Sorry if I like taking planes out on missions, it's not terribly fun having to fly out to the far side of the map and back constantly. And if you haven't noticed, you don't really need more than a hundred feet to take off with a plane, and as Corrodias pointed out, you start off on pretty tall buildings, giving you plenty of correction time.
Also about police forgiveness, you keep a star if there are cops still shooting at you, making it useless for that purpose. Pretty much, you can't snag a plane if you have more than one star, which is pretty annoying.
EDIT: Okay, it looks like the flag that makes it appear in the helipad is vehicle_type, however I think that same flag has something to do with how the engines work, so changing it from airplane to helicopter is probably fucking something up. I can't actually look at the plane in the helipad garage, the game crashes to desktop.
Anyone know a workaround?