Air Force Intelligence Kept 1954-1956 UFO Files Redacted
By June Hargrove ·
Blacked-out lines and omitted pages still mask what the 4602D Air Intelligence Service Squadron saw in the skies between 1954 and 1956.
The record is not a report, a transcript, or a memo. It is a map of where the reports are kept. Specifically, the US National Archives catalog entry for NAID 23857158 describes a series titled "Copies of the Case Files of the 4602D Air Intelligence Service Squadron on Sightings of Unidentified Flying Objects (UFOs)."
In the world of records, a "copy" is a distinct entity from an "original," and a "redacted copy" is a distinct entity from an "unredacted" one. The catalog entry for this series makes a sharp distinction: it notes that "unredacted copies of this series can be found" in a separate series, identified as National Archives Identifier 23857157, which covers the years 1954–1956.
1954–1956
The 4602D Air Intelligence Service Squadron operated during a window of high atmospheric tension. According to the catalog, the case files in question span 1954 to 1956. To understand the environment that produced these files, one can look to the public record of the regional hubs of air defense during that era. In Colorado Springs, Peterson Air Force Base—now Peterson Space Force Base—served as a critical node. Developed as a World War II air support base, it evolved into a center for Cold War air defense, supporting operations at the Chidlaw Building and the nearby Cheyenne Mountain Complex. It eventually became the home of the North American Aerospace Defense Command (NORAD).
While the catalog entry does not explicitly detail the day-to-day operations of the 4602D, the existence of a dedicated "Air Intelligence Service Squadron" producing case files on unidentified sightings fits the pattern of the period's surveillance priorities. The files were not isolated; they were part of a wider net designed to monitor the skies for any deviation from the known.
Project Blue Book Office
The custody of these sightings records reflects a shifting administrative chain. The catalog entries for related series show that the "List of Sightings" was not held by a single office for the duration of the phenomenon's peak. From 1947 to 1951, the Technical Intelligence Division maintained the series. From 1951 to 1952, the responsibility shifted to the Air Technical Intelligence Center. Finally, from 1952 to 1969, the series was maintained by the Project Blue Book Office.
This handover suggests a standardization of how the Air Force processed "sightings." The 4602D files from 1954–1956 fall squarely within the period of Project Blue Book's oversight. The records move from technical intelligence—focused on the physical properties of aircraft and electronics—to a centralized office dedicated to the investigation of UFOs. This transition tracks the government's movement from treating unidentified objects as purely technical intelligence gaps to treating them as a categorized administrative problem.
National Archives Identifier 23857157
The catalog indicates that the 4602D case files are not the only media associated with these investigations. Related series entries list "Project Blue Book Motion Picture Films" and "Sound Recordings Relating to Project Blue Book Unidentified Flying Object (UFO) Investigations." These indicate that the evidence gathered by the 4602D and its contemporaries was multi-modal, consisting of written case files, visual recordings, and audio testimonies.
Beyond the National Archives, other repositories hold fragmented pieces of this puzzle. The CIA Reading Room contains a 1953 report from a scientific advisory panel on unidentified flying objects. The NSArchive at George Washington University holds more recent records, including 2025 court filings from the Northern District of Illinois and redacted EPA meeting points. These documents exist in the same ecosystem of transparency and redaction as the 4602D files.
The central tension of NAID 23857158 is that it is a series of copies. The catalog directs the researcher away from these copies and toward NAID 23857157 for the unredacted versions. This means that the versions of the 4602D files listed under 23857158 contain gaps—blacked-out lines or omitted pages where the government determined the information remained sensitive, even decades after the events of 1956.
The catalog entry stops there. It tells us the files exist, who held the lists, and that a cleaner version of the 4602D's work is stored under a different identifier. It does not tell us what the 4602D actually saw in the skies between 1954 and 1956, or why the copies in one series remain redacted while those in another do not.