I was videotaping UFO Sightings on a regular basis from my back porch in Tilton NH. To practice catching UFOs on film I would often practice on airplanes. One I afternoon I saw a plane doing aerobatics so I filmed it. I did not realize until after I had watched the footage that I had also caught a UFO. The UFO Sighting appears to manifest behind the Plane at the end of a barrel roll and paces the planes speed exactly. This is one of many unexplained objects I have managed to catch on tape. The airport this plane took of from is in Concord New Hampshire almost thirty miles away. This footage is of an AT-6 World War 11 fighter plane and the UFO is what is known as a foo fighter.