In the April 7, 1952 article by Robert Ginna, "Have We
Visitors From Space?"
"Nevertheless in serious moments most people were a little worried
by all the 'chromium hubcaps,' 'flying washtubs' and 'whirling
doughnuts' in the sky. Buried in the heap of hysterical reports were
some sobering cases. One was the calamity that befell Air Force Captain
Thomas F. Mantell on Jan. 7, 1948. That afternoon Mantell and two other
F-51 fighter pilots sighted an object that looked like 'an ice-cream
cone topped with red' over Godman Air Force Base and Fort Knox, Ky.
Mantell followed the strange object up to 20,000 feet and disappeared.
Later in the day his body was found in a nearby field, the wreckage of
his plane scattered for a half mile around. It now seems possible that
Mantell was one of the very few sighters who actually were deceived by
a Skyhook balloon, but the incident is still listed as unsolved by the
Air Force files."
When newsmen began asking Ruppelt whether the article was Air Force
inspired, Ruppelt replied that they had furnished Life with some raw
data. "My answer was purposely weasel worded", he said, "because I knew
that the Air Force had unofficially inspired the Life article... [and
also knew that the strongly implied answer that UFOs were
interplanetary] was the personal opinion of several very high-ranking
officers in the Pentagon - so high that their personal opinion was
almost policy." (Ruppelt, p. 132.)