RAT MAN ON pushbutton
The flight crew may extend the RAT at any time by pressing the RAT MAN ON pb.
Note: The RAT automatically extends, if:
‐ AC NORM buses, and Engines 1 and 4 fail, or
‐ Four engines fail, or
‐ GREEN + BLUE LO LVL + engine burst is detected, or
‐ Four engine-driven pumps' low pressure.
What's the use in the RAT if there is LO LVL in the green sys?
Is there an auxiliary reservoir or something?