Ok, this has happened to me twice now.  I get my P3P out about 1800 to 2000 ft and the controller and video lose signal completely!! The app says "Disconnected" and the controller starts beeping and flashing red.  What do you do in this situation??  Reboot the app?  Power cycle the controller? Both?  I mean, the Phantom came home both times without a hitch, and once it got within a few hundred feet, I could control it even though the controller was still beeping and flashing red.  Thank God I had it set to "RTH" when it loses signal (why anyone would set it to anything else is beyond me) but is there a "protocol" for this to regain full control?

ur p3 will fly back home, make sure uve selected the correct height. once bird is back within range  the rc will reconnect and the device(maybe the device). at that point once u see the p3 u can take over and fly it home and land. then try seeing why the device didnt reconnect(if thats the case)

I would upload your flight logs to HealthyDrones.com and see if you can see anything with the signals.  I know this sounds silly and probably not the case but I hope that in this case your controller antennas were out and not still tucked away. Hate to say it but once I had someone gabbing at me while I was setting up my hood and I got out about 1500 feet when I glanced down and noticed mine were tucked in DAMN, I pulled them out immediately but I still had a good signal.  Now that is added to my checklist.

The antennas were straight out...that was the first thing I looked at when it lost signal...

I haven't tried power cycling the controller, I'd be afraid that I'd lose control completely and not be able to land it.  I tried re-starting the DJI Go app, but it didn't reconnect at all.  I will admit the fog was starting to roll in when it lost control, so it may just be a weather issue.  This has never happened on clear, sunny days...but where I live (San Bruno, CA) there are more foggy days than anything else.  

Where is the setting to set Return to Home upon loss of signal?

in the controller settings, under "Advanced Settings"...I think

Did you fly in the fog?  I can tell you that I was a bit surprised when I brought mine back through fog and it was VERY wet.  Not cool.

SpunOne69 Posted at 2015-8-26 10:14
The antennas were straight out...that was the first thing I looked at when it lost signal...

This has been said at least 100 times already....

Don't just arbitrarily set your antennas flat and then leave them. The antennas work best at right angles to your Phantom. Do not point your antennas at your Phantom - that's the weakest signal point.

Imagine the antennas are mirrors and you want your signal from the Phantom to reflect off the mirror as directly as possible. When you first launch your Phantom and it's directly overhead, antennas straight out is appropriate. When your Phantom gets 1,000 feet away from you and 200' up in the air, readjust your antennas so they are pointing more toward straight up.

Ahhhh...I was doing almost the opposite!!  Thanks for the tip, I'll try that next time

And no, i don't fly it directly in the fog...I usually fly it around my neighborhood when I get home from work (just for fun) and where I live it gets foggy in the afternoons like clockwork. Usually, I bring it home when the fog starts to get heavy.  I did fly it at night in the fog once (I was slightly drunk) and it was a little damp when I brought it back.  I just wiped it down with a dry cloth and it was fine...   The lights did look REALLY cool in the fog, kinda like some UFO...ha ha ha