Lusche is correct. Landing your "GV" is a guessing game if your NOT at your own field. If there are enemy near you (a magical distance but most likely icon range), either on the ground or in the air, then you must land on your own field's road or concrete to be "successful". If there are no enemy in icon range you can land anywhere you want. I've landed in the woods, at an nme hanger, stuck in water, pretty much anywhere as long as it is clear.
The last patch fixed it so that you can land on your own roads as well as concrete making your landing spots more readily available.
Subject to review but that's the best I know of.