Hydraulic System pressure
3000 psi
Components of Hydraulic System #1
- 1 x reservoir
- 1 x engine-driven pump
- 1 x electric pump
- 1 x accumulator
Systems on Hydraulic Sys #1
– Elevator (left hand outboard actuators)
– Rudder (upper actuator)
– Thrust reverser (engine 1)
– Spoilers (left and right panels 2, 3 and 4)
– Outboard brake
– Emergency parking brake
Automatic actuation of the hydraulic shutoff valve (SOV)
125ºC
Electric Hydraulic Pump system logic
In Flight activates if:
- EDP or engine failure
- Flaps greater than 0º
On the ground with Flaps greater than 0º and:
- thrust set for takeoff thrust
- ground speed greater than 50 knts
*#2 electric pump will also turn on with ENG 1 running and parking brake released
Components of Hydraulic Sys #2
1 x reservoir 1 x EDP 1 x electric driven pump 1 x accumulator 1 x PTU
Systems on Hydraulic Sys #2
– Elevator (left and right hand INBOARD actuators)
– Ailerons (right and left INBOARD actuators)
– Thrust reverser (engine 2)
– Spoilers (left and right panels 1 and 5)
– Inboard brake
– Nose wheel steering
– Landing gear (retraction and extension)
- Emergency parking brake
Function of PTU (Power Transfer Unit)
- assist in landing gear extension or retracting during ENG 2 or EDP 2 failure
- pump located in HDY Sys #2; motor located in HYD Sys #1
- will not activate on the ground
Systems on Hydraulic Sys #3
– Elevator (right hand outboard actuators)
– Rudder (lower actuator);
– Ailerons (left and right outboard actuators)
Components of Hydraulic Sys #3
1 x reservoir
2 x electric driven pump
1 x accumulator
HYD Sys 3 overheat protection
- Both Electric Hydraulic Pumps (3A and 3B) will automatically be turned OFF at 125ºC
- inhibited during electrical emergency
Why does HYD Sys 3 Elec pump A not have an AUTO position
- Electric Hydraulic Pump 3A (ACMP 3A) is the primary power source for Hyd System 3
- powered by AC ESS BUS
How many applications of the parking brake are provided by the accumulator
- 6 applications or 24 hours
