Hydraulics ***

Question 1

When will the demand pumps operate if the hydraulic demand pump selector is
in the AUTO position?

Answer 1

• EDP pump output pressure is low
• Fuel control switch is in CUTOFF
• Demand pumps 1 & 4 also operate when flaps are in transit, or flaps extended past 1

Question 2

What does the hydraulic system (SYS FAULT) fault light indicate?

Answer 2

• Low hydraulic system pressure
• Low hydraulic reservoir quantity
• Excessive hydraulic fluid temperature

Question 3

What does a hydraulic demand pump low PRESS light indicate?

Answer 3

• Demand pump selector positioned to OFF or AUX

* Demand pump commanded to operate and output pressure is low

Question 4

What does a hydraulic reservoir quantity indication of .80 mean, as displayed on
the Secondary EICAS display?

Answer 4

• 80% of normal service level

Question 5

What does a magenta “RF” displayed next to a hydraulic quantity indicator on
the Secondary EICAS mean?

Answer 5

• The reservoir requires refill

Question 6

When is the engine driven hydraulic pump pressurized?

Answer 6

• The engine is running

* The engine pump switch is ON

Question 7

Which demand pumps are air driven, and which ones are electric motor driven?

Answer 7

• Systems 1 and 4 are air driven pumps, through the bleed air manifold.
• Systems 2 and 3 are electric driven pumps.

Question 8

What is the purpose of the auxiliary pump?

Answer 8

• Used for ground handling operations

• Example: Wheel Braking for towing.

Question 9

Why are the hydraulic reservoirs pressurized by the bleed air system?

Answer 9

• To prevent pump cavitation

* To ensure positive flow during high demand conditions

Question 10

If engine-driven pumps are operating normally, demand pumps 1 and 4 also operate?

Answer 10

• when flas are In transit on the ground.

- Flaps out of 1 in flight.

Question 11

How does pulling FIRE Switch affect HYD SYS?

Answer 11

• EDP SOV closes
• EDP Depressurizes
• Related demand pump operates

Question 12

Which HYD systems provide redundant power to primary flight controls?

Answer 12

SYS 1 and 4

Question 13

HYD systems power primary flight controls?

Answer 13

SYS 2 and 3

Question 14

HYD systems for upper/lower YD?

Answer 14

Upper - HYD SYS 3
Lower - HYD SYS 2

Question 15

HYD system for stab trim and elevator feel?

Answer 15

HYD SYS 2 and 3

Question 16

Which HYD systems power AP servos L, C, and R?

Answer 16

L = HYD SYS 3
C = HYD SYS 1
R = HYD SYS 2

Question 17

Which HYD systems power the spoilers?

Answer 17

HYD SYS 2,3, and 4

Question 18

Gear retraction HYD systems (numbered)?

Answer 18

1
4 | | 4
1

Question 19

Speedbrake/Spoiler HYD systems (numbered)?

Answer 19

3-2-2-3 4-4 | | 4-4 3-2-2-3

Question 20

Trailing Edge Flaps HYD systems (numbered)?

Answer 20

4-1 | | 1-4

Question 21

PRESS amber light on engine pump switch?

Answer 21

Low engine HYD pump pressure

Question 22

What happens when Demand Pump selector is placed in AUX position?

Answer 22

Pressurizes SYS 4 on the ground if GROUND HANDLING BUS is powered.

Question 23

Aileron HYD SYS (numbered)?

Answer 23

(1/2)(1/3) | | (4/2)(4/3)

Question 24

Nosewheel and Body Wheel Steer HYD SYS?

Answer 24

HYD SYS 1

Question 25

Wheel Brakes HYD SYS?

Answer 25

NORM - SYS 4 Auto brake / anti-skid ALT - SYS 1. No Autobarke / anti-skid ALT - SYS 2. No Autobarke / anti-skid Altérnate with Anti-Skid only lateral pairs of brakes front or back pair on each truck

Question 26

Elevator HYD SYS (numbered)?

Answer 26

(1)_(1/2) | | (3/4)_(4)

Question 27

Upper Rudder HYD SYS (numbered)?

Answer 27

1 | 3

Question 28

Lower Rudder HYD SYS (numbered)?

Answer 28

2 4

Question 29

What 4 monitors are observed when HYD SYS 4 - AUX ON?

Answer 29

- SYS FAULT Light OFF - PRESS Light ON - BRAKE SOURCE Light OFF - ACCUMULATOR PRESS in GREEN band

Question 30

What HYD SYS pressurized the BRAKE ACCUMULATOR?

Answer 30

HYD SYS 4

Question 31

When will AUX Pump #4 stop its operation with the switch in the AUX position?

Answer 31

When the #4 EDHP is pressurized. * EICAS: HYD PRESS DEM 4 displayed

Question 32

With the loss of hydraulic system 4 how do I lower the landing gear and flaps?

Answer 32

The Landing gear will have to be lowered using the Alternate Gear Extension switch. The flaps will revert to Secondary mode and extend more slowly.

Question 33

What may cause the nose to pitch up on landing with the loss of hydraulic system 4?

Answer 33

Rapid extension of the Spoilers.

Question 34

What are some examples of major system components powered by each hydraulic system 1 and 4

Answer 34

• Systems 1 and 4 power the steering body gear normal brakes (SYS 4), alternate brakes (SYS 1), trailing edge flaps Systems 1 and 4 also provide redundant power to the primary flight controls.

Question 35

What are some examples of major system components powered by each hydraulic system 2 and 3

Answer 35

• Systems 2 and 3 power the primary flight controls stabilizer trim elevator feel. System 2 also powers the alternate brakes lower yaw damper. System 3 powers the upper yaw damper.

Question 36

What are some examples of major system components powered by each hydraulic system 1, 2 and 3

Answer 36

• Systems 1, 2, and 3 power the respective center, right, and left autopilot servos (L,C,R are powered by systems 3,1,2 respectively)

Question 37

What are some examples of major system components powered by each hydraulic system 2, 3 and 4

Answer 37

• Systems 2, 3, and 4 power the spoilers.

Question 38

What are some examples of major system components powered by each hydraulic system System 1 and 4? Systems 2 and 3? Systems 1, 2, and 3? Systems 2, 3 and 4?

Answer 38

• Systems 1 and 4 power the trailing edge flaps, body gear, normal brakes (SYS 4), alternate brakes (SYS 1), and steering. Systems 1 and 4 also provide redundant power to the primary flight controls. • Systems 2 and 3 power the primary flight controls, stabilizer trim, and elevator feel. System 2 also powers the alternate brakes and lower yaw damper. System 3 powers the upper yaw damper. • Systems 1, 2, and 3 power the respective center, right, and left autopilot servos (L,C,R are powered by systems 3,1,2 respectively) • Systems 2, 3, and 4 power the spoilers.