Rockslider has put up another piece on Halo 1; this one covers how to lure Banshees into areas they don't normally belong, and the strange behavior they exhibit once they get there. This piece covers level 2, "Halo".
Quite what the explanation for the weird behaviour is, I don't know. I find the grenade chasing business especially baffling. What on earth is there in the game programming that makes them so interested in grenades in these areas, yet not in the valley? Is it actually some sort of 'Easter egg' somebody sneaked in? Seems doubtful; I'm guessing it's some unintended consequence of the Banshee being in an environment that wasn't planned for. If anyone reading this can shed some light on these behaviours or has a theory, I'd be happy to hear about it!
Having just played the first few levels of the original game this weekend, I also noticed some of the same Banshee behavior, as well as some other, related non-Banshee behavior.
I have a feeling that the scripting for Banshee pilots (or perhaps any AI unit using a vehicle like a Banshee, Wraith, or Shade turret) is "overlaid" on top of that unit's basic AI routines. So the normal Banshee behaviors we're used to seeing, such as the dive-bombing and so on, only exists in environmental areas where Bungie expected Banshees to be, and often times wrote specific scripts for specific areas.
Click 'read more' from the front page for the entire article.