Hydraulic Flashcards
All the hydraulics operate at a normal pressure of?
3,000psi
The hydraulic power is provided by?
Three independent systems.
Numbered 1,2,3
3 being the biggest and 1 being the smallest.
Each system has how many pumps?
2
Main pump A (engine driven)
Backup pump B (AC motor pumps ACMP)
When pumps are in AUTO MODE, what does that mean?
Pumps will operate when their respective buses are powered, any generator operating, and flaps out of zero.
Reservoirs and accumulators
Each system is a sealed storage tank filled via ground service
panel located directly below the hydraulic equipment rack.
Fluid is delivered under pressure to the EDPs and ACMPs
One accumulator per system stores hydraulic pressure.
Gas charged with dry nitrogen.
Systems 1&2 cooling?
Cooled by a common air/oil heat exchanger located in aft
equipment bay
Air from ram air scoop directed across heat exchanger
On the ground an electric fan inside the heat exchanger
draws air from ram scoop for cooling
Hydraulic shutoff valves?
Electrically operated HYD SOVs installed in supply lines
between reservoir and EDPs.
To interrupt the flow of fluid to the EDP.
Valve position shown on HYDRAULIC synoptic page.
Normally open.
Press the HYD SOV or ENG FIRE PUSH switchlight to close
Why would you close the HYD SOV.
If the hydraulic fluid is overheating?
Pump 3A normally runs continuously with the switch in the ON position.
True
3B in auto mode will?
3B pump will operate when the respective bus is powered,
any generator is operating, and flaps out of zero.
3B is automatically powered by what during complete AC failure?
ADG
System 3 cooling?
Components are not in close proximity to any appreciable
heat sources (engines) and relies on natural convection and
radiation to dissipate heat.
Does not use a heat exchanger.
Low pressure caution for hydraulics?
1800psi
High pressure caution for hydraulics are?
3200psi
Pressure relief for hydraulics?
3750psi
