The owner of the DJI Phantom 4 that collided Sept. 21 with a U.S. Army UH–60M Black Hawk helicopter that was on security patrol over New York Harbor told federal investigators he had lost sight of his quadcopter minutes before the collision, had attempted to activate the automatic return-to-home function without success, and was surprised to learn it had collided with the helicopter more than two miles away.
Source: aopaDrone far beyond sight during Black Hawk collision