Incident No. 71 — 8 or 9 October 1947, daytime, Las Vegas, Nevada. An Air Force Reserve pilot reported observing a trail appearing high in the sky at an estimated speed of 400-1000 MPH. The object producing the trail was not visible. The trail was white as a cloud, and dissipated in fifteen to twenty minutes. The object proceeded in a straight line, then it made an approximately 180° turn of radius five to fifteen miles, and proceeded away toward the direction of first appearance. The weather was described as "almost cloudless."
AMC Opinion: It is difficult to understand why this individual attached any importance to this sighting, and why he did not conclude that the trail was caused by exactly what it appears to have been; that is, an ordinary aircraft flying normally at an altitude too high for itself to be visible, but in the best altitude range to form vapor trails 20,000 - 45,000 feet.