Incident #89 — 100 mi. W of Kansas City, Missouri — 6 July 1947

This document contains an official report and subsequent evaluation of an unidentified aerial phenomenon incident (Incident #89) that occurred on July 6, 1947, near Clay Center, Kansas. The report, filed under Project SIGN, details an observation by an Air Force pilot who reported seeing a very bright, disc-shaped object approximately 30 to 50 feet in diameter. The pilot observed the object at an altitude of 11,000 feet, noting that it appeared to be traveling at 210 mph on a parallel course. The object was first seen as a flash, and the pilot reported that it disappeared when the aircraft turned toward it. The evaluation of the incident, conducted by Project SIGN, concludes that there is no direct astronomical explanation for the sighting. However, investigators suggest it is probable that the witness observed a reflection of the sun on thin clouds or ice crystals, noting that the object appeared at the 11 o'clock position, opposite the sun. The report highlights a significant inconsistency in the pilot's testimony, as he initially claimed the object was at the top of a water tank before later stating it was at 11,000 feet. This discrepancy led investigators to suggest that a reflection on a river or railroad track might be a more plausible explanation if the object was indeed at a low altitude. The document also includes administrative correspondence from the Air Materiel Command at Wright-Patterson Air Force Base, dated January 5, 1949, regarding the collection and investigation of such reports under Project SIGN, and provides an index of evaluations extracted from the Project GRUDGE report, which categorizes various incidents by their likelihood of being astronomical, balloons, or other phenomena.