HYDRAULICS Flashcards
What’s the function of the accumulators?
Helps to maintain a constant pressure by covering transient demands during normal operation
When does the RAT extend automatically?
The RAT extends automatically if AC BUS 1 and AC BUS 2 are lost
What’s the normal pressure in the hydraulic system?
3000 psi
What’s the function of the fire shutoff valves in the hydraulic system ?
To shut off hydraulic fluid to the engine driven pumps
Which hydraulic systems have fire shutoff valves?
Green and Yellow systems
How can the crew close the hydraulic fire shutoff valves?
By pushing the ENG 1(2) FIRE PB
How many hydraulic systems does the A320 have and what are their colors?
3 and they are colored GREEN-BLUE-YELLOW
What is the pressure output from the RAT in the hydraulic system?
2500 psi
What happens when the RAT MAN ON switch on the hydraulic overhead panel is pushed?
What doesn’t happen?
It extends the RAT, pressurizes the BLUE system. It does not start the emergency generator
What is the function of the PTU in the hydraulic system?
It’s function is for the YELLOW system to pressurize the GREEN system and vice versa
When you get a “G RSVR OVHT” message, why does the ECAM procedure ask you to switch off the PTU first?
To prevent the PTU from pressurizing the GREEN system
When will the PTU in the hydraulic system start operating?
When the pressure difference between the GREEN and YELLOW system is greater than 500 psi
What is the purpose of the leak measurement valves?
To measure leakage in each circuit
Why are the hydraulic reservoirs pressureized with bleed air?
To prevent cavitation by maintaining a high enough pressure
From where is the bleed air taken that’s used to pressurize the hydraulic reservoirs?
Normally HP bleed air from ENG 1
How many pumps are there that can pressurize the YELLOW hydraulic system?
4
1. Engine driven pump
2. Electrical pump
3. PTU
4. Hand pump
What does the amber level indication mean on the hydraulic quantity indicator?
It’s the warning level
What are the function of the priority valves in the hydraulic system?
To cut off hyraulic power to heavy load users if pressure in a system is low. This is done to maintain pressure to the essential flight controls
What is a LAF in the hydraulic system, and with is it’s function?
Which hydraulic systems has this function?
LAF = Load Alleviation Function Accumulators
It’s function is to maintain operation of ailerons and spoilers during rapid operation in for example turbulence.
GREEN and YELLOW system has this function
Ailerons and spoilers 4+5 deflects upwards to reduce the stress on the wing root
Spoilers augments the ailerons in gusty conditions
Name a few items that is pressurized by the GREEN hydraulic system
NWS
Landing gear
Normal brakes
ENG 1 Reversers
Spoilers 1+5
L elevator
Flaps/slats
Rudder
L/R aileron
Stabilizer
Yaw damp
Name a few items that is pressurized by the BLUE hydraulic system
Emergency generator
Spoiler nr 3
Slats
Rudder
L/R aileron
L/R elevator
Name a few items that is pressurized by the YELLOW hydraulic system
Reverser ENG 2
Flaps
Rudder
Alternate/parking brake
R elevator
Spoilers 2+4
Stabilizer
Yaw damper
What hydraulic system supplies nose wheel steering (NWS)?
YELLOW
With only GREEN hydraulic system pressure, will both flaps and slats operate?
Yes, but at half speed