Hydraulics

Question 1

Which of the following is not controlled by hydraulics?

Answer what is controlled by hydraulics

Answer 1

Flight controls (elevators, rudder, spoilers, and flaps)
Landing gear operation
Nose wheel steering
Brake systems

Question 2

What is the nominal pressure created by the engine-driven hydraulic pumps?

Answer 2

3,000 PSI

Question 3

What provides back-up pressure for the #1 hydraulic system?

Answer 3

An electrically driven standby hydraulic pump (115VAC)

Question 4

What is controlled by the #1 Hydraulic System?

Answer 4

Brakes (main wheel brakes)
Anti skid
Rudder (lower PCU)
Flaps*
PTU (Power Transfer Unit)*
Inboard Roll Spoilers
Elevators (outboard PCU)

• = priority valve shut off pressure if necessary

Question 5

Which of the following is controlled by the #2 hydraulic system?

Answer 5

Landing Gear
Outboard roll spoilers
Steering of nose wheel
Emergency/parking brakes
Rudder (upper PCU)
Elevator (center PCU)

Question 6

A minimum of _____% must be present in the #1 and #2 hydraulic systems for aircraft dispatch.

Answer 6

40

Question 7

A minimum quantity of _____% must be present in the #3 hydraulic system for aircraft dispatch.

Answer 7

45

Question 8

T/F: The #1 Hydraulic System can be powered by AC ground power and the Standby Hydraulic Pump when the engines are shut down.

Answer 8

TRUE

Question 9

T/F: Both main hydraulic systems control fuel/oil heat exchangers in the associated fuel tank to help cool the hydraulic fluid.

Answer 9

TRUE

Question 10

T/F: The PTU can be turned on automatically or manually for the hydraulic systems.

Answer 10

TRUE

Question 11

How many volts minimum are needed to run the DC motor pump for the #3 Hydraulic System?

Answer 11

24VDC

Question 12

When running on the DC motor pump, what does the #3 hydraulic system get pressurized at?

Answer 12

2,600-3,250 PSI

Question 13

When does the #3 HYD PUMP caution light illuminate?

Answer 13

#3 system pressure falls to 900 PSI
or
Pump has been running longer than 60 seconds on the ground

Question 14

The auxiliary hydraulic system provides power for _____.

Answer 14

Emergency landing gear extension

Question 15

Nose wheel steering is provided by which hydraulic system?

Answer 15

2 system

Question 16

At 2,100 PSI, the priority valve closes in the #1 system, shutting off pressure to the _____.

Answer 16

Flaps and PTU

Question 17

Normal hydraulic pressure from the engine driven hydraulic pump is approximately what PSI?

Answer 17

3,000 PSI

Question 18

What does the Power Transfer Unit (PTU) do?

Answer 18

The PTU uses #1 system pressure to pressurize the #2 system

Question 19

T/F: Hydraulic system pressures and reservoir quantities are normally displayed at the bottom of the first officer’s MFD.

Answer 19

TRUE

Question 20

What electrical source does the standby hydraulic pump need to operate?

Answer 20

115VAC

Question 21

T/F: The standby pump automatically activates when the #1 engine fails during flight.

Answer 21

TRUE

Question 22

T/F: Pilots can manually turn on the standby hydraulic pump.

Answer 22

TRUE