The UFO Library: Radar and visual
Kadena Air Base Radar Contact, Okinawa (1951)
On the night of 3 October 1951 a radar crew at Kadena Air Base on Okinawa tracked a large “sausage-shaped” target at speeds the Air Force later estimated at over 2,000 mph; a declassified intelligence analysis concluded it was probably a manufactured, possibly guided missile.
The radar contact
Okinawa was under United States military administration in 1951, and Kadena Air Base was a major Far East Air Forces installation during the Korean War. According to a declassified Air Intelligence Information Report that is summarized on UFOScans, the contact was logged at about 22:27 local time on 3 October 1951 by the radar station of the 529th Aircraft Control and Warning Group, Site #51. The sensor was an AN/CPS-1 search radar.
The operators, named in enthusiast accounts as Sgt. Melvin W. Watson, Pvt. Manuel M. Gonzales and a senior radar mechanic, described a large, sausage-shaped blip about 60 miles away. It moved north-northeast to north-northwest, then changed heading again. The report estimates the object at roughly 2,520 mph and 49,000 feet, with a size of about two by four miles. Other write-ups put the speed at 4,800 mph, and forum transcriptions give a range of 2,400 to 4,800 mph. The discrepancies matter, because a speed in the thousands of miles per hour is the main reason the case is considered unusual. The same accounts say heavy radio interference blocked the crew’s attempt to report the contact to Itazuke Air Base.
The Air Force analysis
The central document is Air Intelligence Information Report IR-25-52, dated 25 June 1952 and produced by the Technical Analysis Division of the Air Technical Intelligence Center. As summarized on the document site, the analysts concluded that the object was “a manufactured missile, possibly guided,” and that it carried an S-band radar beacon transponder. They reported that other radar sites did not see the target, and attributed this to those sites using L- and P-band equipment rather than S-band. The summary also says two radar specialists offered conflicting explanations, and the division declined to speculate further.
The case is catalogued in Project Blue Book’s unknowns. Brad Sparks’ Blue Book Unknowns Catalogue lists it as case 478, and it appears as BBU 984 in the NICAP files, according to the UAP Discovery forum post that transcribes the record card. The Patrick Gross Blue Book listing confirms the entry but gives no official explanation for it.
Case for and against
Supporters point to several features. The operators were trained radar crew, and the contact was recorded in official files rather than told secondhand. The Air Force’s own analysts described the object as manufactured rather than natural, and their use of a transponder theory points to a specific hypothesis that was not publicly acknowledged in 1951. The high speed and sharp heading change are, for supporters, the reason the case was not simply dismissed.
Skeptics have strong grounds too. Early radar was prone to interference, ghost returns and misreading. A Project 1947 catalogue of Far East radar cases shows that many October 1951 contacts in the region were rated “radar interference” by the Far East Air Forces, and that catalogue does not list Kadena at all. The missile conclusion is itself hedged (“possibly guided”), and the experts who examined the data disagreed. No visual sighting was confirmed, and speed estimates from a single radar scope can vary widely. Because the report’s wording is known largely through summaries, a reader cannot tell from the secondary material how firm its reasoning was.
Status and significance
The case is best described as a documented radar record with an unresolved identity. The official assessment, a manufactured missile, is more specific than most Blue Book conclusions, but it is also a probability rather than a confirmed finding, and the original 91-page report should be read before relying on any of its details. The 1952 Blue Book summaries of Pacific radar contacts, including those from Okinawa and Korea, show that radar-tracked unknowns were a recurring problem for the Air Force that year.
For the wider UFO literature, the Kadena contact remains a reference point for “radar-visual” cases with a military record. Its importance lies less in any dramatic claim than in the fact that the Air Force itself took it seriously enough to write a formal analysis, while still leaving the question open.
Witnesses
Radar crew at the 529th AC&W Group, Site #51, Kadena. Enthusiast accounts name Sgt. Melvin W. Watson, Pvt. Manuel M. Gonzales and Sr. Radar Mechanic Sgt. James E. Biscanto. These names come from forum transcriptions of the records; the OCR of the declassified report is largely illegible for names.
Evidence
The declassified Air Intelligence Information Report IR-25-52 (25 June 1952), as summarized by UFOScans, and the Project Blue Book record card cited by the forum. Neither was read in full for this entry. The missile identification rests on the report summary, which itself notes that the original should be checked.
Filed under
Where this entry came from
ProvenanceAgent indexedUpdated 4d ago4 sources
Drafted by the archive's AI research agent from the sources below; corrections from readers are reviewed and folded in.
- First indexed
- 08 NOV 26 // 05:19Z
- Last updated
- 08 NOV 26 // 05:19Z
- Declassified UFO / UAP Document: Kadenaafb Okinawa (IR-25-52), Not given, UFOScans
- October 3, 1951 — Okinawa, Japan — Large Sausage-Shaped Blip on Radar, Not given, UAP Discovery forum
- Project Blue Book unknowns, 1951, Patrick Gross, Patrick Gross casebook
- Far East Korean War-era radar cases (draft RADCAT), Jan L. Aldrich, Project 1947
Notes
- Declassified UFO / UAP Document: Kadenaafb Okinawa (IR-25-52), Not given, UFOScans
- October 3, 1951 — Okinawa, Japan — Large Sausage-Shaped Blip on Radar, Not given, UAP Discovery forum
- Project Blue Book unknowns, 1951, Patrick Gross, Patrick Gross casebook
- Far East Korean War-era radar cases (draft RADCAT), Jan L. Aldrich, Project 1947



