Project 10073 Record Card and Incoming Message — Hill AFB, Utah, 5 July 1950

On July 5, 1950, at 1540 hours MST, three staff sergeants stationed at the Hill Air Force Base Radar Station in Utah observed an unidentified aerial object. The object was estimated to be flying at an altitude of 25,000 feet on a course of approximately 120 degrees, passing almost directly over the base. The witnesses observed the object for approximately three minutes. They described the craft as being 50 feet in length, circular in shape, with a thickness ratio of approximately 4 to 1. The object was noted to be silver in color, and the witnesses reported no sound or exhaust trail. The estimated ground speed of the object was between 500 and 700 miles per hour. Although the radar station attempted to track the object, the radar set was switched on only after the sighting had already begun, and the object disappeared before the equipment had warmed up sufficiently to establish a track. The incident was reported by the 16th OSI District at Hill AFB to the Director of Special Investigation at the Department of the Air Force in Washington, D.C., on July 6, 1950. The report, filed under Project 10073, requested guidance on the extent of the investigation required and whether future reports of similar sightings were desired. The document includes a record card summarizing the sighting and an incoming classified message detailing the event.