HYDRAULICS

Question 1

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

Answer 1

•Low hydraulic system pressure
•Low hydraulic reservoir quantity
•Excessive hydraulic fluid temperature
(Two LOWS and a HIGH)

FCOM, VOL 2 13.10.2

Question 2

What does a hydraulic demand pump low PRESS light indicate?

Answer 2

•Demand pump selector positioned to OFF or AUX
•Demand pump operates and output pressure is low

FCOM, VOL 2; 13.10.2

Question 3

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

Answer 3

•Demand pumps operate when respective engine pump output pressure is low,
or when respective fuel control switch is in CUTOFF.
•Demand pumps 1&4 when trailing edge flaps are in transiton the ground
or continuously when flaps extended past 1 in flight.

FCOM 2; 13.10.2

Question 4

On GE -400 aircraft, which demand pumps are air driven, and which ones are
electric motor driven?

Answer 4

•Systems 1 and 4 are air driven pumps.
•Systems 2 and 3 are electric driven pumps.

FCOM 2; 13.20.1

Question 5

On N480MC/N445/446MC which demand pumps are air driven,
and which ones are electric motor driven?

Answer 5

•There are no electric driven demand pumps. Systems 1, 2, 3, and 4
are pneumatic air driven demand pumps

FCOM 2; 13.20.1

Question 6

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

Answer 6

The reservoir requires refill (only displays on ground)

FCOM 2; 13.10.3

Question 7

What is the purpose of the auxiliary pump?

Answer 7

Used for ground handling operations

FCOM 2; 13.20.2

Question 8

When is the engine driven hydraulic pump pressurized?

Answer 8

•The engine is running
•The engine pump switch is ON

FCOM 2; 13.20.1

Question 9

What does a hydraulic reservoir quantity indication of 0.95 mean,
as displayed on the Secondary EICAS display?

Answer 9

Percentage of normal service level (1.00)

FCOM 2; 13.10.3

Question 10

What degraded or inoperative systems can you expect from a loss of hydraulic system 1?

Answer 10

• Centre autopilot
• left outboard elevator
• inboard training edge flap hydraulic operation
• Nose and body gear extension/retaction
• Nose and body gear steering
• System 1 alt bake source

QRH 13.15 & FCOM VOL 2 13.20.3

Question 11

What degraded or inoperative systems can you expect from a loss of hydraulic system 4?

Answer 11

• Right outboard elevator
• Outboard trailing edge flat hydraulic operation
• Two inboard spoiler panels on each wing
• Wing gear hydraulic extension and retraction
• System 4 normal brake system
• Auto brakes

QRH 13.17 & FCOM 2 13.20.3