Colonel William T. Coleman is a retired Air Force bomber pilot, former Public Information Officer for Project Blue Book, and Air Force's Chief Public Relations Officer during the early 1970s. He was also the Producer of a series called "Project UFO" that ran on NBC for two seasons. (1978-79)

In June of 1978, while promoting his new TV show on the Merv Griffin show, Coleman spoke about a UFO sighting he had experienced while a bomber pilot in the fifties.

"We were cruising at 10,000 feet when we spotted a target somewhere around 20,000 to 25,000 feet. It was about seven miles in front of us to our right, and we were overtaking it. It then started descending across our flight path, and I decided to check it out. So I advanced power and began closing a little faster and descending. We kept getting closer and closer and pretty soon we were within a mile of the object, flying over trees at 345 MPH."

(The plane closed to within an eighth of a mile of the disc-shaped object.) "It was about 60 feet in diameter and 10 or 11 feet thick through the center," he said. "It had what looked like a titanium-type finish (silver gray). I pulled up and made a hard turn that put it out of sight for roughly four seconds. We whipped back to pull up alongside of it and it wasn’t there. I zoomed up to 1500 feet. `There it is!' I said. It was about 2 miles in front of us going across a field leaving a dusty trail behind it. I guessed its speed at about 170 MPH." After another dive, the crew lost sight of the object. "We never saw it again."

 

Source: http://www.presidentialufo.com/old_site/col__william_coleman.htm