Terre Haute, IndianaOctober 1951

On October 9, 1951, at 1342 (2:42 p.m.), a Chief Aircraft Communicator for the Civil Aeronautics Authority observed a silver, round object pass directly overhead at Hulman Municipal Airport near Terre Haute, Indiana. The witness, described in official reports as "hard headed" and reliable, estimated the object to be about the size of a half-dollar held at arm's length. The object flew in a southeasterly direction, traveling from directly overhead to the horizon in approximately fifteen seconds. The day was clear with bright sunshine and no obstructions to vision. The witness heard no sound and saw no vapor trails, exhaust, or protruding fins on the object.

If the object had been flying at 200 feet altitude, it would have been traveling at roughly 2,880 miles per hour. However, since no exact altitude or distance could be determined, the actual speed remained unknown. The Air Force's own analysis noted that the observed time of fifteen seconds seemed inconsistent with a conventional aircraft sighting, which became a key reason for the case's unidentified classification.

A related sighting occurred about thirty minutes later. A private pilot named Charles Warren reported seeing a similar silver object on the same day at 1345 (2:45 p.m.), flying near Paris, Illinois, at an altitude of 5,000 feet. Warren's object appeared stationary relative to his airplane and later reversed direction, heading northeast toward the Atomic Energy Plant area near Newport, Indiana. The distance between the two sightings (roughly thirty miles) made it geometrically unlikely that both witnesses saw the same object, though investigators considered the possibility that sun reflections off an aircraft might have distorted what the observers saw.

Further investigation by the Air Force's Office of Special Investigations and the Air Technical Intelligence Center revealed no additional information that would identify the objects. The file notes that "further details on the incident will be obtained but it is doubtful if any further information will indicate the possible identity of the object." The Air Force officially classified the Terre Haute sighting as unidentified. The complete case file, consisting of fifteen pages as held by the National Archives, is reproduced below.