On june 11 1951, a Lockheed Neptune P2V-3W (an upped electronic subtype) dissapeared on a mission over eastern Siberia and Vladivostok. The Neptune belonged to VP-6 and flew out of NAS Yazuka in Japan, trying to locate Soviet military installations in the era, before satellites and other electronic surveillance took over that job. The plane was most probably shot down by Soviet fighters and most likely Lavochin La-11's. Soviet never admitted shooting them down and US also never admitted the plane was missing until later that autumn, due to the sensitive character of the mission. In this period of late 1940's and early '50's, several US planes was 'lost' on similar missions, many of them over the Baltic and Asia in addition to the Pacific. The crew of 10 in this plane is MIA to this day.