Hydraulics Flashcards
HYD: Ground spoilers
System A
HYD: What is the difference in supply volume between engine and electric hyd pumps?
Engine driven pumps supply approximately 6 times the fluid volume of the related electric motor-driven pump
HYD: Yaw damper
System B
HYD: Describe a system B electric driven pump leak
Indicated quantity decreases to 0 and pressure is lost. However a standpipe ensures sufficient quantity for PTU operation.
HYD: Landing gear
System A
HYD: REFILL indication (RF) (white) appears
Hydraulic quantity below 76%
Note: valid only when aircraft is on ground with both engines shutdown or after landing with flaps up during taxi-in
HYD: Rudder
System A/B
HYD: Alternate brakes
System A
HYD: Autopilot B
System B
HYD: Hydraulic A/B pressure minimum
2,800 psi
HYD: FLT CONTROL switches - describe STBY RUD position
- closes flight control shutoff valve
- corresponding HYD system pressure is isolated from aileron, elevator feel and rudder
- activates sby pump (arms sby hyd LOW PRESSURE light) and pressurises the sby rudder PCU
- illuminates the STBY RUD ON light
- thrust reverser will be powered by sby hyd system if necessary
- yaw damper switch can be turned back on if both switches are placed in STBY RUD
HYD: Describe the Power transfer unit
Supplies the additional volume of hyd fluid needed to operate autoslats and leading edge flaps and slats at normal rate when sysB eng-driven hyd pump volume is lost.
Uses sys A pressure to power a hyd motor driven pump which pressurises sys B hyd fluid.
Operates when all the following conditions exist:
Sys B eng-driven pump hyd press below limits
Airborne
Flaps Less than 15 but not up
SFP flaps not up
HYD: Brake pressure minimum
2,800 psi
HYD: Flight spoilers
System A / System B
Two on each wing for A / B
HYD: FLT CONTROL switches - describe position OFF
- closes flight control shutoff valve
- corresponding HYD system pressure is isolated from aileron, elevator feel and rudder
- yaw damper switch flips off when B system switch selected OFF
- respective LOW PRESSURE and FEEL DIFF PRESSURE light illuminate
HYD: No. 2 thrust reverser
System B
HYD: Describe a system A electric driven pump leak
Fluid quantity decreases to 0 and all pressure is lost.
HYD: Power transfer unit (PTU)
System A
HYD: Describe a system A engine driven pump leak
Standpipe in the reservoir prevents total system fluid loss. With fluid level at the top of the standpipe, the reservoir quantity indicates approx 20%. System A pressure is maintained by the electric pump
HYD: Trailing edge flaps
System B
HYD: Ailerons
System A/B
HYD: Normal nose wheel steering
System A
HYD: Alternate nose wheel steering
System B
HYD: Autopilot A
System A
