DOW UAP-D097 — Project Sign Progress Report, 1948
Dr. Voss's Analysis
DOW-UAP-D097 is a 1948 progress report from Project Sign — the U.S. Air Force's first systematic investigation of unidentified flying objects, established December 30, 1947, in response to the wave of sightings beginning with Kenneth Arnold's June 1947 report. Project Sign famously produced an 'Estimate of the Situation' that concluded some UFOs might be extraterrestrial in origin — a conclusion reportedly rejected by Air Force Chief of Staff General Hoyt Vandenberg and ordered destroyed, though some copies are believed to have survived. Project Sign was renamed Project Grudge in February 1949. The visible page of D097 includes a photograph of a large delta-winged aircraft prototype marked 'Confidential,' which may represent an attempt to identify or rule out known experimental aircraft as explanations for some sighting reports — a standard methodology in the Project Sign investigation. This is the earliest-dated formal military UAP investigation document released in the PURSUE program.
Overview
A declassified 1948 Project Sign progress report from the U.S. Air Force, marked confidential, containing a photograph of a large delta-winged aircraft prototype. Published as DOW-UAP-D097 in PURSUE Release 04. Project Sign was the Air Force's first formal UFO investigation program, running from 1947 to 1949.
Key Facts
- ◆1948 Project Sign progress report — the Air Force's first formal UFO investigation program
- ◆Contains a photograph of a large, delta-winged aircraft prototype marked 'Confidential'
- ◆Project Sign ran from December 1947 to February 1949, when it was renamed Project Grudge
- ◆Project Sign reportedly produced an 'Estimate of the Situation' suggesting possible extraterrestrial origin
- ◆Published as DOW-UAP-D097 in PURSUE Release 04 (July 10, 2026)
- ◆Earliest-dated formal military UAP investigation document in the PURSUE program
What Remains Unresolved
- ?Does this progress report reference or reproduce any portion of the 'Estimate of the Situation'?
- ?What specific incidents does this 1948 progress report cover?
- ?Was the delta-winged aircraft referenced as an explanation for specific sightings or as a comparison baseline?
- ?Do any surviving copies of the destroyed Project Sign 'Estimate of the Situation' appear in the broader PURSUE archive?
