Generals providing bonus to aircraft

One guy in the steam suddenly asked me if I could create mod which makes Great Generals providing combat bonus to aircraft, if they are stationed in the same city.

I must admit, I love this idea. But... Is it possible to do? To be honest I am sure I have no abilities to do that, but maybe some DLL/lua master will be interested in this concept?

What? You mean you can't do it with a dummy building

Its an OnUnitSetXY event handler. If unit being moved is a GG, loop all units for the owner of the GG, if the unit is an aircraft, give/remove a special promotion if there is/isn't a GG in the aircraft's base tile.

BUT. The AI would have no knowledge of this so without some extra logic to say "move a GG if one is near into the city before the planes attack" it would effectivly be a "player only" bonus.