Just flying along,and disconnected came up. 13 sat's HP was set failsafe was set. Hit RTH and waited Thats was a LONG wait. while waiting Everyone (but me )was panicking saying what are we going to do? We can go find it. I knew that was not going to happen ,,, past the farm,over the lake and lost it over the cedar swamps. we would be better off finding it in the lake, but if it went down in the cedar swamp (3-400 acre's) ,its gone..it's so tight in there the P3 would be up in the canopy . Well while waiting ,(and figuring out where I'll order another from ) I restarted pilot app, Still nothing. Then restarted the controller (trying to remember if that was a good move or would it fall to the swamp) as soon as it started back up I had Video and saw it was in RTH mode. Took back control ,and headed home I dont know why it happened 60hours without a problem 1.1,9, Firmware Hope for the best , expect the worst.