Project Blue Book Case #4489. On November 1, 1956, an unidentified object was observed from an aircraft approximately 60 miles east of St. Louis, Missouri — placing the sighting over the rural flatlands of southern Illinois. The airborne observation point suggests the witness was a military or civilian pilot, providing a vantage point unavailable to ground observers.
The St. Louis area was home to Scott Air Force Base (headquarters of the Military Air Transport Service) and the McDonnell Aircraft Corporation, which produced the F-4 Phantom II and other military aircraft. The region's airspace was well-documented, and the object did not match any known traffic.
Airborne sightings by pilots were among the most valued reports in the Blue Book files, as pilots were trained observers with direct experience in estimating the speed, altitude, and distance of aerial objects. The case was classified "Unknown."