In 1911, Nikola Tesla reveled he was working on an anti gravity "flying machine".
"My flying machine will have neither wings nor propellers. You might see it on the ground and you would never guess that it was a flying machine. Yet it will be able to move at will through the air in any direction with perfect safety, at higher speeds than have yet been reached, regardless of weather and oblivious of "holes in the air" or downward currents. It will ascend in such currents if desired. It can remain absolutely stationary in the air, even in a wind, for great length of time. Its lifting power will not depend upon any such delicate devices as the bird has to employ, but upon positive mechanical action." - Nikola Tesla in New York Herald Tribune, Oct. 15, 1911
What happened to this anti-gravity craft of Tesla's?'