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.”
• flDENllAL e Incident 68 ColOJ' Hot stated Shape I D1eo - appeare~ a tail. to have UU. 30 tt d1aaeter sounc1 lone 69 White lot 1tated Not stated Bussing sound. 70 Not stated Giant til'e cracker Kot stated Bu11DI aound not aa loud aa a rocket Ship. 71 Rot 1t1ted Hot 1t1ted lot atated Not stated 72 Silver Sphere( nt not like 1auoer or diac. 2·3 tt diameter Rot 1tated Deep Gold 1111pt1oal 15 tt long 2·3 tt 1n length. lot atated 74 Bot stated Tapered lbarpely to a point in the tront end. ,o tt. diaaettr Hone 75 Slq blue Oblong like a broad rill hat with a low crown. 20 tt. lona am 10 t,. thiolr. Kade a av1shiq sound. 76 Not stated Jot 1tated Hot stated Lite the eoho ot • aotor. 77 Light colored Only oonerete evidence 50•100 tt lfide. or tora appeared on the lett tangent ot the group. Loud roar 78 Light gray e1rou1ar 8 tt. diueter Bot ■ tated 79 S1lftl' Bot atated Lu•er than a Pibal balloon When obaened through a theodolite. Not atated 80 Retleoted vh1te light. "Blob 11 SMll ail"plane Hone 81 S11Yer ' Large Balloon With silver Large d11c below it, no attaebing cables vere noticed. lot etated 82 Proat7 ltbite Round and tlat Equal to b\11.k ot 6 eaob, B-29 air· planes tdth dia .. •t•r to tluomeas ratio ot 10-1. A 1l1gbt mahing. 83 Black Round 'tVtnt,-.f'ive cent piece. lot atated
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.