Air Intelligence Information Report: Unidentified Flying Objects (Short Title: FLYOBRPT) - San Francisco Bay Area, 13 February 1953

This document is an Air Intelligence Information Report (IR-2-53 W) dated 19 February 1953, detailing a sighting of an unidentified flying object over San Francisco, California, on 13 February 1953. The report, authored by Captain Orville E. Bixel of the 28th Air Division, describes an incident involving four Ground Observer Corps (GOC) members stationed at a post on Mount Sutro. Between 1758 and 1820 PST, these observers reported a round, black object accompanied by two silver streaks, which they identified as potential vapor trails. The object was observed moving at a moderately high speed, performing maneuvers described as 'up and down' and a 'zig zag course.' A throbbing sound was reportedly heard as the object passed overhead. The object was first sighted over the ocean approximately four miles away and eventually disappeared from view over the city of San Francisco. The estimated altitude was 10,000 feet. The report notes that there were no radar contacts associated with the sighting. The document includes references to a San Francisco Examiner article from 14 February 1953, which reported that thousands of people in the Bay Area observed similar objects during the early morning and evening hours of 13 February. The official conclusion provided by the Air Intelligence Information Report, supported by the San Francisco Weather Bureau and astronomer Dr. Otto Struve, is that the sightings were the result of a temperature inversion. Dr. Struve explained that a mass of warm air encased between two layers of cold air acted as a reflector, creating the visual phenomena. The report is marked as unclassified and includes various routing slips and administrative metadata, indicating its processing through military intelligence channels, including the Air Technical Intelligence Center (ATIC) at Wright-Patterson AFB. The document also contains a list of other sightings from February 1953, suggesting a broader effort to catalog and evaluate reports of unidentified aerial phenomena during that period.