I've discovered the other day that there are turret/aimer nodes for the gun on the back of the LAAT (so it's not just a protrusion on the back of the gunship just for show).
These nodes are "rear_gun_1" and "hp_gun_3"
I added another flyer section onto the republic gunship and made the rear gun functional. However, I bumped into a small problem; the gun is backwards (i.e. it points in the opposite direction of where you are aiming).
Anyone got any ideas of how to reverse the way it points so that it points where you aim?