i used to remove zzz neighbours
, im not sure now.
I have found this too. If I logged into my support accounts sent planes and then sent F20 after a few days they would be deemed inactive the only way I could then wake them was to login and let it sit for a whilei discovered that if I let the game open long enough, send some planes and visit some friends, it stays "awake". but i'm not sure "how long" is long enough. some 15 minutes seems to be enough to keep them awake, but not enough to get them out of the zzz state, once they fall there