Hydraulics Flashcards
When do the hydraulic demand pumps operate?
Respective fuel control switch is in CUTOFF, respective engine pump output pressure is low
Where can hydraulic fluid quantity be checked
Status page
An amber Demand Pump low PRESS light on the hydraulic panel indicates what?
Demand pump operating and output pressure is low or demand pump selector positioned to OFF or AUX
What does an amber SYS FAULT light on the hydraulic panel indicate?
Low hydraulic reservoir quantity or low hydraulic system pressure
If the HYD PRESS DEM 4 EICAS advisory alert message on the Freighter illuminates shortly after engine 4 has been started what does that indicate?
The system 4 demand pump selector is positioned to AUX
In normal operations, why is hydraulic system 4 pressurized first?
To prevent transfer of fluid from hydraulic system 2 or 1 to hydraulic system 4
How are hydraulic demand pumps 1 and 4 powered?
Pneumatic
Which hydraulic system powers the right autopilot servo?
2
A magenta RF next to a hydraulic fluid quantity indicates what?
Can be observed on the Status Page or Hydraulic synoptic and indicates refill is required
How are hydraulic demand pumps 2 and 3 powered?
Electric
What do the magenta letters RF indicate on the hydraulic synoptic?
Refill of the respective hydraulic system is required
A magenta LO next to a hydraulic fluid quantity indicates what?
Can be observed on the Status Page or Hydraulic Synoptic and indicates low reservoir quantity
IF an engine fire switch is pulled, the related hydraulic fluid shutoff valve closes. What is the status of the related engine driven hydraulic pump and hydraulic demand pump?
EDP depressurizes and demand pump operates providing pressure to the system.
What hydraulic system powers the left autopilot servo?
3
Why are the hydraulic system reservoirs pressurized by the bleed air system?
To prevent pump cavitation and ensure positive flow during high demand conditions
The hydraulic SYS FAUL lights are flashing on and off, the >HYD QTY LOW X EICAS advisory messages are appearing and disappearing and the EICAS hydraulic quantity indications are decreasing and increasing. This would indicate what condition?
HYQUIM failure
When will the AUX 4 hydraulic pump operate with the selector in AUX?
On the ground and engine driven pump 4 not pressurized
NWS and body gear steering are powered by which hydraulic system?
1
Assuming engine is running and EDP pressure is good, what condition would cause only hydraulic demand pumps 1 and 4 to run in the air with the selector in AUTO?
Flaps out of up
Assuming engine is running and EDP pressure is good, what condition would cause only hydraulic demand pumps 1 and 4 to run on the ground with the selector in AUTO?
Flaps in transit
With the selector in AUTO, any hydraulic demand pump will operate for either of two conditions. What are the two conditions?
Engine driven pump output pressure low or related fuel control switch is in cutoff
What does hyd system 1 normally power?
Body gear, body gear and nose wheel steering, inboard trailing edge flaps, alternate brakes, primary flight controls
Which system powers the center autopilot servo?
1
What does the engine driven pump PRESS light indicate?
Low engine hydraulic pump output pressure
