Air Systems Flashcards
What sources can supply the pneumatic system with pressurized air?
- The 6th or 10th stage of the left and right engine compressors
- The APU
- An external ground air source
What is the function of the Air Conditioning System Controller (ACSC)?
Bleed source selection Valve operation Air distribution
What is the location of the engine start external ground air connector?
Aft left side of the fuselage
Where is the external ground air pressure (high pressure) monitored from the cockpit?
On the ECS synoptic page
What is the regulating function of the engine bleed valve (PRSOV)?
It limits the engine’s discharge pressure to 45 psi +/- 3 psi.
How can the pilot manually close the bleed valves?
By using the manual portion of the Bleed Air Control Panel
What is the function of the high pressure valve (HPV)?
To supply 10th stage pressure to the pneumatic system when system demands exceed the capacity of the 6th stage.
What is the function of the APU Load Control Valve (LCV)?
It opens to provide bleed air for ECS and engine starts It modulates to control the amount of bleed air taken from the APU
What unit controls the operation of the APU Load Control Valve (LCV)?
The APU Electronic Control Unit (ECU)
Which side of the bleed air manifold does the APU LCV deliver pneumatic pressure?
Left
What is the function of the Isolation Valve?
It connects the left and right sides of the bleed manifold.
When does the Isolation Valve automatically open?
During engine starts During automatic transfer of bleeds from the engines to the APU
When does the isolation valve automatically close?
During transfer of the bleeds from the APU to the engines
How can the pilot manually operate the Isolation Valve?
Move the ISOL toggle switch on the Bleed Air Control Panel to the desired position Move the rotary selector switch on the Bleed Air Control Panel to MANUAL
What bleed source will supply the manifold if the APU and both engines are operating when on the ground with the bleed valve selector in auto mode?
The APU
When does the Air Conditioning System Controller (ACSC) switch from the APU to the engines as a bleed source after departure?
When the thrust levers are retarded from the takeoff detent
When does the ACSC switch from the engines to the APU as a bleed source during approach?
Flaps are greater than 20 degrees or the landing gear is down.
Is the APU capable of supplying bleed air to the anti-ice system?
No
What will occur if the APU is supplying bleed air to the manifold and either the cowl or the wing anti-ice switch is selected on with both engines operating?
The ACSC will close the APU LCV and transfer the bleed loading to the engines
What will occur if the APU is supplying bleed air to the manifold and either the cowl or the wing anti-ice switch is selected on with both engines shutdown?
The ACSC will close the APU LCV The bleed manifold will become depressurized A BLEED MISCONFIG caution is displayed on the Primary Page
What occurs to the bleed air flow when the engine START switchlight is pressed?
The Isolation Valve opens Both Air Conditioning Pack Valves close The associated Start valve opens The engine’s Air Turbine Starter engages
What is the function of the Bleed Air Leak Detection System?
The Bleed Air Leak Detection System monitors the bleed air and anti-icing ducts for leakage.
What is the function of the Anti-Ice Detection Controller (AILC)?
To continuously monitor for failure of the bleed air or anti-icing ducts and the integrity of both channels of the detection system.
What is the function of the CLSD position of the Bleed Valves Selector located on the Bleed Air Control Panel?
It allows the pilot to override the ACSC and close all aircraft bleed sources except air from an external air source.
What is the function of the AUTO position of the Bleed Valves Selector located on the Bleed Air Control Panel?
It allows the ACSC to control all aspects of bleed air management.