Project 10073 Record Card and Spot Intelligence Report — Terre Haute, Indiana, 9 October 1951

This document collection details an unidentified aerial phenomenon (UAP) incident occurring on 9 October 1951 near Terre Haute, Indiana. The primary witness, Claude W. Sonner, a Chief Aircraft Communicator for the Civil Aeronautics Authority (CAA) at Hulman Municipal Airport, reported observing a round, silver object without fins or protrusions passing directly overhead at 1342 hours. Sonner, described as a 'hard-headed' witness, estimated the object's size to be equivalent to a half-dollar coin held at arm's length. The object traveled in a straight, southeasterly path, disappearing over the horizon in approximately 15 seconds. Sonner noted the absence of vapor trails, noise, or other protrusions. A second sighting was reported on the same date at 1345 hours by a pilot named Charles Warren, who was flying a private plane near Paris, Illinois. Warren observed a similar silver object at an altitude of 5,000 feet that appeared stationary before reversing its direction and traveling northeast, passing south of the Atomic Energy Plant at Newport, Indiana. The Air Force conducted an investigation through the 12th District Office of Special Investigations (OSI), interviewing both witnesses. Electronic surveillance via a TPS-13 radar unit at Rockville, Indiana, yielded no corresponding data. Weather conditions were reported as clear with bright sun and no haze. Official Air Force intelligence reports, including those from the Air Technical Intelligence Center (ATIC), suggest the possibility that the objects were jet aircraft distorted by sun reflection, though the case remained officially classified as 'unidentified.' The documents include various internal communications, including teletype messages between the Eastern Air Defense Force, ATIC, and the Office of Special Investigations, requesting immediate field investigations and follow-up reports in accordance with Project Grudge protocols. Despite the thorough documentation and follow-up, the final status of the investigation concluded that no additional information could be obtained and that it was doubtful further inquiry would lead to a positive identification of the object.