G550 Hydraulics

Question 1

Display the HYDRAULICS 2/3 Synoptic. What systems can power the following components:

Answer 1

• GEAR – L / PTU / EMERGENCY BOTTLE
• BRAKES – L / PTU / AUX / BRAKE ACCUMULATOR
• FLAPS – L / PTU / AUX
• NOSE STEERING – L / PTU / AUX
• GROUND SPOILERS – L / R
• GROUND SPOILER Pop Up (electro-hydraulic servo valves) – L / PTU / AUX

Question 2

When ARMED, the PTU operates automatically ON when?

Answer 2

L HYD pressure drops below 1500 psi

Question 3

Operation of the PTU assumes loss of the:

Answer 3

Left hydraulic system pressure

Question 4

The motor side of the Power Transfer Unit (PTU) is driven by:

Answer 4

Right hydraulic system pressure

Question 5

When ARMED, the AUX pump comes on automatically when:

Answer 5

• L HYD and PTU pressure is below 1500 psi, and
• Brake pedals depressed 10º (pump locks on)

Question 6

What is the Brake Accumulator pre charge?

Answer 6

1200psi

Question 7

If L HYD SYSTEM fluid is depleted but AUX fluid remains in the L HYD reservoir, what system can provide braking?

Answer 7

AUX Pump

Question 8

What is the GEAR EMERGENCY BLOWDOWN accumulator pressure charge?

Answer 8

3100 psi

Question 9

How do you turn off the L / R Hydraulic system to get zero (0) hydraulic pressure?

Answer 9

Pull L / R Fire handle

Question 10

Pulling the Engine Fire Handle will shut off:

Answer 10

• Fuel
• Hydraulic pressure
• Engine Generator (IDG)

Question 11

What are the fluid quantities of the L / R Hydraulic system reservoirs?

Answer 11

• Left – 4.8 gallons on the Synoptic page
• Right – 1.6 gallons on the Synoptic page

Question 12

What is lost if you lose the Left Hydraulic system?

Answer 12

Left Thrust Reverser

Question 13

If no other means of pressurizing the LEFT HYD system (L HYD pump and PTU inop) are available, the AUX pump can provide hydraulic pressure to operate the following components:

Answer 13

Flaps, Brakes and Nose Wheel Steering

Question 14

Can you change the Yaw Damper from the LEFT to the RIGHT?

Answer 14

• Yes
• Use DISP CONT / SENSORS / BOX FGC 2

Question 15

What is lost if you loose the RIGHT HYDRAULIC SYSTEM pressure?

Answer 15

Right Thrust Reverser

Question 16

What will prevent automatic PTU operation when PTU is ARMED?

Answer 16

• L HYD system fluid quantity less than 1.0 gallons
• R HYD system fluid temperature 104.4ºC or more

Question 17

If the PTU shuts of automatically, can you manually select ON?

Answer 17

• YES
• Push “ON” legend

Question 18

Can you replenish the hydraulic quantity?

Answer 18

• YES
• Hydraulic replenish reservoir in the tail compartment

Question 19

Where do you find Manual Operations for the Main Entrance Door?

Answer 19

• AOM Chapter 9 (09-03-20: Manually Opening and Closing Main Entrance Door)

Question 20

How is the auto turn-on feature of the AUX pump checked during PRE-FLIGHT?

Answer 20

• ARM the AUX pump on the overhead panel
• Depress brake pedals more than 10º

Question 21

In the above scenario how is the AUX pump turned OFF?

Answer 21

Select AUX pump ARM / NOT ARM switch to NOT ARM and back to ARM

Question 22

If the PTU is operating automatically, how do stop the operation?

Answer 22

Select PTU ARM / NOT ARM switch to NOT ARM

Question 23

The Landing Gear Emergency Bottle during pre-flight shows 1800psi, the bottle should be serviced at:

Answer 23

3100psi at 70ºF (21ºC)