Pneumatics Flashcards
T or F: the pneumatics system provides air for airstair door seal pressurization.
True.
T or F: the pneumatics electronic control unit (ECU) uses left and right digital channels for control with no associated backup channels.
False, there are analog backup channels.
Prior to engine start, what sources provide bleed air for the pneumatic system?
APU.
When BLEED 1 and BLEED 2 switches are selected OFF, what is the result in the associated bleed air system?
The ECU closes the associated high pressure shutoff valve and associated nacelle shutoff valve.
How many engine bleed ports are used to supply bleed air to the pneumatic system?
Four. One high pressure and one low pressure per engine.
T or F: after engine start, bleed air is primarily provided by both engine bleeds and the APU bleed at the same time.
False.
T or F: bleed air is continuously supplied to the deicing system, regardless of flight deck switch positions.
True.
T or F: if the DC starter/generator were to fail, the engines can still be started using APU bleed air.
False.
If one or more protective bleed air sensors exceed normal values, what will the ECU system do?
Automatically shut down the system.
During lower power settings, the ECU uses which port(s) for bleed air?
High pressure.
During higher power settings, the ECU uses which port(s) for bleed air?
Low pressure.
T or F: prior to engine start, the bleed control switches should be in the OFF position.
True.
When the engines are running, the bleed control switches should be set to what position?
BLEED 1 and BLEED 2.
How many different positions are there on the bleed flow control selector?
Three: min, norm, max.
Which of the following does NOT use bleed air?
Propeller pitch control and engine starting.
Which of the following is NOT a condition that will cause the pneumatics ECU to automatically shut down the affected bleed system?
these will: over temperature, over pressure, bleed leak.
The pneumatic ECU uses ____ to determine whether the HP port or the LP port will be used for bleed air.
Power lever condition.
Which conditions will cause the ECU to shut down the bleed air system?
Over temp, over pressure, bleed leak.
T or F: APU bleed air and engine bleed air can supply bleed air to the environmental system simultaneously.
False.
