Hydraulic Flashcards
Hydraulic system provide power for:
- flight controls
- spoilers
- landing gear
- nose wheel steering
- wheel brakes
- thrust reversers
Normal hydraulic pressure
3,000 psig
Hydraulic System 1 is comprised of:
- one reservoir
- one engine driven pump (EDP 1)
- one electric pump
- one accumulator
Hyd system 1 powers
- elevator (left hand outboard)
- rudder (upper)
- thrust reverser (engine 1)
- multi function spoilers (l and r panels 3 and 4)
- ground spoilers (l and r panel 2)
- outboard brakes
- emergency parking brake
What does the hydraulic accumulator do?
helps maintain constant pressure by covering transient demands during normal operation and keeping residual pressure to avoid pump cavitation
Hydraulic System 2 is comprised of:
- one reservoir
- one engine driven pump (EDP 2)
- one electric pump
- one accumulator
- PTU
Hyd system 2 powers
- elevator (left and right inboard)
- ailerons (right and left inboard)
- thrust reverser (engine 2)
- multi function spoilers (l and r panel 5)
- ground spoilers (l and r panel 1)
- inboard brakes
- nose wheel steering
- landing gear
- emergency parking brake
How are the engine driven pumps powered
engine accessory gear box
In flight the electric pump 1 and 2 activates automatically when:
- EDP or engine fail or
- flaps selected greater than 0
- during landing for 60 seconds to avoid abrupt hyd pressure variations in the event of engine failure
On ground the electric pump 1 and 2 activates automatically when:
- flaps greater than 0 and
- thrust levers set to takeoff thrust or
- groundspeed greater than 50 its
- during takeoff w/ thrust levers at TOGA for 60 seconds to avoid abrupt pressure variations in the event of engine failure
On the ground electric pump 2 automatically activates when
- engine 1 running and parking brake released
- engine 1 running and flaps greater than 0
- during engine 1 start if parking brake has been applied at least 6 mins before
What is the purpose of the PTU
assists landing gear retraction or extension should a right engine or EDP pump fail
the PTU is powered by
a hydraulic motor in hydraulic system 1
the PTU will be automatically started when:
- flaps are not set to 0 or landing gear not up
- EDP 1 not failed
- hydraulic reservoir 2 quantity above 12%
(will not activate on ground)
Hydraulic system 3 is comprised of
- one reservoir
- two electric pumps
- one accumulator
Hydraulic system 3 powers
- elevator (right hand outboard)
- rudder (lower)
- ailerons (l and r outboard)
When does hyd pump 3B automatically activate
electric pump 3A failure and position in AUTO
Describe the two emergency valve in hyd system 3
pump unloader valve - The pump unloader valve is used to reduce the discharge pressure of electric hydraulic pump A during its start-up. This will reduce the pump torque and therefore reduce the electrical power required to start the pump.
flow limiter valve - The flow limiter valve is used to reduce the amount of flow provided by electric hydraulic pump A. This will limit the electrical power that the pump can draw and prevent the electric hydraulic pump from stalling the RAT.
HYD 1 or 2 or 3 OVERHEAT warning
associated hydraulic system temp exceeded the caution operational range
HYD 1 or 2 or 3 HI TEMP caution
associated hydraulic system temp exceeded normal range
HYD 1 or 2 or 3 LO PRESS caution
associated hydraulic system pressure is low
HYD PTU FAIL caution
PTU is not supplying hydraulic power to hydraulic system 2, or PTU automatic operation is compromised
HYD 1 or 2 EDP NOT D-PRESS caution
depressurization of the associated engine driven pump has failed
HYD 3 VLV FAIL advisory
one or both hydraulic system 3 valves, used during an electrical emergency, have failed
HYD 1 or 2 EDP FAIL advisory
associated engine driven pump is not providing hydraulic power to the system
HYD 1 or 2 ELEC PUMP FAIL advisory
associated electric pump is not providing hydraulic power to the system
HYD 3 ELEC PUMP A or B FAIL advisory
associated system 3 electric pump is not providing hydraulic power to the system
HYD 1 or 2 or 3 LO QTY advisory
fluid level in the associated reservoir is low
HYD 1 or 2 SOV FAIL advisory
associated SOV is not in commanded position
HYD 3 PUMP A NOT ON advisory
ACMP 3A is not set to ON position
HYD PTU NOT AUTO advisory
PTU is not in auto position
HYD PUMP NOT AUTO advisory
SYS 1 or 2 or 3 electric pump is not in auto position
HYD TEMP SENS FAIL advisory
at least one of the hydraulic temperature sensors are failed and the system is unable to monitor the temperature of that system
HYD 1 or 2 SOV CLOSED STATUS
associated SOV closed
