Hydraulic System Flashcards
(29 cards)
How many systems?
3 (A, B, Standby)
System A Componets
Ailerons
Rudders
Elevator and Elevator Feel System
Flight Spoilers
Landing Gear
Power Transfer Unit
Nosewheel Steering
Ground Spoilers
Alternate Brakes
No. 1 Thrust Reversers
Autopilot A
UARRSI door
Left Weapon Bay Door
Right Weapon Bay Door (Alternate)
System B Powered Componets
Ailerons
Rudder
Elevator and Elevator Feel
Flight Spoilers
Leading Edge Flaps and Slats
Normal Brakes
No. 2 Thrust Reverser
Autopilot B
Alternate Nosewheel Steering
Landing Gear Transfer Unit
Autoslats
Yaw Damper
Trailing Edge Flaps
Left Weapons Bay Door (Alternate)
Right Weapons Bay Door
Standby System Componets
Thrust Reversers
Rudder
Leading Edge Flaps and Slats (Extend Only)
Standby Yaw Damper
How many pumps are there?
4 (2 Electric 2 Engine Driven)
How much stronger are the engine pumps than the electric?
4 times
How to stop the engine driven pumps from rotating?
Never stop. Switching them off isolates the fluid flow
Leak in A
If in Engine Driven Pump: Standby Pipe prevents total loss (20%) and pressure is maintained by electric pump
If in Electric Pump: 0% Total Fluid Loss
Leak in B
Total Fluid loss. One standby pipe to operate power Transfer unit. Doesn’t affect standby system.
Standby Leak
0% on Standby, Reservoir is approximately half full. System B indicates 72%
When is Power Transfer Unit used?
B Leaks
What does the Power Transfer Unit do?
Operates leading edge flaps and slats from system A pressure to operate the hydraulic motor driven pump
When is the Power Transfer Unit Automatic
Hyds B pressure drops below limits
Airborne
Flaps 1-25
When is Landing Gear Transfer Unit used?
When A leaks
What does the Landing Gear Transfer Unit Do?
Uses B hydraulic pressure to raise the landing gear
When is the landing gear transfer automatic?
System A below limits
No1 engine RPM drops below a limit value
Landing Gear Lever Up
Either main landing gear not up and locked
When does foaming occur?
System is not properly pressurized at high altitudes
How is foaming identified?
Pressure fluctuation and blinking low pressure light
What pressure are you looking for when turning the electric hydraulic pumps on?
Minimum of 2800 psi
How is the standby system activated?
Manually: Positioning flight control to standby rudder
Automatically: Loss of A, Flaps extended, airborne or wheels above 60 knots and flight control switch A or B is on, or main power control unit force flight monitor trips.
What does positioning Standby Rudder on Do?
Activates Tandby electric motor driven pump
shuts off related hydraulic system pressure to elevator, aileron and rudders (closes flight control shutoff valve)
Opens standby rudder shutoff valve
Deactivates related flight control low pressure light
allows standby system to power rudder and reverse thrust
Illuminates Standby rudder on, master caution and flight control lights
What does arm alternate flaps switch do?
Activates standby electric pump
Closes trailing edge flap bypass
Arms alternate flaps position switch
Allows standby system to power flaps slats and reverse
When is Auto Brakes armed?
90 knots
Normal Brake pressure
3000 to 3500
