allowing the engineer to repair the little bird hellicopter "in flight" seems like its a bit of a "cheat" for a tandem flying the bird, and it gets to be where you can keep hitting it with TOWs but it just wont go down (and hey, hats off to them for great teamwork to keep it up)

but in general, if you hit a vehicle with missiles multiple times, even with repair, it should go down

my suggestion: change its to where to repair the little bird you have to either land it on ground, or hold it statitionary in the air for 5 seconds or something, just so it prevents the hack where they just keep hammering you with the guns and repairing and you cant take it down