The facts really seem to indicate that a "magic show" is being staged for or by our military. They operate these drones in a manner that leads observers to believe the impossible.
As I've mentioned, I have more flight hours than god himself, and I've never seen one. It's no surprise they concentrate around Navy ships and land based Airframe development centers.
It's utter nonsense to think these things came 4.25 light years, the closest star, Proxima Centauri and simply harass our ships, while ignoring most of the rest of the world. It is a deliberate magic show.
I've seen a daytime meteor and a prototype stealth plane with 2 engines. Nothing else.
ALSO, a very high performance drone evaded and greatly outperformed a law enforcement helicopter around the Southern US border. These things exist and perform remarkably well.
The mystery drone flew up to 14,000 feet and was tracked for over an hour. Now the FBI is investigating.
www.thedrive.com
In my post above, I indicated the type of engines probably used. They are a variation of conventional fuel burning piston engines, with 4 rotors on one engine. They are also very efficient and quiet (requires no muffler). The engines are of specific design, single stroke 2 piston 4 combustion chambers, with end mounted crankshafts. This is not vaporware, they had a display at Sun N Fun. Very impressive stuff, with engines ranging from 15HP well in to the hundreds.