) Selects the stage to bleed form

2) Regulates the bleed temperature and pressure

Question 7

What happens if one BMS fails?

Answer 7

The other takes over most functions. Only functions lost are leak detection of onside engine bleed and APU leak detection incase of BMC 1 fail

Question 8

How are bleed valves controlled and actuated in the pneumatic system?

Answer 8

They are electrically controlled by their associated BMC and pneumatically actuated

Question 9

When is HP stage used in engine bleed?

Answer 9

At low engine power IP might not be enough to maintain 36psi -/+4

Question 10

how is air from HP stage prevented from recirculating into the IP stage?

Answer 10

Via an intermediate pressure check valve

Question 11

When does the HP valve close automatically ?

Answer 11

Exessive or low upstream pressure

Question 12

When does the bleed valve close by pilot action?

Answer 12

by BLEED or ENG Fire pbs

Question 13

When does the bleed valve close automatically?

Answer 13

if BMC detects

1) Overpressure and Overtemperature
2) Leak
3) Open Starter Valve
4) Engine Shutdown
5) APU Bleed ON
6) No consumers

Question 14

If APU bleed is ON and Xbleed is Closed what happens to ENG 2 Bleed?

Answer 14

Remains open

Question 15

How is temperature regulated initially after the air is bled?

Answer 15

A precooler uses engine fan air to reduce bleed air down to 200C

Question 16

What does the APU Bleed pb do?

Answer 16

Open X Bleed if in AUTO and shuts off Engine Bleed

Question 17

When does APU bleed automatically close?

Answer 17

1) APU Leak

2) left wing or pylon 1 leak detected

Question 18

How is XBleed vavle controlled?

Answer 18

Knob in A/C panel controls two electric motors, one automatic and one manual

Question 19

What does Auto Xbleed do?

Answer 19

Xbleed opens when APU bleed is used and closed when a leak is detected/APU bleed off

Question 20

How is bleed leak detected?

Answer 20

Leak detection loops detect overheating near hot air ducts in fuselage, pylons and wings.

Question 21

How many leak detection loops are for the pylon, APU and wings?

Answer 21

1) APU and pylon have one loop

2) Wings have dual loops with a similar logic to fire detection

Question 22

What automatically happens when a wing or pylon leak is detected?

Answer 22

The BMC will:

1) Onside bleed valve closes and related FAULT light on
2) X-Bleed closes (Except engine start)
3) APU valve closes if left wing leak

Question 23

What does a APU leak cause?

Answer 23

1) APU bleed valve closes and related FAULT light on
2) X-Bleed valve closes (except engine start)
Note: Only BMC 1 is connected to APU loop

Question 24

When does the ENG Bleed turn on the OVHD panel ir pressed?

Answer 24

1) Sufficient pressure
2) APU Bleed is Off/Closed
3) No onside leak
4) ENG Fire pb in
5) Engine start valve closed

Question 25

What causes a FAULT to appear on ENG bleed pb?

Answer 25

1) Over temperature and pressure
2) Leak detected
3) Valve not closed when commanded (APU Bleed on, Engine start)