Unidentified flying object on radar near Tokyo in 1952

Summary

In September 1952, a classified U.S. Air Force report documented an unidentified aerial phenomenon near Tokyo International Airport. A radar operator observed an object on the radar screen moving at an estimated speed of 40 to 60 miles per hour, at an altitude of less than 3000 feet. The object did not maintain formation and moved in various directions, but always within the northeast quadrant of the airport. The radar registered an echo similar to that of a C-124 aircraft, but the object could not be visually identified. The report suggested it could be migratory birds, although observers could not explain the size of the echo.

The report also noted that another radar at Shiroi, located 22 miles northeast, recorded the same phenomenon. Officers considered the possibility that large migratory birds, such as snipes and sandpipers, could explain the echo. However, a speculative hypothesis was also raised that the birds might have passed through areas with radioactive material, which could have altered the radar echo. Despite these theories, the report did not reach a definitive conclusion and was filed with a low evaluation due to the lack of concrete data.