Project Sign

The project was established in 1948 by Air Force General Nathan Farragut Twining, head of the Air Technical Service Command, and was initially named Project SAUCER.[1] The goal of the project was to collect, evaluate, and distribute within the government all information relating to UFO sightings, on the premise that they might represent a national security concern.[1]

At first the project hypothesized the sightings might be Soviet secret weapons.[1] However, Project Sign's final report, published in early 1949, stated that while some UFOs appeared to represent actual aircraft, there was not enough data to determine their origin.[2] Almost all cases were explained by ordinary causes, but the report recommended a continuation of the investigation of all sightings.[1]

Project Sign was first described in the 1956 book The Report on Unidentified Flying Objects by retired Air Force Captain Edward J. Ruppelt who later directed Project Grudge and Project Blue Book. In this he also claimed that Sign had produced an "Estimate of the Situation" which endorsed an interplanetary explanation for UFOs, but General Hoyt Vandenberg, Chief of Staff of the Air Force, shut down Project Sign for lack of proof.[3] No copy of this document or any other corroboration of Ruppelt's claim has been produced, and Popular Mechanics called the report "probably more mythological than real".[4]

Project Sign was followed by Project Grudge after a conclusion was reached that evaluations of UFOs were a necessity of military intelligence in a post-war climate.[5]

• Dolan, Richard M. (2002) UFOs and the National Security State: Chronology of a Cover-up 1941–1973. Hampton Roads Publishing Company, ISBN 1-57174-317-0
• Peebles, Curtis (1994). Watch the Skies! - A Chronicle of the Flying Saucer Myth. Smithsonian, ISBN 1-56098-343-4.

• the Twining letter
• dod.mil (archived)