CnCGEdit is a piece of ****, so that must be the reason
Seriously though, really, it's horribly limited and it's very well possible that some options are not correct in it.
Landable? I called that option "Airplane Logic" or "airplane special" in UGE (don't remember which), since its effects are vastly more than just allowing a plane to land & take off.
In fact you can turn it back on once you have a savegame where you have your A10s selected and in the air... then they actually act like A10 planes again (and, oddly enough, have infinite ammo).
The only problems are that they only take Attack commands (so you need to use [CTRL]+click to move them around), and if they fly out of the map you can't get them back.
The full lists of edits needed is:
Buildable -> true
Selectable->true
Airplane special ("landable") -> false
This works. Just tested in TibEd.
This post has been edited by Nyerguds: Mar 19 2008, 07:55 AM