As for raptors they're just avril fodder... but if you don't have an avril (I ALWAYS pick one up before I go anywhere) then you're in deep doodoo =P
You just need a strong strafe relative to the missiles and you can avoid them indefinitely - and/or you can use the enviroment to get rid of them. They're really only dangerous if you went somewhere and sat still.
Generally I'm no big fan of their air-vehicle handling though. It feeling sluggish is okay, but when a purely action-oriented controls layout comes sluggish like that its just stupid. Give me instruments and sensible controls if I'm already supposed to deal with inertia.
And to whoever had problems with gunning the Hellbender, just hit 1-3 for the different positions in it. Yay.