Hydraulic System

Question 1

What capabilities are lost if you lose the Flight Hydraulic System pressure?

Answer 1

Yaw Damper
Right Thrust
Reverser Utility Pump Motor
Auto-pilot due to Yaw Damper

Question 2

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?

Answer 2

CAS Message indicating a combined system failure or combined system
pressure falling to less than 800 psi.

Question 3

When the Utility Pump is armed, what conditions will prevent automatic Utility Pump operation?

Answer 3

CAS Message -
Indicating Flight Hydraulic System fluid
temperature is greater than 220°F

Question 4

When armed, what conditions will cause the Auxiliary Hydraulic Pump to turn ON automatically?

Answer 4

Either Nutcracker in the Ground Mode and Combined and Utility pressures less than 1500 psi (HMG) and
Toe Brake Pedal depressed greater than 10 degrees (BBW)

Question 5

The Auxiliary Hydraulic pump is capable of powering which components?

Answer 5

Main Entrance Door
Wing Flaps
Brakes
Main Door 
Parking/Emergency Brakes Landing Gear/Doors (ground only) Cargo Door (military aircraft only)

Question 6

Anti-Skid Braking is available from which hydraulic systems?

Answer 6

Combined Hydraulic System
Utility Hydraulic System
Aux Hydraulic System

Question 7

1. Describe operation of the utility hydraulic system.

Answer 7

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

Question 8

2. From where does the auxiliary hydraulic system pump draw fluid for
   operation?

Answer 8

From the auxiliary section of the combined hydraulic system reservoir

Question 9

3. When does the blue “FLT HYD HOT” CAS message illuminate?

Answer 9

When the temperature of the hydraulic fluid in the flight system exceeds 220º F

Question 10

4. If the flight hydraulic fluid is hot, what is the effect on the utility system
   operation?

Answer 10

Utility system operation will not be available unless the utility pump is
hard-selected to ON

Question 11

5. What action is required to most accurately determine combined and flight
   hydraulic system quantities?

Answer 11

The hydraulic systems must be pressurized

Question 12

6. If an amber “CMB HYD FAIL” CAS message illuminates, what is the affect on
   the utility hydraulic pump?

Answer 12

The utility hydraulic pump will automatically turn on, if ARMED

Question 13

7. 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?

Answer 13

The utility pump will automatically turn OFF unless it is hard-selected to ON

Question 14

8. If the combined hydraulic system pump fails and hydraulic fluid is still
   available, what systems are lost?

Answer 14

Left thrust reverser

Standby electrical power system (HMG)

Question 15

9. With a loss of combined system fluid, what systems are not available?

Answer 15

Left thrust reverser  
Standby electrical power system (HMG)  
Stall barrier system  
Nose wheel steering  
Normal landing gear operation  
(Utility Hydraulic System)

Question 16

10. With a loss of the flight hydraulic system pump and/or fluid, what systems are
    not available?

Answer 16

Right thrust reverser
Utility hydraulic pump operation
Yaw damper and auto pilot

Question 17

11. What is indicated by a green “REV ARM” light on touchdown?

Answer 17

The thrust reversers are armed and available for use, sensed by nutcrackers
switching to the ground mode, or through wheel-speed spin-up on most aircraft
and idle power levers.

Question 18

12. Which hydraulic systems are capable of providing normal braking with anti-
    skid protection?

Answer 18

Combined
Utility
Auxiliary

Question 19

13. What is the normally configured position of the utility pump in flight?

Answer 19

ARMED

Question 20

14. With a loss of combined hydraulic fluid, what is the primary reason that the
    aux hydraulic pump is selected ON prior to landing?

Answer 20

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

Question 21

15. What action is required if a red “REV UNLOCK” CAS message illuminates in
    flight?

Answer 21

Reduce power on the affected engine and select the emergency stow switch
to STOW
Maintain a maximum airspeed of 200 KCAS

Question 22

16. How is the auxiliary hydraulic pump powered?

Answer 22

By using DC power through the battery tie bus

Question 23

17. How can the utility hydraulic system be actuated?

Answer 23

Manually by the pilot

Automatically in the event of a combined hydraulic failure