Pneumatics Flashcards
How can the bleed air system be supplied?
Engine compressor bleed (5th/9th stages), APU or external pneumatic supply
Should DUAL BLEED illuminate what could it indicate?
APU Bleed switch is open with an engine bleed switch
With an enine bleed switch OFF what status will the isolation valve be if the switch was in AUTO?
Open
If an external pneumatic supply is connected to the aircraft and the isolation valve is selected to CLOSE, what indications will be shown on the duct pressure gauges?
The left duct will show zero and the right duct will show pressure
What could cause BLEED TRIP OFF light to illuminate?
Excessive engine bleed pressure or temperature. The valve will close automatically.
Should an air leak occur in the APU bleed duct, what indications would be given?
A left WING BODY OVERHEAT light would illuminate
Which system alerts crew to leaks from the bleed air duct?
Wing Body Overheat indication
At high engine power settings where does the pneumatic system receive its air supply
5th Stage
Where does preconditioned external air enter the cabin conditioning system?
Mix manifold directly
Which packs can the APU supply on the ground and in the air?
Two packs on ground and One pack in air
Position of ram air doors in cruise
Modulate between open and closed
Which modes can the Cabin Pressure Controller operate in?
Auto, Alternate, Manual
What is the purpose of the pressure relief valve and what pressure?
Provide safety pressure relief by limiting diff pressure to max 9.1PSI
The pressure system has two CPCs how is the primary controller selected for each flight?
Automatically sequenced after each flight with no crew input required
Diff pressure <FL280
7.45PSI
