Misawa AFB, Japan, August 1949August 1949

On August 23, 1949, at 1530 (3:30 p.m.), four experienced U.S. Air Force pilots standing on the front steps of the 47th Fighter Group Operations Building at Misawa Air Force Base in Japan spotted an unusual object in the sky about three miles away. One lieutenant noticed it first because of its color and motion, then pointed it out to the other three officers nearby. The object appeared yellow or silver and rectangular in shape, roughly 6 feet tall and 30 feet long. It resembled a tow target (a device towed behind aircraft for gunnery practice), though the pilots discussed whether it could actually be one while watching it.

The object moved in a northerly direction at an estimated speed of 400 to 500 miles per hour, traveling at about 200 feet altitude or less and roughly paralleling the coastline. The pilots observed it for approximately 50 seconds as it traveled about five miles in view. The object moved on a steady, even course with no visible exhaust, propulsion, lights, or support structure. An F-80 jet warming up nearby was loud enough that the observers could not tell whether the object made any sound. The object eventually disappeared behind a parked B-17 bomber, possibly obscured by heat waves from the F-80.

The Air Force investigation noted that other aircraft were in the air at the time, including three T-6s and five F-80s, but pilots of those planes reported seeing no unusual objects. No radar sites were operating in the area due to routine maintenance. The U.S. Navy reported no activity in the area. The observers ruled out a Japanese kite because of the object's extreme speed and confirmed it was not an airplane based on its shape. The file contains no stated conclusion on what the object was, though investigators noted that roads in the area could have allowed the object to be towed from the ground.

The full case file is reproduced below as held by the National Archives and spans 7 pages.