Pneumatic Flashcards
What is the primary bleed source for pneumatics on the ground
APU
If the HPV opens will the system continue to supply 6th stage air to the manifold
No, because of a check valve. The higher pressure air would try to flow into the 6th stage area without check valve
Which valves automatically close during engine start
Flow Control Valve(PAK valves)
Which valves open during engine start
- Bleed isolation valve
- APU LCV (optional)
- Associated ATS valve (not controlled by ACSC)
What systems use bleed air
- ECS
- ATS
- Anti-ice
What is used to detect leaks and overheats
Dual loop system and temp sensors in wings and pressure transducers
When will bleed source switch from APU to engines on ground
When anti-ice is activated
When taking off with APU on and anti-ice off when will bleeds switch to engines
When thrust is below TOGA, gear is up, flaps are less than 20*
On approach with the anti-ice off when will bleeds switch from APU back to the engines
Landing bit - gear down or flaps greater than 20*
What valves does the ACSC control
PRSOV, LCV, HPV, ISOL
Can the ISOL switch be opened or closed manually
PSM 19-20-1
Only when the BLEED VALVE switch is selected to manual
On the EICAS ECS synoptic page, what would it mean if the bleed pressure indication was Amber
PSM 19-20-2
Bleed pressure is high or low
When in manual mode does ISOL switch override the systems protective features
No
When in manual mode does the ISOL switch restrict automatic operation of the ISOL for engine start
No
What controls if the system uses 6th or 10th stage bleed air
ACSC
