Systems Guide

A318/A319/A320/A321
Professional
SYSTEMS
Systems guide
Vol
4
04-03-50
11 July 2018
The ECAM FUEL page is opened by depressing the ECAM FUEL button. This page is automatically opened if
any of the fuel systems is abnormal.
HYDRAULIC SYSTEM
GENERAL
There are three separate and fully independent hydraulic systems, Green, Blue and Yellow, each with its
own pump(s), reservoir and accumulator. In normal operation the system is fully automated and does not
need any interaction.
• The Green system can be pressurized by an engine-driven pump and can use the Yellow system
via the connection Power Transfer Unit (PTU).
• The Yellow system can be can be pressurized by an engine-driven pump and can use the Green
system via the connecting PTU. Additionally, an electric and a hand pump (not simulated) can be
used.
• The Blue system is powered by an electric pump or the Ram Air Turbine (not simulated) and is
mainly intended as a backup emergency system.
• The Power Transfer Unit is used to transfer pressure between the Green and Yellow systems
when differential pressure exceeds a set limit.