WHAT WAS THE PHOTO SHOWN TO KANSAS AIRMEN IN MARCH 1966?

Three airman from Forbes AFB in Topeka, Kansas reported seeing an intriguing object in late March 1966. 

They described it as "umbrella shaped", the size of a "B-53 flying flight level 350", it was "white", and had a tail equal to the wingspan.  When first seen it was 45 degrees to 60 degrees above horizon and 45" to 120 azimuth, it moved horizontally at a fast rate, it did a figure eight pattern, hovered, and then , vertically, went out of sight. They viewed the object for 12 minutes.

There were other sightings mentioned for the same time period but what was interesting was the statement made on one document, "after viewing an enlarged photograph of the object all agreed it looked like object they had observed."

There is mention two of a negative or photograph, but a dismissal of the quality of said negative or photograph. No negative or photograph copy is in the file. 

Most logically, this was probably a military craft; since it hovered it may have been a helicopter innovation.  Yet, helicopters have since their introduction remained basically the same. 

What,exactly, was the photograph shown these witnesses?