Project 10073 Record Card — El Centro, California, 21 April 1958

This document is a Project 10073 record card and associated teletype communication regarding an aerial sighting that occurred on April 21, 1958, near El Centro, California. The primary witness, a German national employed as a GS-11 with the 6511th Test Group (Parachute) at NAAS El Centro, observed the object while sitting in a convertible with his wife. The witness, described as a qualified aerial observer due to his professional duties, reported seeing a delta-shaped, black object with an indistinct, recessed trailing edge. The object was estimated to be the size of a silver dollar held at arm's length and featured numerous large, bluish-gray lights on its underside that flickered intermittently. The lights were noted as being bright on the perimeter but indistinct in the center. The object traveled from south to north on a heading of approximately 010 degrees, passing directly over the observers at an altitude of 45 degrees above the horizon. The sighting lasted for approximately one minute and ended when the object disappeared into a lighted area to the north. The witness reported no sound, no trail, and no exhaust. Weather conditions were clear with unlimited visibility. Despite the witness's professional background, the reporting officer concluded that the object was likely an aircraft, noting on the document that it was 'not an UFO report, but an unidentified ac report.' No physical evidence was recovered, and no radar contact was reported.