Lockheed Martin P-791 Hybrid Aircraft

Do I believe in UFOs? Of course! There are without question unidentified objects in our atmosphere. However it does not naturally follow that just because people see something they can't identify that it must be an interstellar spacecraft. While I don't rule out the possibility we are being visited, I believe that many UFO sightings are actually sightings of advanced developmental aircraft. For example, look at the video of the P-791 and imagine seeing it from a distance. From certain angles it would be easy to interpret it as a saucer-shaped UFO.

A Hybrid Aircraft gets part of it's lift from aerodynamics, and part from lighter-than-air gas such as helium. This extra lift allows short takeoffs and landings, extra range, extra cargo, and extra duration. My favorite government organization, DARPA, originally had plans to build a gigantic hybrid craft called Walrus, but for reasons unknown (to me) it was cancelled. Fortunately that didn't stop Lockheed Martin from testing the concept.