Hydraulic System Flashcards
When will the demand pumps be commanded to operate if the hydraulic demand pump selector is in the auto position?
- when related engine driven pump (edp) output pressure is low
- When related fuel control switch is cutoff
- during periods of higher demand
- if the edp fails
- 1&4 operate when te flaps in transit
What does the hydraulic SYS FAULT light indicate
- low hydraulic pressure
- low reservoir quantity
- excessively high fluid temperature
What does a hydraulic demand pump low PRESS light indicate
- selector is OFF or AUX position
- demand pump is operating but output pressure is low
- demand pump has failed
What does a hydraulic reservoir quantity indication of .8 mean (secondary eicas)
80% fluid service level
What does the magenta FR displayed next to a hydraulic quantity indicator on the secondary Eicas mean?
Reservoir should be serviced (refilled) ground only
LO - displays anytime quantity low
When is the engine driven hydraulic pump pressurized?
EDP switch is ON
and
Associated engine is running
And
Associated engine fire switch is not pulled
Which demand pumps are air driven and which ones are electrically driven?
1&4 air
2&3 electric
What is the purpose of the auxiliary pump?
Elec motor on system 4
Ground handling prior to engine start
Aux pump runs until edp pressurized, does not trip off
Why are the hydraulic reservoirs pressurized by the bleed air system
Prevent pump cavitation
Ensure positive flow during high demand conditions
How does pulling a fire switch affect the hydraulic system?
- Closes hydraulic fluid shutoff valve
- depressurizes EDP
- demand pump operates (in AUTO)
(No sys fault light)
Hydraulic sys 1 major system components
If GE ACARS
If - Inboard Flaps
G - Gear Actuation (body/nose)
E - elevator L
A - Aileron L
C - Center auto pilot
A - Alternate Brakes 1
R - Rudder Top
S - Steering (body/noise)
Hydraulic system 2 major components
EARE STRAY
E - Elevator (L, Inner)
A - Alternate Brakes 2
R - Right Autopilot
E - Elevator Feel
S - Spoilers 2, 3, 10, 11 (mid of outer group)
T - Trim Horizontal Stab
R - Rudder Lower
A - Aileron (L out, R in)
Y - Yaw Damper Lower
Hydraulic system 3 major components
LEE STRAY
L - Left Auto Pilot
E - Elevator Feel
E - Elevator R inner
S - Spoilers 1, 4, 9, 12 (edges of outer group)
T - Trim Horizontal Stab
R - Rudder Top
A - Aileron (R out, L in)
Y - Yaw damper Upper
Hydraulic system 4 major components
Of BAR SEW
Of - Outer Flaps
B - Brakes Normal and Auto
A - Aileron (R outboard and inboard)
R - Rudder Lower
S - Spoilers 5, 6, 7, 8 (two sets inner wing)
E - Elevator R inner and outer
W - Wing Gear Actuation
