The AA fire distances are defined in the ammo cfg under missileLockMaxDistance for example centurion AA system has 12km reach for it's firing range which means if it's placed in middle of Altis map it will cover almost the whole island.

This maybe a realistic setting but for mission where player is able to fly it would be useful to reduce the distance. Especially for CTI missions where player is allowed to fly around. So I suggest there be some multiplier variable that mission or config makers can set to reduce the AA's range.

So that the final reach for AA could be calculated like this:

missileLockMaxDistance * AArangeMultiplier