Hydraulic System

Question 1

The Demand Pump Selectors for System 1 and 4 are in AUTO. What will cause them to activate?
(AOM Vol II, Ch 13)

Answer 1

• Respective engine pump output is low.
• Respective Fuel Control Switch is in cutoff .
• Flaps in transit on the ground .
• Flaps out of up in flight.

Question 2

The Auxiliary Hydraulic Pump(s) are powered by what bus or busses?
(AOM Vol II, Ch 13)

Answer 2

• The Ground Handling Bus.

Question 3

The number 4 Auxiliary Hydraulic Pump is selected on. Is the number 4 SYS FAULT light illuminated
(AOM Vol II, Ch 13)

Answer 3

• No.

Question 4

Name the power sources for the Demand pumps?

AOM Vol II, Ch 13

Answer 4

• Number 1 and 4 are air driven.

* Number 2 and 3 are electric.

Question 5

What causes the hydraulic SYS FAULT light to illuminate? (AOM Vol II, Ch 13)

Answer 5

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

Question 6

What is the minimum hydraulic quantity for dispatch?

AOM Vol I, Ch NP

Answer 6

• .70 as indicated on the secondary EICAS HYD synoptic or STAT display.

Question 7

What is the implication of a BRAKE SOURCE light illuminated in flight?
(AOM Vol II, Ch 13)

Answer 7

• You have lost hydraulic systems 4, 1 and 2.

Question 8

Hydraulic System 1 EDP is leaking. The EICAS advisory message “HYD PRESS ENG 1” is displayed. You look on the STATUS Page and see that the system 1 quantity indicates zero. Is Hydraulic System 1 still powered? If so, why?
(AOM Vol II, Ch 13)

Answer 8

• Yes
• The ADP draws its supply from the reservoir bottom. The EDP draws its supply from the reservoir at a level above the bottom, but coincident with the zero index of the quantity indication.

Question 9

Hydraulic System 1 is unpowered. What major components are now unavailable?
(AOM Vol II, Ch 13)

Answer 9

• Nose and Body Gear hydraulic operation.
• Nose and Body Gear steering.
• Inboard Trailing Edge Flap hydraulic operation.
• Autopilot C.
• Left outboard Elevator.
• System 1 Alternate brakes.

Question 10

Why does RF display next to the hydraulic quantity indication?
Where is it displayed?
Will it display in flight?
(AOM Vol II, Ch 13)

Answer 10

• Indicates that refill of the hydraulic reservoir is required.
• It is displayed on the Secondary EICAS Status Page and Hydraulic Synoptic.
• No.