Utility Hydraulic System Flashcards
What must you do in order to use APU start accumulator pressure to operate a subsystem?
Open the Emergency Utility Pressure Valve
What are 5 of the nine systems that are operated by the utility hydraulic system?
- Engine Start
- Center Hook Release
- Power steering
- Swivel Locks/ Centering Cam
- Wheel Brakes
- Hoist/ Rescue Winch
- PTU’s
- APU Start
The Utility Hydraulic Pump provides a constant output pressure of _______ with a variable flow rate of ______ gallons per minute based on 100% RRPM.
3000 PSI, 16.5
How is the APU start accumulator re-pressurized after APU start?
APU Motor/Pump
What should you do if the UTIL HYD SYS caution light does not go out within 30 seconds after the APU ON caution light comes on?
Shut down the APU
What is the emergency procedure when the UTIL HYD SYS caution light is illuminated and fluid loss is evident?
- Isolation Switch - OFF
- LAND AS SOON AS POSSIBLE
What are the four sources of pressure for the utility hydraulic system?
- APU Start Accumulator
- APU Motor/Pump
- Utility Hydraulic Pump
- Aux Ground Power Unit
How much pressure should be in the APU start accumulator when starting the APU?
3000 PSI
What should the pressure read on the utility reservoir pressurization accumulator gauge during preflight?
2500 to 3500 PSI
How would a complete loss of fluid be indicated if the UTIL HYD SYS caution light is on?
Fluid level indicator on the maintenance panel
Where does the pressure transmitter on the pressure control module send its signal?
To the gauge on the maintenance panel
When can the Hydraulic system be serviced, on the ground, in-flight, or both?
Both
What action should you take if either the pressure or return filter contamination button is out on preflight?
Replace the filter
What should the pilot do immediately after the UTIL HYD SYS caution light comes on?
Have crewmember check fluid level and temp
At what differential PSI will the indicator button pop on the pressure control module?
75 PSI +/- 10
The APU start accumulator is divided into four sections. What are the four sections?
Gras Pre-Charge, Pressurized Hydraulic Fluid, holds return Fluid, Allows Atmospheric pressure to vent
What should the crewmembers do if any abnormal indications appear on the maintenance panel?
Notify the pilots
What component maintains 60 PSI on the supply side of the Utility hydraulic reservoir?
Utility Reservoir Pressurization Accumulator
The Utility pump provides _______ PSI for system operation.
3000
The APU Motor Pump provides _______ PSI for system operations
3350
What is the purpose of the bleed relief valve on the utility reservoir/cooler assembly?
Closes at 20 PSI and allows fluid to enter the cooler
What is the emergency procedure when the UTIL HYD SYS caution light is illuminated and pressure is not restored after starting the APU?
Land as soon as possible
