I recently reinstalled SHIII after a long absence. Admittedly I decided to try GWX this go round (I was a dedicated NYGM from the word go). GWX is a great mod, well put together but after sinking an armed trawler with my AA guns (I was just messing around) I decided to go back to NYGM.
Quick observation: I witnessed an air attack on my base as I was leaving and basically submerged so I can watch the carnage unfold using external view in relative safety. I noticed the Heavy Bombers (B-24's), once dropping their bombs, stayed around and strafed targets until all of the targets were gone. I'm actually more of a WWII air war buff than submariner and that behavior is sort of unrealistic. Granted the B-24's would also probably be at 17,000 ft or more but that's a constraint of the sim.
Great mod though. I'm glad to be back so to speak.
edit: I peeked into some of the a/c files and noticed that there are "level bombers" included in the sim. So maybe those were meant for me and not a scripted air attack on the base! I've since tweaked the number of air attacks down a bit so I get (on average) one or two attacks/sighting every few days. With occasional multiple attack/sightings in one day.