What are the three hydraulic systems in the aircraft?

The three hydraulic systems in the A320 aircraft are indeed referred to as Green, Blue, and Yellow. Each of these systems serves specific functions and supports various aircraft systems to ensure safety and efficiency during flight.

The Green system is primarily used for normal operations, including the operation of flight control surfaces and landing gear. It is the main hydraulic system and is powered by engine-driven pumps, providing redundancy and reliability.

The Blue system is typically used for backup functions and is powered by an electric pump that can maintain hydraulic pressure even if the engine-driven pump is not operating. This system also supports critical operations such as the alternate braking system.

The Yellow system is used for additional functions, including the operation of the thrust reverser and some brakes. It can be powered by the APU (Auxiliary Power Unit) in addition to engine-driven pumps, allowing for operational flexibility on the ground.

Understanding these systems and their functions is crucial for pilots and crew members, as they play a vital role in the aircraft's overall performance and safety.