Apu shutdown batteries A320

[Speedwinner]

Hello,

Need some help in that: shutting the 320 down. We have external power on, apu was in use and just switched off. The available sign is still on. When i now switch of the batteries with the available light still on will the apu flap still close and do I have still fire protection or is it just only in case I don't have external power on the ship?

Thanks!

[dream747]

I started a thread on this recently and I think we still don't have a sure answer to that!

[vilas]

Speedwinner
Since APU is permitted to be started with batteries alone without external that should answer the fire protection part. APU flap is controlled by APU master so with batteries off and ext.connected flap will close. During start with batteries off the flap will open but APU will not sart and auto shut down. However different MSNs have different APUs you can read my answer on dream747's thread.

[Speedwinner]

Thanks man !