Hydraulics Flashcards
What is normal system pressure?
When RAT supplying?
When does PTU kick in? Does it work on ground?
3000 PSI
2500 PSI
When pressure differential over 500 PSI. Works on ground.
What are system accumulators for?
Maintain constant pressure by covering transient demands
What do priority valves do?
Cut off hydraulic power to heavy load users in case of low system pressure
Where are the leak measurement valves located on each system?
Can they be closed manually?
Upstream of the primary flight controls
Yes, buttons on maintenance panel above
Where are the Fire Shutoff Valves located in relation to the engine pumps?
Upstream of both engine pumps
What are the three types of filter, and where are they installed?
HP Filter
* On all 3 systems
* Reservoir filling system
* Normal braking system
Return Line Filter
* Each system
Case Drain Filter
* Both Engine Pumps
* Blue Electric Pump
allow maintenance to monitor pump wear
Why would the ENG 1 (2) PUMP pb show amber FAULT lt?
When does the light go out?
- Reservoir level low
- Reservoir overheats
- Reservoir air pressure low
- Pump low pressure
inhibited on ground, engines off
Extinguished when pressed OFF, except for an overheat (until over)
B+Y ELEC PUMP pb FAULT lt illuminates for same reasons as ENG PUMPs, plus what other reason?
Pump overheat
When does the B ELEC PUMP run when in AUTO?
Can the Y ELEC PUMP run when OFF?
In flight if AC power avail
On ground if one engine is running or crew has pressed B PUMP OVRD
Yes, Y ELEC can run even when selected OFF when ground crew open/close cargo doors
When PTU in AUTO, when will it run?
When is it inhibited?
What happens when selected OFF?
FAULT lt?
- G/Y pressure differential of over 500 PSI
- Test during second engine start
Inhibited during first engine start
OFF: valves either side of pump close
FAULT: G or Y FAULT
(RSVR OVERHEAT, AIR PR LO, LO LVL)
stays on for overheat
What is the reservoir quantity for Green/Yellow/Blue?
What is the low level warning?
Green 14.5 ℓ
Yellow 12.5 ℓ
Blue 6.5 ℓ
G+Y margin 2.6ℓ, B 1.6ℓ)
Green/Yellow: 3.5ℓ
Blue: 2.4ℓW
Where is the RSVR OVHT measured from?
Which pumps would you see a simple OVHT on?
Return inlet to reservoir
Electric pumps for Yellow and Blue
What do the following RAT indications mean?
White hollow arrow
Green solid arrow
Amber solid arrow
White hollow- RAT stowed
Green solid- RAT not stowed
Amber solid- RAT pump not avail
At what pressure will the system label and arrow become amber?
When will the number (1 or 2) next to the engine pump symbol turn amber?
Below 1450 PSI
When the associated engine’s N2 is below IDLE
