Fort Monmouth radar-visual incident

Record summary

What happened During radar training at Fort Monmouth, operators reported an unusually fast target that appeared to track or pass near an aircraft. A T-33 crew in the area separately reported a disc-like or translucent object below them. The temporal relationship between the radar traces and visual sighting made the incident influential in the creation of Project Blue Book, but surviving accounts do not establish that both systems observed the same target. Air Force review found scope calibration and operator-training issues and concluded that weather effects or conventional traffic could account for the radar component. Evidence Military radar-operator statements, an aircrew visual report and internal Air Force investigation. No preserved radar recording is publicly available. Explanations considered Anomalous propagation, radar calibration error, balloons and misidentified aircraft have been proposed. The separate radar and visual observations may have been combined after the event. What remains uncertain Most descriptions derive from retrospective Air Force summaries rather than raw instrument data. Timing, altitude and track details vary between accounts. Primary source The Report on Unidentified Flying Objects — Project Gutenberg Further source trail Project Blue Book records — https://www.archives.gov/research/military/air-force/ufos