Coraopolis, Pa. 2 Mi E of Gty. Pgh. Aprt., November 1957November 1957

On the evening of November 18, 1957, a woman employed as a secretary at the 54th Fighter Group at Greater Pittsburgh Airport saw an unusual object while driving near Coraopolis, Pennsylvania, about two miles east of the airport. The sighting lasted roughly five seconds as she drove past in her automobile without stopping.

The object appeared circular with a convex (domed) top. It had three blinking lights: two red lights about ten feet apart on top near one edge, and one blue light on top near the opposite edge. The lights illuminated the entire top surface of the object. The observer estimated the object was about 150 feet away from her, at roughly the height of nearby tree tops. She believed it was positioned between her point of observation and a hill roughly 100 yards away. The rest of the object was obscured by darkness, and she saw no markings on top.

The observer was considered reliable by her employer. She had worked at the base for eight years and had observed many aircraft. She stated positively that the object was circular and not a conventional airplane. A nearby Army anti-aircraft missile battery located within 428 yards of the sighting was not operating radar at the time and reported no visual sighting. The investigating Air Force officer noted that the object might have been an optical illusion created by an aircraft landing or taking off, but acknowledged that the observer felt certain the object was lower and closer than the distant hilltop and that she would have seen any markings on top had they existed. The source requested no publicity and asked that the incident be kept confidential. No additional information was obtained despite a follow-up request. The Air Force concluded there was insufficient data for evaluation.

The complete case file, including investigative reports and weather information, is reproduced below as held by the National Archives across 7 pages.