Cincinnati, OhioJune 1956

On the morning of June 21, 1956, at 0836 (8:36 a.m.), two meteorologists and an electronics engineer were watching a radar scope at a facility in Cincinnati, Ohio. They were monitoring weather patterns when an unusual echo appeared on their screen at 068 degrees. The bright signal showed up at the 20-mile range ring, with the same brightness as ground clutter, which is radar noise caused by reflections bouncing off the ground.

As the radar scanner made its second sweep about six seconds later, the center of the reflective field had moved one to two miles. The first echo remained bright, and a second echo appeared to the northeast of the first. After another scanner sweep, the sharp echoes had scattered and faded completely. Before disappearing, the scattered areas took on what the observers described as the shape of small wings.

The entire sighting lasted about nine seconds. One of the three observers provided a written account of the event in August, noting that he and his colleagues agreed the reflective field was not caused by weather or other types of interference.

The Air Force's investigation centered on the radar findings. A colonel from the Air Force's Office of Intelligence concluded that the signal was most likely caused by ground clutter, specifically by changes in the atmosphere's ability to refract radio waves. This phenomenon, called anomalous propagation, happens when radio beams bend and strike the ground at unusual angles. The Air Force recommended that future UFO radar reports include the radar set's identification and an estimate of the target's size based on what appears on the scope. The case file shows no final conclusive determination beyond the ground clutter assessment.

The full case file is reproduced below as held by the National Archives, 15 pages.