Hydraulics Flashcards
Digital HYD quantity read out range
0 to 106%
Normal pressure HYD
3000PSI
Max HYD pressure
3500PSI
When does RF indication show and when does it appear on the MFD
When quantity drops below 76%
Shown when the a/c is on the ground with both engines shutdown or after landing with flaps up during taxi in
When FLT CONTROL switch is placed to STBY RUDDER
Activates standby pump and opens standby rudder shutoff valve to pressurise the stanby rudder PCU
amber LOW PRESSURE underneath FLT CONTROL switches
Low HYD system pressure to ailerons, elevator and rudder
System A HYD system supplies
Ailerons, Rudder, Elevator, Elevator feel
Flight spoilers
Alternate brakes
L/d gear
Ground spoilers
L/d transfer unit
No1 thrust reverser
Nose wheel steering
A/p A
PTU
System B HYD system supplies
Ailerons, Rudder, Elevator, Elevator feel
Slats and trailing edge flaps
Yaw damper
Brakes
Autoslats
No2 thrust reverser
Flight spoilers
Alternate nose wheel steering
A/p B
L/g transfer unit
How much more does the Engine driven pump supply in volume than the electric driven pump
6 times
Positioning the ENG driven pump to OFF
Isolates fluid flow from the system components
Activates a solenoid blocking valve
Continues to rotate as long as the engine is operating
HYD fluid is also used for cooling and lubrication of the pumps. Where are the heat exchangers located
Passes through a heat exchanger before returning to the reservoir. System A located in main tank No1. System B = Main tank No2
Min fuel for ground operation of electric driven HYD pump
760kgs in the related tank
System A HYD leak un engine driven pump lines what will be displayed
Standpipe in the reservoir prevents total system loss. Quantity will indicate 20% full.
System A pressure is maintained by the electric pump
System A HYD leak in electric driven pump and lines what will happen?
Quantity in reservoir slowly decreases to 0 and all system pressure is lost
System B HYD leak in either pump or line what will happen
Quantity decreases until it indicates 0 amd pressure is lost
Standpipe fluid is sufficent to operate the PTU
Leak in system B does not effect the standby system
When does the PTU operate
System B engine driven pump drops below limits
Airborne
flaps are less than 15 but not up (YA573 to YW097)
flaps are not up (everyone else)
What system supplies the L/g gear transfer unit when system A engine driven volume is lost
System B if these conditions exist
Airborne
No1 engine RPM drops below limit value
L/d gear postitioned UP
Either main l/d gear is not up and locked
What does the standby HYD system power
Rudder
Thrust reversers
LE flaps and slats (extend only)
Standby yaw damper
Positioning the ALTERNATE FLAPS to ARM
Activates standby electric motor driven pump
Closes TE flap bypass valve
Arms ALTERNATE FLAPS switch
Allows standby system to power LE flaps and slats
Automatic operation of Standby HYD is caused by what conditions
Loss of system A OR B
Flaps extended
Airborne
Wheel speed greater than 60kts
FLT CONTROL switch A or B ON
or
The main PCU force flight monitor trips
Standby HYD system leak
Reservoir decreases to 0
LOW QUANTITY light illuminates when it is half empty
System B operates normally ut indication decreases and stabilises at 70% full
Cavitation/foaming can occur at high altitudes what signs in the f/d if foaming has occured
Blinking of LOW PRESSURE lights and pressure fluctuations
MASTER CAUTION and HYD may illuminate momentarily
