What does a green AVAIL message on the electrical panel indicate?

A green AVAIL message on the electrical panel signifies that the Ground Power Unit (GPU) is successfully connected and providing the correct voltage and polarity for the aircraft's electrical system. This indicates that the power source is stable and suitable for use, allowing for safe operation of onboard systems while the aircraft is on the ground.

This status is essential for ground operations, as it ensures that the aircraft receives the proper electrical supply. A green indication suggests everything is functioning normally, facilitating pre-flight checks and systems operation without relying on the onboard batteries or main generators, which may not be ideal during these phases.

This indicator plays a crucial observational role for operators, confirming that ground support equipment is performing as expected and that the aircraft is ready for further actions, whether it be maintenance, system tests, or preparing for flight. Other conditions reflecting faults or offline status would not present as a green indicator.