Richmond, Calif., April 1952April 1952

On March 31 or April 1, 1952, a worker at Port Chicago Naval Yard in the San Francisco Bay Area reported seeing an unusual bright light moving over Suisun Bay near Richmond, California. The man said the object was round and very large, though he could not estimate its exact size or altitude. According to his account, it moved faster than any aircraft he had seen and performed maneuvers that no ordinary plane could execute. He also reported that the object left a streak of flame as it traveled northward.

The Air Force received the report on April 4, 1952, when the witness called Hamilton Air Force Base. Investigators noted that weather conditions at the time were clear with unlimited visibility and calm winds. They checked flight records and found that an F-89 fighter jet was in the area on March 31 at around 1:31 a.m., and noted it was possible the aircraft had its afterburners turned on. The witness had relatively little knowledge of aircraft or aerodynamics, which led investigators to rate the reliability of his report as low.

The case file noted that the exact date of the sighting remained uncertain, with conflicting information suggesting it occurred either on March 31 or April 1. The description of a bright light leaving a flame trail resembled a meteor, but the witness's claim that the object made impossible aerial maneuvers set it apart from conventional explanations. The Air Force concluded the sighting was unknown.

The full case file, consisting of 10 pages, is reproduced below as held by the National Archives.