Date: Sat, 08 Jun 2002 12:54:25 -0400
Subject: 19 Feb 1958
From: joel carpenter <>
Forwarded for the record from Project 1947 list...

Greetings list -
Is anyone aware of this bizarre radar incident, mention of which I found in the British Air Ministry 'Radar and Signals Advisory Board' papers, marked 'Top Secret' and dated 1958:


"...significant and reliable reports on unusual radar responses have been received within the last month:

"a) whilst tracking Soviet aircraft on 19th February 1958, technical personnel of an American radar site at ASOIWAYAMA, Hokaido, observed an unusual response on the FPS-6 height-finder. The response was from the area 40'30" N, 137'30" E, over the Sea of Japan, approximately 80 n.m. from the Russian coast, and nearly 200 miles from the radar site.

"The response developed rapidly to a dense cloud that expanded to cover an area some 65 miles long and 25 miles across, which rose from an altitude of 3,000 ft to a final altitude of 46,000 ft. All five Russian aircraft tracks in the area proceeded to the general vicinity of the response. Observers were unable to describe the return and associated Soviet reaction in terms of any previous experience. Rapidity of developmnent and Soviet reaction would appear to rule out weather phenomena or radar malfunction.

"The fact that the dense cloud described above rose from low level to high altitude in a short space of time would tend to rule out all conventional forms of window. We have one report that the Soviets have experimented with metallised dust as a passive form of ECM, and it is possible that some form of low level air burst might have been used over the Sea of Japan. Observers at the American radar site concerned, stated that the cloud nearly resembled that of a very large explosion. We have no record of an atomic or nuclear burst in the area, and a qualified observer has stated that an atomic explosion does not produce the radar effects noted.

"No further information is available. The event at Hokaido was observed by a civilian scientist as well as by officer personnel of the radar station and the report is accepted as reliable.

"The events described in these reports are not understood. The Ministry of Supply and the Air Ministry would welcome the assistance of Members of the Board in explaining them."

Any ideas?
Dave Clarke