How many hydraulic systems are on the airplane ?
What are the main components of the hydraulic system?
- 2 systems.
- Each has an accumulator, two pumps and a reservoir.
- One engine driven the other electric.
What is the pressure on the engine driven pumps?
Electric pumps? any difference in volume?
- 3000 psi
- 2900 psi
- Yes electric pump puts out less volume
What is the purpose of the Hydraulic resevoir?
How many liters are held in the reservoir?
When is a low quantity signaled?
- Self pressurized to avoid cavitation.
- 6 liters
- < 1liter
How does the hydraulic shut off valve close?
Where is it installed?
Can the Engine Driven pump be turned off?
- By pressing the hydraulic ENG pump shutoff. By pulling the fire extinguishing handle.
- Between the reservoir and the engine driven pump.
What are the hydraulic engine driven pumps driven by?
The accessory gear box.
What side is the priority valve located and what is its purpose?
- Only on #1 engine.
- Used to give the flight controls priority if pressure drops below 2600 psi and landing gear is commanded to retract.
What is the purpose of the accumulator on the #1 system? #2 system?
- Keep surges of the hydraulic system to a minimum.
- Assists in raising gear if pressure drops below 2600psi with priority valve. Also let's four cycles of the main cabin door.
- #2 six applications of emergency brake, will hold for 24 hours.
When do electric pumps come on?
- In AUTO MODE:
- N2 is below 56.4% or
- Hydraulic pressure <1600 psi="" br="">In ON mode: selected above.
What are each hydraulic pump powered by?
Powered by opposite DC bus.
What is on hydraulic system 1? 2?
- Ailerons, rudder, outboard brakes, inboard spoilers, thrust reversers 1, landing gear, nose wheel steering, main door.
- Ailerons, rudder, inboard brakes, outboard spoilers, thrust reversers 2, emergency brake.
How is the airstair main door operated?
- raised by two hydraulic door actuators.
- hydraulic system 1
Where is the accumulator located for number one system?
front right side.
Why do we have four gear pins?
for each landing gear and on for the hydraulics.