Hydraulics Flashcards
What controls the Hydraulics?
1 Hydraulic system monitoring unit HSMU
What is normal pressure for the 3 independent hyd systems?
3000 psi, 2500 psi for the RAT
What is the main hyd system?
Green system, 3 sources. engines and rat
What is the hyd priority valve?
Part of the green system, prioritizes flight controls in case of a low pressure situation. It will cut off pressure to:
Emergency Generator
Nosewheel steering
Landing Gear
On the SD HYD page, what is the white tick?
signifies 4.5 GAL. If quantity falls below, this turns to two amber bars.
Other than flight controls, what are powered by the blue hyd system?
(B for brake)
Alternate brakes
Parking brake
Brake accumulator.
Yellow system powers what?
All 3 hyd systems power various parts of the flight controls, other than that, the yellow powers cargo doors and flaps.
Can elec hyd pumps replace the engine driven pumps?
No, and they are for temporary use only.
What are the Pbs for controlling the hyd pumps?
Top button, cycles between AUTO/STBY and ON
Bottom button turns the pump off. Or in other words, turns off the AUTO/STBY function
If the pump is selected on, it would need to be pushed into the AUTO or STBY mode before being selected off.
Only use the lower off Pb when directed by ECAM or QRH.
When does the green electric pump automatically turn on?
When an engine has failed, and the gear is selected up. It then will turn on for 25 seconds in order to retract the gear in the required time.
When will the blue electric pump turn on?
When engine 1 has failed
and Either PRIM 1 or 3 has failed.
This is to ensure that at least 2 actuators are operating for rudder authority.
When does the Yellow elec pump turn on?
Engine 2 failure, and flap lever not at 0.
This is to ensure flaps can be retracted fast enough at accel altitude.
In this case the Green elect pump will come on for 25 secs while gear is retracted. The yellow will shut off during this time and turn on again after the green turns off. The yellow will remain on until engine shut down.
The pump also comes on when the cargo door is opened.
you will see a blue ON light. The leak measurement valve light also turns on at this time.
What is the Rat for and when will it deploy?
It is a back up pump for the green system in order to power flight controls and the emergency gen.
Will deploy automatically if engine 1 and 2 are lost
or if Green and yellow or green and blue are low level.
only can be stowed by mx.
min speed is 140
