I try not to fly over peoples heads, this view came from an area with closed offices & never encroached over the stadium or a heavily populated area
When you lose signal, just as they do on all radio-controlled devices, and your device plummets earthwards, try telling the bloke at number 1 Golf Road that he's not in a heavily populated area as he picks the roof slates up in his back garden, whilst you do a runner.
As long as these things are legal they should legalise the use of shotguns in public places.
When signal is lost, The phantom's have a built in Return to home function, provided this was set up at the take off point, which I always do pre flight.
I have tested it in a field, simply turn off the remote & after a minute, the phantom realises it's lost Remote control connection & performs the task of returning to where it took off from.
If it's below 60ft, it will rise up to 60ft & fly back at that height, however, it may crash into something on it's way back, so always try to fly higher as if it is higher than 60ft, it stays at that height
on it's way back. So they certainly won't plummet to the ground if signal is lost, if the battery runs out, it lands itself at a controlled speed where it is, but it's best to make sure you have a timer so you know how long is left & give yourself plenty of time to return & not land on something it shouldn't.