Hydrualic System Flashcards
How many hydraulic systems are there?
2, identical but independent
What pressure and rate does each system supply?
1500psi
4GPM
What happens if one system fails?
Second system will completely support all hydraulic demands
How is hydraulic fluid supplied to the SAS extensible links?
SAS control shut off valve
Explain the hydraulic reservoirs
Two tanks. 0.94 capacity per tank Low fluid switch for each tank (approx 1/4 remains) Fill cap and level gage for each tank Pressure relief valve per tank (inside) Serviced with 5606 hydraulic fluid
What type of hydraulic pumps do we have?
Constant pressure variable rate pumps. Will vary flow rate to maintain pressure
What is mounted to the hydraulic pumps?
Seal leakage drain that drips into forward transmission drip pan
Where are they hydraulic pumps mounted?
Bottom of forward transmission
How is hydraulic power provided to the lower dual stick boost actuators?
Stick boost manifolds (2)
How many filters are there in the hydraulic system?
9
4 pressure filters
2 case drain
2 return
1 vent
Where are the case drain and return filters located?
In front of forward transmission.
Return outboard
Case drain inboard
Where are pressure and vent filters located?
2 pressure on aft potion of fwd transmission deck.
2 pressure in SAS closet
1 vent in cockpit behind LH pilots seat
Do pressure filters bypass?
No
When will all filters pop the pressure differential indicator?
60-80PSI
Describe the hydraulic accumulator.
500+/-25 psi nitrogen pre charge
25 square inch floating piston type
Direct reading pressure gauges located in companionway
Absorbs large hydraulic demands in system
How do lower boost actuators work?
Flight control rod moves operating valve. 1500 PSI is directs to proper side of dual pistons. Each hydraulic system provides power to 1 piston.power piston moves and imparts controls movement. Once proper amount of control movement has occurred the operating valve mechanically re-centers.
What happens to the boost actuator if one hydraulic system fails?
Side that’s failed is set to fluid bypass to prevent hydraulic lock. Other power piston functions normally
How are the hydraulic pressure gauges powered?
26VAC 400 HZ
What is a snubber?
Located just prior to hydraulic pressure transmitter, stabilizes pressure reading to the gauges
When do the hydraulic pressure switches activate? What do they do?
1000 psi
HYD BOOST FAIL master caution light
Set opposite SAS to full gain
What is the min/max operating pressure of the hydraulic system?
1050-1750psi
