36 Pneumatic a321

Question 1

what are the a321 pneumatic consumers

Answer 1

• antiicing (wing)
• air con
• pressurize hydraulic resevoirs
• pressurize potable water tank
• engine starting

Question 2

what is the normal operation postition of the crossbleed valve?

Answer 2

closed -> isolation of systems

Question 3

how many engine bleed systems are there?

Answer 3

2 -> one for each engine

Question 4

draw a schematic of the a321 pneumatic system

Answer 4

see pic

Question 5

what are key components to include on a schematic of the ba321 pneumatic system?
what are separate locations to label that the air goes?

Answer 5

• fain air valve
• HPV (high pressure valve)
• IPC (IP check valve)
• PRV (pressure regulator valve)
• OPV (over pressure valve)
• precooler
• bleed air valve

air goes to:

• to engine starter
• to wing antiicing
• to aircon
• to other systems

Question 6

draw the diagram of the relationship between the engine speed and the pressure of the pneumatic system

Answer 6

see pic

starting from lowest engine speeds:

• at HP pressure until nominal value of HPV
• stays at nominal HPV until IP reaches HPV nominal value
• at IP pressure until nominal vale PRV

Question 7

what does the over pressure valve do?

Answer 7

closes if pressure is above a certain value

Question 8

what does the pressure regulating valve do ?

Answer 8

controls if bleed air is coming from HP or IP

Question 9

how is the temperature controlled?

Answer 9

air from the fan air exchanges in the precooler with the high pressure bleed air to reduce temp from 400 to 200 deg C

Question 10

where does the high pressure air come from in flgith and on ground?

Answer 10

in flight: engine bleed air is main
-APU is also able to supply in flight

ground:
- APU
- ground connection

Question 11

how many BMC are there? how many in normal operation?

Answer 11

2. each is primary for its own bleed system

Question 12

where are the BMC located

Answer 12

avionics compartment

Question 13

how is the pneumatic system usually controlled?

Answer 13

automatically -> through the BMCs

Question 14

what , where, why is the TCT?

Answer 14

what: temperature control thermostat
where: immideatly after precooler
why: to give information to fain air valve about cooling needs

Question 15

how is the pneumatic system turned off and how/ why would this happen?

Answer 15

how: closing of PRV

why: (pneumatically)
-upstream low pressure
(electrically)
-ENGINE BLEED TO OFF
-BMC deteects failure (temp, pressure, leak
-BMC detects APU bleed on

Question 16

how are the HPV and PRV connected?

Answer 16

they are pneumatically connected so the HPV closes when the PRV closes

Question 17

can the APU bleed air and the engine bleed air be used at the same time?

Answer 17

no -> the APU bleed control valve acts as a shut off for the two PRVs

Question 18

how is APU bleed air controlled (buttons, computers)

Answer 18

there is a button on the cockpit with the APU BLEED to be turned on. This will activate the APU Electronic Control Box (ECB)

Question 19

where are ducts for APU bleed and ground bleed in relation to the crossbleed valve?

Answer 19

left

Question 20

what type of valve is the crossbleed valve? What are its typical components?

Answer 20

butterfly valve

double motor (for for automatic and one for manual operation)

Question 21

what are teh two forms of operation f teh crossfeed valve

Answer 21

automatic and manual

Question 22

what is the basic principle of the leak detectino system?

Answer 22

overheat sensing elements