Incident #71 Sighting Report — Las Vegas, Nevada, 8 or 9 October 1947

This document details Incident #71, a sighting reported by an Air Force Reserve pilot near Las Vegas, Nevada, on either October 8 or 9, 1947. The witness observed a white, cloud-like trail high in the sky, which persisted for fifteen to twenty minutes. The object associated with the trail was estimated to be traveling at 400 to 1000 mph. It moved in a straight line before executing a 180-degree turn with a radius of five to fifteen miles, eventually heading back toward its point of origin. The weather at the time was described as almost cloudless. The official opinion from the Air Materiel Command was dismissive of the sighting's significance. Investigators argued that the witness should have concluded the trail was simply produced by an ordinary aircraft flying at an altitude between 20,000 and 45,000 feet, where conditions are optimal for vapor trail formation. The report further analyzes the incident in the context of 'fireball' sightings. While the description of the trail matched that of a fireball, the investigators noted that the reported 180-degree turn made the fireball hypothesis 'almost fatal.' They concluded that a meteoric explanation was highly improbable due to the curved trajectory and that it was more likely that an aircraft was under observation. The document is part of the Project Grudge/Blue Book files and reflects the military's efforts to categorize and explain various aerial phenomena reported during the late 1940s.