TINKER AFB, OKLAHOMAOctober 1954

On October 23, 1954, radar operators at Tinker Air Force Base in Oklahoma picked up an unusual target on their FPS-10 radar scope (a type of radar that displays moving objects on a circular screen). The target appeared to be moving at an extremely high speed, well over 3,200 nautical miles per hour when first detected. Then something unexpected happened: the object slowed dramatically to 250 nautical miles per hour. It also changed direction, shifting from a heading of 340 degrees to 160 degrees as it moved away from the radar site.

The radar blip looked similar in size, shape, and brightness to a standard IFF return, which is a radar signal that friendly aircraft transmit to identify themselves. This similarity led investigators to suspect the sighting might not have been a real object at all.

The Air Force's technical intelligence center examined the case and concluded that radar frequency interference most likely explained the entire incident. Specifically, the evaluation suggested that a signal from a nearby beacon (the AN/APW-11 system) had probably caused the radar to detect a false target. The report noted that if two radar signals were drifting toward each other in frequency, they could briefly overlap and create the appearance of a moving object on the scope, then separate again. The file indicates this interference explanation accounts for the object's unusual characteristics: its sudden speed changes and directional turn.

The Air Force officially evaluated this case as unknown, though the available evidence pointed toward a radar malfunction rather than anything unexplained. The complete case file, consisting of 7 pages as held by the National Archives, is reproduced below.