A321 ferry flight with L/G down: APU ON?
 

Hello everyone! A question for airbus heads :)

Why is there a requirement to keep APU running during the whole flight time with L/G down?

We operate a fleet of A320/321/320N/321N (CFM), but such a requirement applies only to A321 CEO.

I suppose this has something to deal with ELEC EMER and LGCIU proximity sensors, but can’t find anything specific to A321.

Any ideas?

Not on a bus but I did it in the commuters once. Nothing in manual and company could not even give me fuel flow or
any max altitude data. I just topped it off with gas flying over Eastern US states plenty of divert options
The things we used to get away with years ago...Sure now there was something illegal about that operation

Old and knackered A320's drop onto battery power when gear is down in emergency electrical configuration, at which point I'm pretty sure APU start is inhibited (and if not, a terrible idea).