Pneumatics Flashcards
When do the bleed valves fail safe closed?
- the engines shut down
- ASCS control signal is removed (air conditioning system controller)
- engine fire push switch
The bleed valves regulates engine discharge pressure to what?
45 PSI +/- 3
Where is bleed air extracted from?
6th and 10th stages
When is 10th stage bleed air used?
When system demands exceed the 6th stage
What does the APU LCV fail to?
Fails closed
When is the isolation valve automatically opened?
- APU LCV opened
- cross bleed engine starts
- transfer of bleeds between APU and engines
Bleed valve closes if the manifold pressure exceeds what PSI?
60 PSI
With engines and APU running, which has priority in supplying bleed air on the ground?
APU
Can engines and APU supply bleed air at the same time?
No
Can the APU supply bleed air to the engine anti-ice?
No
On takeoff when does the bleed air switch from the APU to the engines?
With gear and flaps retracted and the thrust levers retarded from the takeoff detent
On approach when will the bleed air switch from the engines to the APU?
When flaps are greater than 20° or the landing gear is down
When is the ISOL and BLEED SOURCE switch powered?
Only when the BLEED VALVE selector switch is placed in manual
