Hydraulic System Flashcards
Describe operation of the utility hydraulic system.
If the combined system pressure drops below 800 psi, the utility system acts as a backup, drawing fluid from the combined hydraulic system reservoir, and pump motor operation from the flight hydraulic system pressure
From where does the auxiliary hydraulic system pump draw fluid for operation?
From the auxiliary section of the combined hydraulic system reservoir
When does the blue “FLT HYD HOT” CAS message illuminate?
When temp of fluid in flight hyd system > 220˚ F
If the flight hydraulic fluid is hot, what is the effect on the utility system operation?
Utility system operation will be unavailable unless the utility pump is hard-selected ON
What action is required to most accurately determine combined and flight hydraulic system quantities?
The hydraulic systems must be pressurized.
If an amber “CMB HYD FAIL” CAS message illuminates, what is the affect on the utility hydraulic pump?
The utility hydraulic pump will automatically turn on, if ARMED. When the combined system pressure drops below 800 psi
If a blue “FLT HYD HOT” CAS message illuminates while the utility hydraulic pump is in use, what is the affect on the utility hydraulic pump?
The utility pump will automatically turn OFF unless it is hard-selected to ON
If the combined hydraulic system pump fails and hydraulic fluid is still available, what systems are lost?
Left thrust reverser
Standby electrical power system (ABEX / HMG)
With a loss of combined system fluid, what systems are not available?
- U tility Hydraulic System
- N ose wheel steering
- N ormal landing gear operation
- S tall barrier system
- A BEX / Stby Elec Pwr Sys / HMG
- T R (LH)
With a loss of the flight hydraulic system pump and/or fluid, what systems are not available?
- Yaw damper and auto pilot
- Utility hydraulic pump operation
- TR (RH)
What is indicated by a green “REV ARM” light on touchdown?
TRs are armed and available for use, as sensed by
Idle power levers and:
- nutcrackers in ground mode (WOW)
OR
- wheel-speed spin-up if ASC 166 (>65)
Which hydraulic systems are capable of providing normal braking with anti-skid protection?
Combined
Utility
Auxiliary
What is the normally configured position of the utility pump in flight?
ARMED
With a loss of combined hydraulic fluid, what is the primary reason that the aux hydraulic pump is selected ON prior to landing?
To allow the ground spoilers to operate normally
- Braking is secondary, as braking should occur when the brake pedals are depressed with the aux pump in the ARMED position
What action is required if a red “REV UNLOCK” CAS message illuminates in flight?
- Reduce power on the affected engine
- Select the emergency stow switch to STOW
- Maintain a maximum airspeed of 200 KCAS
- Then run the QRH
How is the auxiliary hydraulic pump powered?
DC powered through the battery tie bus
How can the utility hydraulic system be actuated?
- Manually by the pilot
- Automatically in the event of a combined hydraulic failure, if ARMED
When armed, what conditions will cause the Auxiliary Hydraulic Pump to turn ON automatically?
- Either Nutcracker in the Ground Mode
- Combined and Utility pressures < 1500 psi (HMG)
- Toe Brake Pedal depressed > 10˚ (BBW)
What capabilities are lost if you lose the Flight Hydraulic System pressure?
- Yaw Damper
- Auto-pilot due to Yaw Damper
- Right Thrust Reverser
- Utility Pump Motor
The Utility Pump is driven by Flight Hydraulic System pressure and uses Combined Hydraulic System fluid. When armed, what will cause it to turn ON automatically?
CAS Message indicating a combined system failure or combined system pressure falling to < 800 psi.
When the Utility Pump is armed, what conditions will prevent automatic Utility Pump operation?
CAS Message Indicating Flight Hydraulic System fluid temperature is > 220° F
The Auxiliary Hydraulic pump is capable of powering which components? (6)
- Main Entrance Door
- Wing Flaps
- Brakes (Normal Antiskid)
- Parking/Emergency Brakes
- Landing Gear/Doors (ground only)
- Cargo Door (military aircraft only)
Anti-Skid Braking is available from which hydraulic systems?
Combined
Utility
Aux
Type of Hydraulic Fluid used?
Exceptions?
- Skydrol
- Gear struts use 5606
