Hydraulic Power Flashcards
Standby Hydraulic Pump power source
normal - right 115 volt variable AC bus
backup - left 115 volt variable AC bus
Backup pressure source to hydraulic system 1
AC electrically driven Standby Hydraulic Pump
Backup pressure source for hydraulic system #2
Power Transfer Unit powered by hyd system #1
3 hydraulic system purpose
provides hydraulic pressure to the left and right inboard elevator PCUs when necessary
DC Motor Driven Pump maintains accumulator pressure within…
2600 psi to 3250 psi.
When does the #3 hydraulic system automatically operate?
1 and/or #2 main hydraulic system failure, or failure of both engines
3 hydraulic system power source
gas charge accumulator pressurized by a DC Motor Driven Pump (DCMP)
1 hydraulic system provides power to:
Flaps Anti-skid Brakes Inboard Roll Spoilers Rudder (Lower PCU) Elevators (Outboard PCUs) PTU
2 hydraulic system provides power to:
Landing Gear Outboard Roll Spoilers Nose Wheel Steering Emergency/Parking Brake Rudder (Upper PCU) Elevators (Center PCUs)
4 hydraulic system provides power for:
Alternate Landing Gear Extension system
Minimum hydraulic quantity for dispatch
40%
Hydraulic reservoir capacities
1 8 quarts
2 12 quarts
3 2.6 quarts
4 1.2 quarts
Location of #1 hydraulic reservoir
left engine nacelle
Location of #2 hydraulic reservoir
right engine nacelle
Location of #3 hydraulic reservoir
environmental compartment (high up, aircraft left)
Location of #4 hydraulic reservoir
right side nose compartment
When will the Standby Hydraulic Pump automatically activate?
no. 1 engine fails
The PTU will produce pressure in the no. 2 hydraulic system if:
no. 1 engine driven pump is producing normal pressure and no. 2 hydraulic system has hydraulic fluid
When will the PTU operate automatically in the air?
no. 1 engine driven pump is producing normal pressure
no. 2 hydraulic system has hydraulic fluid
flaps are selected to more than 0 OR
no. 2 hydraulic system has lost pressure OR
no. 2 engine oil pressure is low
When will the PTU operated automatically on the ground?
no. 1 engine driven pump is producing normal pressure
no. 2 hydraulic system has hydraulic fluid
parking brake released
flaps are selected to more than 0
When does the Hydraulic System Isolation valve close?
inadequate fluid quantity
When the #1 hydraulic system HYD ISO valve closes, hydraulic power is only available to:
Flaps Rudder Elevator PTU lose - anti-skid/main wheel brakes, inboard elevator
When the #2 hydraulic system HYD ISO valve closes, hydraulic power is only available to:
Rudder
Elevator
lose - landing gear, outboard roll spoilers, nose wheel steering, emergency/parking brake
How are the #1 and #2 hydraulic systems cooled?
oil-to-fuel heat exchanger located in the collector bay
When does the #1 hydraulic system priority valve close?
1 system hydraulic pressure low
Closing of the priority valve shuts off hydraulic power to what?
Flaps and PTU
maintains - anti-skid/main wheel brakes, inboard roll spoilers, rudder, elevator
1 or #2 HYD ISO VLV caution light
isolation valve switch has moved hydro-mechanically to the isolate position
Normal hydraulic pressure
3000 psi
Brake Pressure for Engine Start
1000, Left, 500 right
