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.”
2 3 APir 1948 over 10 9 •.. AMC Subject, Project "SIG!i" e. »umber of objects per aighting, Objects per sighting l 2-6 6-10 Number of eightioga 77 21 8 t. Exhaust traile were reported 23 times. g. Speed has been eetime.ted throughout the entire range from very alow or hovering to supersonio. 6. Incloaures 2 and 5 are anlargementa of photographt taken of Incident f40o Inoloaure 4 1s an evaluation of inolosure 2 by thie Headquarters. Attention 1s iovited to the marked aimilarity between incloaurea 2 ands. and inoloaure 6. Similarity also exiata between inclosures 2 and 3 and oonfigur&tiona illustre.ted in inolosure 6. 7. Representatives from tbie Headquartere visited Dr. Ining Langmuir of the P~sea.rch Laboratories. General Electric Comp&ny. Schenectady, N. Y. to discuss Project "SIGN". It was the opinion of this acienti st that prosent a.vai l!I. ble data does not encompass suffi ci ent information to enable a positive identific~tion to be ma.deo Dr. :.a.n&muir was relucts.nt to consider the so-called "flying discsM as a reality. However, it io be'lieved at this neadquarters that it is possible to oonstruot a low aspeot ratio airoraft that would d~pli oate many of the appearance and performance oharaoteriatics of reported "flyint discs~. Experts have agreed that thie would be possible through the intelligent application of boun:lary layer control. FOR THE COMMANDING GENERAL: ~Me~ 6 Inols H. M. ticC~!1. Jl. Tabulation Co lone1. US&F 2. Photo Chief ot Intelli gence 3. Photo 4. Eval of Incl 2 6. Horten Parabola 6. Biology of I'lying Se.ucor 2 ~ 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.