Mantell crash, Godman Field, Kentucky

Capt. Thomas F. Mantell, flying a National Guard P-51, was killed on 7 January 1948 after chasing an object near Godman Field, Fort Knox, Kentucky. The Godman Field incident checklists list the date and place and record about a dozen separate observers' reports under incident 33 and its sub-numbers (incident #33 checklist). The Project Sign progress report indexed the sightings as 33 to 33g, with times from 1320 to 1700 (Project Sign table).

According to the checklist narrative, military police and state police reported a large circular object near Mansville, then Irvington and Owensboro. T/Sgt Quinton Blackwell first sighted it from the tower at about 1345 to 1350 (incident 33 narrative). Col Guy Hix recorded a white, round object at about 1445 that looked like an umbrella and stayed stationary for about 1.5 hours (Hix account). Capt Carter, however, recorded the object's speed as about 360 mph from the flight leader's reports (Carter checklist). Three of four P-51s pursued it. The flight leader reported it as metallic and of tremendous size and said he would abandon the chase at 20,000 feet if no closer (radio account). Carter's note suggested Mantell blacked out or went on, then crashed from lack of oxygen (Carter note).

The tower file also records an astronomer's suggestion that the object was Venus or a comet, which Carter's note said did not seem to tally with what was seen (Duesler summary, Carter note). The 1948 Air Intelligence study said it was presumed the pilot suffered anoxia (Study No. 203). A 1949 copy of the same study repeated that statement (report).

Later sources named a balloon. A 1952 press report quoted Dr. Urner Liddel of the Office of Naval Research as saying Mantell chased a Skyhook-type balloon (FBI clipping). In a 1952 briefing, Capt. Edward Ruppelt said the official report held that Mantell ran out of oxygen. He said the object was probably Venus or a General Mills Skyhook balloon (Ruppelt transcript). A Blue Book file said Air Force conclusions were that Mantell tried to intercept a Skyhook balloon (Blue Book file). A British newspaper piece in the FBI file quoted an unnamed fellow pilot who called the oxygen account a cover-up (FBI clipping).