Documents / Case file
This is an initial Project Sign progress report dated April 1948, sent from Headquarters, Air Materiel Command at Wright-Patterson Air Force Base to the Chief of Staff, U.S. Air Force. It tabulates about 100 unidentified flying object reports received through February 1948, covering shape, size, number of objects, speed and exhaust trails. Dr. Irving Langmuir found the data insufficient for a positive identification. Headquarters judged that a low aspect ratio aircraft using boundary layer control could reproduce many of the reported characteristics.
From the source: Release of 2026-07-10 Incident: 1948, Various. This file contains an initial report from the Air Materiel Command regarding Project Sign. Project Sign was a 1948-1949 U.S. Air Force program to investigate the nature and origin of unidentified flying objects (UFO). The report details 100 UFO sightings from 1947-1948. The file also contains an article excerpted from “The Aeroplane,” an aviation-focused periodical magazine published between 1911 and 1968, titled “The Biology of the Flying Saucer.”
vbV~r IDENTIAL lnoident No. Color Sha.pc Size Sound 30& Amber Round or oval C-47 airplane Jliono !Ob Bright white to amber Cone-shaped. blunt on top and taper ing orr toward bottom ' Rnonnou• 30c White lligbt) RoWlld Comparable 'to way light run- Bone 31 White Not stated lot stated ltone 52 Amber Mot stated tiot stated !lone 33 Sun flashes on metal or metallic Roughly circular At the distance and lone altitude the object appeared ~o be the size of a11Ter dollar ffll.1te or luminous. ·rurnod to be more red aa the aun aet Round teudi og to be conical Unknown - altitude a.na distance too great Iona ~ot auted Cone. red topped with Jot stated lone :53e Si lver with shadow Raindrop Unlcnown - believed to be lar~ lJnJcnoa 53d 1'h1. te Round at time• cone ~haped - Uneert&in because of distance 53e lfhi.te Round l/4: she full moon lone 33.f l(atallio Bot stated Tremendous SSg "lfot stated Cone 100 ft. high. 43 .rt. acrose !lone Redish tinge Round Large gre.pef'rui t Ion• 35 Fire oolor Ball liot stated llot atatecl 36 )lot stated Bot stated Mot at&.ted Bot stated 38 Reddish with blue background.. Black with white baokground SilTer lot stated Ball S ft. from point of view .Not ate.ted lone Mot stated NND 927545
Case file, from the pursue collection. The PDF is mirrored here; the original link is above. 45 pages are in the text index: search them above, or from the library's search.