Hydraulics Flashcards
How many hydraulic systems does the A320 have and what are they?
- 3 systems
- green blue and yellow
What is the hydraulic system pressure?
3000 psi
How is normal hydraulic pressure produced
Engine driven hydraulic pumps
How can back up hydraulic pressure be produced?
- electrically driven hydraulic pressure pumps (Y/B only)
- Power transfer unit (PTU) (G/Y only)
- ram at turbine (RAT) (blue)
- hand pump (yellow)
How many accumulators are installed and what are they used for?
- 3 accumulators one for each hydraulic system
- They help maintain a constant pressure during transient demands
How many engine driven hydraulic pumps are there?
- 2
- One for the green hydraulic system
- One for the yellow hydraulic system
How many electric driven hydraulic pumps are there?
- 2
- One for the blue hydraulic
- One for the yellow hydraulic system
The flaps are controlled by which hydraulic system?
Yellow and green
Nosewheel steering and landing gear are controlled by which hydraulic system
Green
The slats are controlled by which hydraulic system?
Blue and green
The parking brake is controlled by which hydraulic system?
Yellow 
The cargo doors are controlled by which hydraulic system?
Yellow
The emergency generator is powered by which hydraulic system?
Blue
How is the blue hydraulic system pressurized?
Single electric pump when engine is running
If the blue hydraulic electric pump fails, how can the blue hydraulic system be pressurized?
Via the ram air turbine (RAT)
Why are the hydraulic reservoirs pressurized?
To prevent pump cavitation
If the yellow engine driven pump fails, what happens to the electric pump
It does not automatically activate. Pilots need to push the yellow electric pump on.
When does the yellow electric pump automatically operate?
When the cargo doors are operated
When does the blue electric pump operate?
- with AC power available
- On the ground with one engine running
- Continuously, in-flight, even if both engines are shut down
When does the PTU activate?
Automatically, if a pressure difference of more than 500 psi exists between G and Y hydraulic systems.
Does the PTU transfer hydraulic fluid?
No, it only transfers pressure but not hydraulic fluid
When does the RAT automatically deploy?
- when AC buses 1 and 2 fail
Which systems does the RAT pressurize?
- Blue hydraulic system
- Emergency generator
If you press the RAT MAN ON pb on the hydraulic overhead panel what happens?
- RAT deploys
- B hydraulic system is powered
- The emergency generator is not powered
If the MAN ON pb on the EMER ELEC PWR panel is pushed what happens?
- RAT deploys
- B hydraulic system is pressurized
- Emergency generator is powered
