I don't know how, but I know it's possible. This really cool BFV mod, Arsenal, has a map (Operation Bolo), which is 100% air combat (everyone gets a jet, there's no infantry kits, it's all about air fights), and there is only one objective, which is to take the flying flag in the middle of the map. I'm guessing this is the sort of map you want to make?
[youtube]http://www.youtube.com/watch?v=5T60qZz5FKY[/youtube]