How do Air Units Work?

[ComradeP]

They seem to use the PzC system for availability. The main difference I've seen is that the wider range of possible visibility distances for a scenario increases variability.

I'm not sure if the AA unit formula wasn't updated in the manual or wasn't changed, because if it wasn't changed they're now 4 times less effective than before, so the weaker AA fire compared to PzC is another difference.