36 - Pneumatic Flashcards
What does the Pneumatic system supply HP air for?
Air conditioning Engine start Anti ice Water pressurisation Hydraulic reservoir pressurisation
What stage does the air bleed come from?
Intermediate stage of the HP compressor
What happens if pressure from the IP stage is too low?
System bleeds air from the HP stage
When does the HP valve close automatically?
Low upstream pressure
Excessive upstream pressure
When does the bleed downstream of the HP and IP close pneumatically?
When upstream pressure is below 8PSI
If there is return flow
When does the bleed valve downstream of the HP and IP junction close electrically?
Bleed pb switch off
Fire push button pushed
BMC closes it (Bleed Monitoring Computer)
What percentage does the APU need to be running at to provide bleed air?
95%
When does the air cross bleed open when it’s in auto mode?
When the system uses APU air
When does the pre cooler inlet pressure become amber?
When it’s below 4PSI
When does the pre cooler outlet temp go amber?
Above 290 degrees for 5 seconds
What are the three sources of HP air?
Engine Bleed
APU
HP ground connection
What temperature does the pre cooler regulate the temp to approx.?
200 degrees
