Waverly AFS, IowaFebruary 1961

On the night of February 28 to March 1, 1961, radar operators at Waverly Air Force Station in Iowa detected an unidentified object on their Mark X radar (a ground-based system for tracking aircraft and weather). The object first appeared at 0316Z (3:16 a.m.) on a southwest heading, about 40 miles away. Over the next ten minutes, it moved in a pattern that seemed deliberate: it traveled outward to 125 miles, made a sharp left turn, then headed back inward before disappearing from the radar at 32 miles away, around 0326Z.

The radar station's personnel were all Federal Aviation Administration flight followers considered very reliable by the Air Force. However, the investigation uncovered a complication. The 728th Radar Squadron, which operated the Mark X system, had been experiencing persistent trouble with the radar for some time. The system was prone to multiple registrations and scattered false returns across its entire coverage area. The squadron's intelligence officer noted in his report that "it is felt that this report originated from Mark X problems presently encountered by 768th," though the radar operators themselves disputed this claim and mentioned interference from electronic countermeasures (ECM, or jamming) activity in the area that evening.

The Air Force's intelligence analysis, completed in April 1961, offered two possible explanations. First, the radar blip could have been equipment malfunction, especially given the documented trouble with the Mark X system. Second, if the object was real, it might have been a supersonic aircraft traveling at speeds under Mach 3, although no military flight plans were on file for that time period and no aircraft were confirmed in the area. The Air Force ultimately rated the sighting as unidentified. The full case file, as held by the National Archives, comprises 7 pages.