Iwo Jima, June 1953June 1953

On June 17, 1953, a military transport plane flying near Iwo Jima, Japan, detected an unidentified object on radar that neither the crew nor any known aircraft could explain. The plane was on a routine round-trip flight from Yokota Air Force Base when its radar operators made three separate contacts with the target over roughly 3 and a half minutes each.

During the first radar sighting, the object appeared about 20 miles away and closed to within half a mile of the aircraft. The radar operator estimated its speed at 600 to 800 miles per hour. The second contact showed the target about 6 miles ahead, also traveling at roughly 500 miles per hour. The third sighting was similar to the first, with the object approaching from behind and disappearing after closing to half a mile.

The radar itself was checked and found to be working properly with no signs of interference. Five other crew members confirmed seeing the target on the radar scope. One flight scanner reported seeing two red lights and one white light visually, though the official assessment suggested these lights likely came from Iwo Jima itself, which was nearby.

The plane's pilot was told that no other aircraft were scheduled to be in the area for approximately two hours. The weather was clear with some scattered clouds at lower altitudes. The Air Force investigation found no conventional explanation for the radar contacts. While the brief visual observation by one crew member was noted, it was considered inconclusive. The official evaluation listed the sighting as unknown, though suggestions of anomalous radar propagation or atmospheric conditions were mentioned as possible effects that might have confused the radar returns.

This case file spans 70 pages as held by the National Archives in microfilm T1206, Roll 18.