Here is the mod for maximum action and chopper wars. It will give you to max. acess chance to whole maps (for air battle) of Call of Duty: Black Ops- Muliplayer's. Tested up to 12 players (12 choppers). And no expected bugs for player numbers up to 18.
That video shows the distance of map. Map is called Villa in official Black Ops 1 Multiplayer maps.
I will share an article soon about the maneuver keys of chopper.