<snip>
We are just talking about TT anyway, so why would a plane need to fly within range of a Tank?
I think because of the very same reason tanks 'need' to get close to the runway of an airfield 
And as much as I hate it being bombed in TT: -1 on the wish. You might better ask for a separate GV arena if you want a sanctuary. The MA is about the interaction of all kind of combat, even though everyone of us may dislike some of the symptoms and results of it. 
We're talking about Tank Town here, not the general MA. Inherent in the concept of TT is that aircraft will be absent or at least restricted; otherwise any part of the map could serve. Again, in TT, since airfields are generally absent, tanks won't "...'need' to get close to the runway of an airfield...".
MH