This can be done as is....
I'm not saying I can do it every time, but it can be done.
Think of you PageUp/PageDown as your collective.
Come in low and fast (watch out for that tree
)
press Page down and pull back then tap page up reallll quick you'll need to tap between them (PU and PD) but looks awsome when you get it right.
Tried it in "the Mog" island map in both a little bird and a ADF Blackhawk with good success rate.
Now if you're talking an AI doing it? That's just too painful to contemplate. I would imagine some serious work from an AI script but then again these scripting guys blow me away with their skills ;D