If a player brings a unit to a location, how do i make it so it kills every air unit and only the air units? This is for an rp map.

Change the elevation flags for the location and uncheck low, medium, and high ground and create the kill trigger for that location.

You can also have it kill specific units, air units, that would be in the location.

While you may think low/med/high air is based on who's on top, it's actually based on the terrain, so keep that in mind. There's low/med/high terrain in just about every map, so you just have to take a look at the tile heights in the wiki, but if you just want air, it's easier to just use all 3.