PROJECT 10073 RECORD CARD - CASTLE AFB CALIFORNIA

On 27 February 1957, at 0545Z, personnel at Castle Air Force Base in California observed nine S-shaped objects on CPN-18 radar sets. The objects were tracked for 24 seconds, covering approximately 40 miles, and were estimated to be traveling at a speed of 6,000 miles per hour. The targets appeared as sharp returns, comparable in size to a B-52 aircraft on the radar scope, and followed an almost straight path toward the center of the scope before being lost in ground clutter. A KC-97F aircraft in the vicinity was contacted, but the only crew member to report anything unusual was a radio operator who observed what he believed to be shooting stars. Intelligence evaluations concluded that the radar returns were likely the result of atmospheric phenomena or equipment malfunction, noting that the observed speed was inconsistent with known aircraft performance. A technical representative from Gilfilian and Brothers Incorporated, who serviced the radar equipment, suggested that similar returns had been experienced at other northern bases and were potentially caused by atmospheric conditions. Colonel Gordon C. Hoffman, of AFOIN-4E1, formally reviewed the report and concluded that the shooting star observations were likely unrelated to the radar returns, suggesting that equipment malfunction was a strong possibility for the anomalous display.