Summary:

On 10 July 2026, the United States Department of War released the fourth tranche of declassified Unidentified Anomalous Phenomena (UAP) files under the Presidential Unsealing and Reporting System for UAP Encounters (PURSUE). This tranche added approximately 40 files to the public corpus, including three foundational historical documents from 1948–1949, multiple new military infrared sensor videos from different locations and time periods, and additional imagery. The historical documents provide a continuous primary source record of the earliest formal U.S. government investigations into unidentified aerial phenomena, spanning Project SIGN, a joint Top Secret Air Force–Navy intelligence assessment, and a classified February 1949 scientific conference at Los Alamos attended by nuclear weapons scientists including Dr. Edward Teller. All material is presented as unresolved and is now available on WAR.GOV/UFO.

Detailed Report

1. PURSUE Release 04

The Department of War issued the fourth tranche of declassified and historical Unidentified Anomalous Phenomena files on 10 July 2026 as part of the PURSUE program. The release added approximately 40 files in total. The official announcement, attributed to Assistant to the Secretary of War for Public Affairs and Chief Pentagon Spokesman Sean Parnell, stated that the collection continues to be housed on WAR.GOV/UFO and that additional files will be released on a rolling basis.

 

2. Historical Investigations from 1948–1949

2A. DOW-UAP-D097 – Project “SIGN” Initial Report, 23 April 1948

Project SIGN was the first official U.S. Air Force investigation into unidentified flying objects. It was formally activated on 26 January 1948 following a directive issued by General L.C. Craigie on 30 December 1947 under the subject heading “Flying Discs.” This document is the initial progress report on the project, prepared by Headquarters Air Materiel Command at Wright-Patterson Air Force Base and signed by Colonel H.M. McCoy, Chief of Intelligence.

The report consolidates more than 100 incidents recorded between April 1946 and January 1948 across numerous U.S. states and several international locations. Recurring characteristics noted across the cases included high rates of climb, the ability to hover motionless, oval or disc-shaped objects, associated sound in some instances, widely varying sizes, exhaust trails, and speeds ranging from stationary to supersonic.

Among the incidents catalogued, several stand out. The Rhodes photographic case (Incident #40) involved photographs that AMC assessed as genuine and not attributable to film or processing defects. A significant cluster occurred at Godman Field, Kentucky on 7 January 1948 (Incidents #33 through #33g), involving multiple independent observers including a Kentucky State Police colonel. The report also records the death of National Guard pilot Captain Thomas Mantell on the same day while pursuing a large metallic object to high altitude.

The document reflects two parallel analytical approaches. Externally, AMC consulted Dr. Irving Langmuir at General Electric, who viewed the data as insufficient for positive identification. Internally, however, the command assessed that a low-aspect-ratio aircraft employing boundary layer control could potentially
replicate many of the reported performance characteristics. As enclosures, the
report attached installments of British aviation engineer A.R. Weyl’s series
“The Biology of the Flying Saucer.”

 

2B. DOW-UAP-D094 – Analysis of Flying Object Incidents in the U.S.,
10 December 1948

This TOP SECRET joint Air Force–Navy intelligence study (Air Intelligence Division Study No. 203) examined approximately 210 reported incidents and concluded that some type of flying object had been observed, though its identification and origin remained indiscernible. The study noted a clear geographic concentration of sightings along the Atlantic and Pacific coasts and in the central states of Ohio and Kentucky, with notable clustering near U.S. atomic energy installations.

The primary analytical hypothesis advanced in the document centres on possible Soviet exploitation of advanced German flying-wing technology. It identifies Dr. Guenther Bock, who had headed Germany’s low-aspect-ratio flying-wing program during the war, as having been taken to the Soviet Union after 1945 and placed in a senior research position. The study references intelligence indicating Soviet plans to build a large fleet of Horten flying-wing aircraft and the possible stationing of Horten XIII jet night fighters near Irkutsk to protect an atomic energy site. It outlines four potential Soviet rationales for operating such craft over U.S. territory: negating American confidence in the atomic bomb as a decisive weapon, photographic reconnaissance of atomic installations, testing U.S. air defences, and conducting familiarisation flights.

 

2C. DOE-UAP-D004 – Conference on Aerial Phenomena, Los Alamos, 16 February 1949

This Secret-classified transcript records a conference held at Los Alamos Scientific Laboratory on 16 February 1949. Participants included Dr. Norris Bradbury, Dr. Edward Teller, future Nobel laureate Dr. Frederick Reines, Dr. Lincoln LaPaz, and representatives from the 4th Army, Armed Forces Special Weapons Project, FBI, and Atomic Energy Commission security.

Dr. LaPaz presented a systematic comparison between the green fireballs observed over New Mexico and conventional meteorite falls, highlighting characteristics he considered incompatible with known meteoritic behaviour, including nearly horizontal flight paths at 8–10 miles altitude, essentially constant velocity, a
distinctive yellow-green colour never previously recorded in meteors, and a
complete absence of sound.

Dr. Edward Teller conducted a technical analysis, estimating light output, kinetic energy, and shock wave implications. He concluded that if both visual and acoustic evidence were accepted, the object could be either a material body or an electron phenomenon, and that the absence of a sonic boom at reported speeds implied a very small physical size unless the luminosity was chemical in origin.

A significant institutional disclosure occurred during the conference: it was stated that Project SIGN had become Project GRUDGE, and that the green fireball events had been formally incorporated into the successor investigation. This establishes direct continuity across the three historical documents in this release.

 

3. New Military Sensor Videos

The fourth tranche includes several new infrared sensor videos of unresolved UAP incidents from different locations and time periods. The most detailed is DOW-UAP-PR115 – Unresolved UAP Report, Gulf of America, 2019. This eight-second infrared sensor video was recorded from a U.S. military platform on 1 January 2019. The footage shows a small dark object of contrast near the centre of the sensor field-of-view. The sensor zooms and pans to track the object as it flickers visually in the display. An AARO comment notes that infrared sensor systems can cause objects to appear to flicker or blend into the background due to auto-gain control filters when the target temperature is similar to the surrounding environment. 

Additional unresolved video reports cover incidents in the Yellow
Sea (2025), East China Sea (2025), and Western United States (1996).
These show areas of contrast being tracked by military infrared sensors, with
some footage presented in frame-by-frame or slow-motion formats.

 

4. NASA-UAP-D030, D031, D032 – STS-80 Unidentified Object Images,
1996

These three still photographs were captured during the STS-80 Space Shuttle mission. They show a small, bright unidentified object in low-Earth orbit near the limb of the Earth, documented across a short sequence from the shuttle viewport.

 

5. Context Within the PURSUE Program

This fourth tranche continues the rolling release of records under President Trump’s 19 February 2026 directive. It follows the first tranche released on 8 May 2026, the second tranche released on 22 May 2026, and the third tranche released on 12 June 2026. As reported in our earlier cables covering those releases, prior tranches included extensive historical FBI and military records, multiple sensor videos, a senior intelligence officer’s first-person account of a 2025 helicopter encounter with orbs, and FBI investigative files on orb sightings. All material across the four tranches remains classified as unresolved.

 

Conclusion

The fourth tranche provides a continuous primary source record of U.S. government UAP investigation from the establishment of Project SIGN in early 1948 through a joint Top Secret intelligence assessment to a classified scientific conference at Los Alamos in February 1949. Across more than 300 combined incident reports, multiple technical analyses, and formal inter-agency assessments, no definitive identification of the observed phenomena was reached. The release of these documents as a coordinated series, together with additional modern sensor and orbital imagery, represents a substantive contribution to the public record on the early institutional handling of UAP.