You do realise this would add so much more required strategy into the game? Fair enough for not agreeing over the X-planes bit, even I didn't think that was the best idea ever. But all the towns, air bases, cities, etc. are all consistent in their layout. These fields would be the one thing that isn't, and would supply strategic value if you use them correctly. They could also be used to spawn supply routes, so these 'invisible fields' would essentially kill three birds with one stone. It would require more supply routes for those who enjoy destroying trains, barges and convoys, it would give those who enjoy reconnaissance missions a go at actually trying to find something, and those who want extra fuel and ammo will have it at their fingertips.