Hydraulics

Question 1

There are 3 separate and independent hydraulic systems. Designated as:

Answer 1

❇️Green
❇️Blue
❇️Yellow

Question 2

What are the power sources of the GREEN hydraulic system?

Answer 2

❇️Green:
▪ Engine-driven pump powered by engine 1 (primary).
▪ Power Transfer Unit (PTU) (alternate).

Question 3

What are the power sources of the BLUE hydraulic system?

Answer 3

❇️Blue:
▪ Electrically powered pump (primary).
▪ Ram Air Turbine (RAT) (alternate).

Question 4

What are the power sources of the YELLOW hydraulic system?

Answer 4

❇️Yellow:
▪ Engine-driven pump powered by engine 2 (primary).
▪ Power Transfer Unit (PTU) (alternate).
▪ Electrically powered pump (alternate).
▪ Hand pump – capable of only providing pressure for cargo door operation (Not displayed on HYD page)

Question 5

Explain the operation of the BLUE ELEC PUMP when its pb is selected AUTO (lights out).
❇️On the ground?
❇️In flight?

Answer 5

❇️On the ground - pump is automatically activated and runs continuously with first engine start.
❇️In-flight - pump operates continuously regardless of engine operation provided AC power is available.

Question 6

❇️How are Fire Shutoff valve indications displayed on the ECAM HYD page?
❇️How are the valves controlled?

Answer 6

❇️Green and Yellow system Fire Shut off valves are depicted below the green engine pump depictions.
❇️Controlled by the respective ENG 1(2) FIRE pb.

Question 7

Which pumps are depicted on the ECAM HYD page?

Answer 7

❇️Green Sys ENG 1 PUMP 
❇️Blue Sys ELEC PUMP 
❇️Yellow Sys ENG 2 PUMP 
❇️Yellow Sys ELEC Pump 
❇️PTU (Power Transfer Unit) 
❇️Ram Air Turbine (RAT)

Question 8

What are the indications when the Yellow Electric Pump is selected ON?

Answer 8

▪ ON (white) appears on the YELLOW ELEC PUMP pb.

▪ The triangle on the ECAM HYD page next to the white ELEC indication turns solid green.

Question 9

What is the function of the Power Transfer Unit (PTU) & how does it work?

Answer 9

❇️The PTU is a bidirectional hydraulic motor/pump which provides an alternate power source to either the Green or Yellow hydraulic systems.

NOTE: The PTU transfers power and not fluid between the Green and Yellow systems.

Question 10

What is the indication on the E/WD memo section when the PTU is operating?

Answer 10

▪ HYD PTU appears

Question 11

What conditions will automatically inhibit PTU operation?

Answer 11

❇️When ENG MASTER switches are in opposite positions (one ON the other OFF), and either:
▪ Parking brake is on. or
▪ Nose wheel steering is disconnected by the towing lever on the nose gear. ❇️When the Yellow Electric pump is activated through either cargo door’s operation.

Question 12

What is the meaning of the FAULT light in the PTU pb?

Answer 12

Illuminates as the result of the following within either the Green or Yellow hydraulic system reservoirs:
▪ Hydraulic fluid overheat
▪ Low air pressure
▪ Low hydraulic fluid level

NOTE: The FAULT light does not represent the status or condition of the PTU.

Question 13

What is the function of the RAT MAN ON pb?

Answer 13

❇️Used to manually deploy the Ram Air Turbine (RAT), which provides alternate power to pressurize the Blue hydraulic system.
❇️The emergency generator is not energized with use of this pb.

NOTE: The RAT will not automatically deploy with a failure of the Blue Electric pump.

Question 14

What are the indications when the RAT is deployed?

Answer 14

❇️RAT OUT (green) appears on the E/WD memo section.
❇️The white hollow triangle next to the white RAT indication on the ECAM HYD page turns solid green, and a line connects it to the rest of the Blue system indications .