Clarification of Anti Aircraft Defense

[canuckgamer]

If the AA defense of a fortification is upgraded I assume it benefits a unit in that fortification when attacked by an air unit. However if the AA defense of a city or port is upgraded I assume it only benefits the city or port when it is bombed by an air unit. Or does it also benefit a ground unit in that city or port when attacked by air?

[canuckgamer]

Just to add to this subject, I build a 10 factor AA unit with the Brits to garrison Gibraltar. Since the only way you can take a one hex fortress like Gibraltar and Malta is by relentless air attacks my reasoning is that an AA unit is better defensively against the air attacks compared to a infantry corps or division. I'm wondering what other players use to garrison Gibraltar?

[BillRunacre]

Hi

AA upgrades to the resource will also help protect any units in them from air attack, so it is worth doing.