In November 1964, American naval personnel reported unidentified aircraft in the Caribbean, including an encounter involving the destroyer USS Gyatt and a Navy F-8C pilot. Initial accounts suggested an exceptionally fast, high-flying target. A later CIA analysis reached a more limited conclusion: the reviewed radar photographs indicated a much slower relative track, and analysts proposed a conventional delta-wing fighter for the principal encounter.
The surviving correspondence does not name a confirmed aircraft or operator. It also distinguishes the 19 November encounter from other reports during the same period. This makes it a useful example of how an alarming initial description can change when the underlying recording is examined, without every observation receiving a final identification.
The reports and the request for a closer look
The six-page file contains a memorandum dated 1 February 1965 and a responding assessment dated 11 February. The first memorandum describes information about a UFO near Puerto Rico during 18–24 November 1964. It records an earlier suggestion, relayed through Navy correspondence, that the target was a YF-12A. The CIA writer says efforts had persuaded naval intelligence that it was not that aircraft or a similar Lockheed type. Neither the initial suggestion nor its rejection establishes what the target actually was.
The writer requested a scientific evaluation of original Navy radar film and associated prints. The memorandum refers to underlying traffic, documents, film and photographs being supplied for study and returned afterwards. Those materials are important to the original investigation, but they are not reproduced in this six-page release. A modern reader can examine the memoranda’s descriptions and conclusions, rather than independently repeat the radar analysis.
The 19 November encounter
The responding assessment describes a Navy F-8C pilot who saw a delta-shaped object approximately the size of a jet fighter on the evening of 19 November. The pilot estimated performance considerably greater than his own aircraft and a speed above Mach 3. USS Gyatt separately reported a radar track exceeding 3,000 knots. These are the estimates and reports which prompted concern; they should not be presented as the CIA’s verified final measurements.
Analysts examined photographs of the SPS-49 radar’s plan-position display. Their account describes a sustained track extending beyond 300 nautical miles, a course about 165 degrees relative to the ship and a relative speed around 400 knots. Relative speed is the motion recorded in relation to the observing ship. It is a different claim from the initial multi-thousand-knot description, and the source does not justify substituting one number for an independently measured airspeed.
The radar was undergoing an evaluation test programme, which explains why a recording camera was in use. The fact that a test was taking place is relevant to the recording’s provenance; the memorandum does not simply dismiss the target as a test artefact. The assessment treats it as an aircraft track while rejecting the extraordinary performance originally attributed to it.
What the CIA concluded
Donald F. Chamberlain, Assistant Director for Scientific Intelligence, signed the 11 February memorandum. It states that detailed examination of the radar photography and associated correspondence did not support a high-altitude, ultra-high-speed UFO north of Puerto Rico during the reported period. It nevertheless recognises apparently valid aircraft tracks or observations near the Atlantic Fleet Weapons Range on 16, 17, 18, 19 and 24 November.
For 19 November, the proposed explanation was probably a delta-wing fighter with better climb performance than the F-8C in the 50,000-foot altitude regime. For the other dates, the document says the limited correspondence suggested unidentified aircraft. An unidentified aircraft is not automatically an extraordinary vehicle: the phrase can describe an aircraft whose type, identity or operator has not been established.
The memorandum considers whether reconnaissance connected with scheduled missile tests could provide a motive. It notes that Gyatt was 325 nautical miles from Cuba’s eastern tip during the 19 November incident and discusses the range and reconnaissance capability of the MiG-21. Crucially, it explicitly says there was no evidence at hand either to establish or exclude MiG-21 reconnaissance activity based in Cuba. That possibility is therefore a hypothesis in the assessment, not an identified Soviet or Cuban flight.
Assessment: Possibly Explained
UKPX classifies the case as Possibly Explained. The primary analysis provides a specific conventional-aircraft explanation and materially reduces the exceptional speed claim. It does not identify an individual aircraft, prove a MiG-21 mission or demonstrate that every report between 16 and 24 November had the same cause. Closing the entire episode as an established identification would overstate the document.
The Radar records feature reflects the documented review of Navy radar photographs. It does not mean the original film is available on this page. No separate triangle feature is assigned: the source’s delta-wing description was part of the conventional-fighter assessment, and should not silently turn into a claim for a large triangular craft. The surviving evidence supports a history of reports and technical assessment, not a confirmed extraordinary performance demonstration.
Dates, location and the released record
The incident year is 1964. The February 1965 dates belong to the memoranda, and the 2026 markings concern release and archive handling. The file’s catalogue title uses 1965, but that is not the year in which the naval encounters occurred. The reviewed pages include cover and control sheets as well as the substantive assessment; no claim is made that the referenced radar film or all underlying Navy attachments have been reviewed.
The map uses a broad GeoNames reference for Puerto Rico, rounded to 18.248, −66.500. It represents the regional association stated in the file, not a ship position, an aircraft track, a location on land or a visitor site. The memorandum supplies a distance from Cuba’s eastern tip without a usable bearing, so no exact sea position is reconstructed from it. The encounters were reported in the surrounding sea and weapons-range context; the island reference is deliberately approximate.
Primary source: CIA-UAP-D022, Unidentified Flying Object, memoranda of 1 and 11 February 1965, six-page original from the PURSUE released-file collection. All six pages were read; the two-page 11 February assessment was also visually checked against the scan. The reproduced assessment page is an official U.S. federal government work and is credited as public-domain document imagery. Sources and map reference checked 13 November 2026.