Project Grudge Report: Unidentified Aircraft Sighting, San Francisco, California, 1 August 1949

This report details an investigation conducted by the Office of Special Investigations (OSI) into a series of sightings of unidentified aerial objects near San Francisco, California, on 1 August 1949. The investigation was initiated following reports from multiple witnesses, including a sales clerk, a commercial fishing boat captain, and a Reverend, who all claimed to have observed multiple silvery, oval or square-shaped objects in the sky while near the Golden Gate. Witnesses described the objects as traveling in formation at varying speeds, with some estimating them to be faster than jet aircraft and others slower. The objects were reported to have no visible means of propulsion, no exhaust, and made no sound. The OSI conducted extensive interviews with these witnesses, noting discrepancies in their accounts regarding the objects' altitude, shape, and direction of flight. The investigation also involved checking flight clearance records with the Civil Aeronautics Authority and local airports, which revealed that very few aircraft in the area filed flight plans, making it difficult to identify known traffic. Furthermore, the OSI checked with military commands, including the Sixth Army and the Office of Naval Intelligence, to determine if any radar installations were capable of tracking objects in the area. A critical finding of the investigation was the confirmation from Air Force radar installations at Treasure Island and Fort Baker that they regularly released radar testing devices, referred to as 'kites,' twice daily at 1000 and 1600 PST. These devices were constructed of aluminum sheet, were roughly diamond-shaped, and were carried aloft by gas-filled balloons. When the balloons burst, the 'kites' would drift earthward. The report concludes that these devices were the most likely explanation for the sightings, despite the varying descriptions provided by the witnesses. The investigation was closed after obtaining sketches and signed statements from the primary witnesses, with the OSI noting that while the witnesses were convinced of their accounts, the physical evidence of the radar testing program provided a plausible, non-anomalous explanation for the phenomena.