Research news
Bitesized UFOs #024: Korean War UFO
20th June 1952: during an attack run on a North Korean target, pilots from a flight of US Marine Corps F4U Corsairs spotted a white circular or oval shaped object orbitting over or near their objective. The flight leader dived on the UFO but it shot away and disappeared. Four pilots provided reports for US Air Force intelligence officers detailing what they saw. Another little known case from the past eight decades, brought to you by Bitesized UFOs.
See more (external link) 
https://www.youtube.com/watch?v=SPizXJ_id68