The US military was testing and flying UFO design aircraft in the 40's and 50's. They had as many as 35 saucer projects with vertical lift off and descent. The most highly classified was known by code name Silverbug.
Near the end of WWII the allied forces had gained superiorty over the Germans. Or so it seemed. The Germans were looking for a superior craft. The SSE and Vril societies were building craft that looked like UFO's and were capable of vertical take-off's and landings because most of their runways had been destroyed.
The project was headed by Dr. Richard Mehta, sometimes known as the 'Father of Saucerology'. He was hired by the German air force to build a saucer shaped craft that could vertically ascend and shoot down allied planes with rockets. Allegedly the war ended before Metha developed his ship.
The American government recruited some of the German scientists after the war to go to Canada and continue their work. Dr. Metha was one of these men. He work on a secret aircraft project at AVROW Aeronautics in Canada. These were saucer type flying machines.
These saucers were designed to 2300 miles per hour at an altitude of 80,000 feet. Though designed in 1955 the papers describing these design were not declassified until 1995. For over 40 year America's #1 top flying saucer project was top secret.
In the 1950's in Canada Avro revealed the Avrocar to the public. ...snip...
The prototype was placed in a military museum at Fort Eustis, Virginia. One view was that the failed project was simply window-dressing to cover tests of a captured alien flying disc.
More:
http://www.voicenet.com/~wbacon/documents/silverbug.htmlhttp://www.burlingtonnews.net/silverbug.html