A320 APU
Hi guys!
I have some questions regarding the A320 APU (131-9A in particular)
If the aircraft is currently powered by the external Ground Power Unit (aircraft batteries not switched on), can I start the APU using only the GPU (without switching on the 2 aircraft batteries)?
If yes, will the APU take over the supply of electricity to the aircraft from the GPU? Or will the GPU remain the primary supplier since the GPU has priority over the APU in supplying the 2 networks (AC BUS1 and AC BUS2)?
Is there any situation where the GPU supplies one AC BUS and the APU supplies the other AC BUS?
Thanks!