Hydraulics Flashcards
Demand pumps come on in AUTO?
- Related ENG Pump output PRESS low
- Related Fuel Control Switch in CUTOFF
- Pumps 1 & 4 also w/flaps in transit/out of UP in FLT
Hydraulic system SYS FAULT light on panel mean?
- LO PRESS
- LO Reservoir
- HI TEMP
If engine driven pumps are operating normally, demand pumps 1 and 4 also operate?
- In transit on ground.
- Flaps out of UP in flight.
Hydraulic demand pump LOW PRESS light indicate?
- Selector OFF or AUX
- Output pressure LOW with PUMP ON
- Pump failure
When is ENG driven HYD pump pressurized?
- ENG running
- ENG Pump Switch ON
Which HYD demand pumps are air driven?
SYS 1 & 4 through respective L/R bleed air manifold. Air sources include Engine Bleed Air and APU Bleed Air.
Purpose of HYD AUX pump?
Used for ground ops until engine pump pressurizes.
- Example: Wheel Braking for towing.
Why are HYD reservoirs pressurized w/bleed air?
- Prevent pump cavitation
- Ensure positive flow during HI demand conditions
How does pulling FIRE Switch affect HYD SYS?
- EDHP SOV closes
- EDHP Depressurizes
- Related demand pump operates
Which HYD systems provide redundant power to primary flight controls?
SYS 1 and 4
HYD systems power primary flight controls?
SYS 2 and 3
HYD systems for upper/lower YD?
Upper - HYD SYS 3
Lower - HYD SYS 2
HYD system for stab trim and elevator feel?
HYD SYS 2 and 3
Which HYD systems power AP servos L, C, and R?
L = HYD SYS 3 C = HYD SYS 1 R = HYD SYS 2
Which HYD systems power the spoilers?
HYD SYS 2,3, and 4
Gear retraction HYD systems (numbered)?
1
4 | | 4
1
Speedbrake/Spoiler HYD systems (numbered)?
3-2-2-3 4-4 | | 4-4 3-2-2-3
Trailing Edge Flaps HYD systems (numbered)?
4-1 | | 1-4
PRESS amber light on engine pump switch?
Low engine HYD pump pressure
What happens when Demand Pump selector is placed in AUX position?
Pressurizes SYS 4 on the ground if GROUND HANDLING BUS is powered.
Aileron HYD SYS (numbered)?
(1/2)(1/3) | | (4/2)(4/3)
Nosewheel and Body Wheel Steer HYD SYS?
HYD SYS 1
Wheel Brakes HYD SYS?
NORM - SYS 4
ALT - SYS 1
ALT - SYS 2
Elevator HYD SYS (numbered)?
(1)(1/2) | | (3/4)(4)
Upper Rudder HYD SYS (numbered)?
1
3
3
Lower Rudder HYD SYS (numbered)?
2
4
What 4 monitors are observed when HYD SYS 4 - AUX ON?
- SYS FAULT Light OFF
- PRESS Light ON
- BRAKE SOURCE Light OFF
- ACCUMULATOR PRESS in GREEN band
BRAKE ACCUMULATOR HYD SYS?
HYD SYS 4
When will AUX Pump #4 stop its operation with the switch in the AUX position?
When the #4 EDHP is pressurized.
- EICAS: HYD PRESS DEM 4 displayed
