PROJECT SIGN

Opening

In 1948 the US Air Force opened its first formal investigation of flying saucers. It was run from Wright Field in Ohio under General Nathan Twining, head of the Air Materiel Command, who a few months earlier had written that the phenomenon reported was something real. The project was first called Saucer, then Sign. Its job was to collect and evaluate every report and to decide whether the objects were a threat to national security.

Sign lasted about a year. It left behind one of the best-known unproven documents in UFO history: an "Estimate of the Situation" that is said to have concluded the objects were interplanetary, and to have been rejected and destroyed by the Air Force chief of staff. Nobody has ever produced a copy. The story comes from one man's book, and the argument over whether the document existed is older than most of the people having it.

Timeline

September 1947Twining writes the letter that leads to a formal Air Force study of the phenomenon.

Early 1948Project Sign begins, at first under the name Saucer, at Wright Field. In January the Mantell crash is one of its first cases.

Summer 1948Sign handles the Chiles-Whitted encounter in July. In some accounts its staff write the Estimate of the Situation this summer.

Early 1949Sign is replaced by Project Grudge. A report from the Intelligence Division of the Air Materiel Command, publicly released on 27 April 1949, says some of the objects appear to be real aircraft, that there is not enough data to say where others come from, and that almost all cases have ordinary explanations.

30 April and 7 May 1949The Saturday Evening Post publishes a two-part article by Sidney Shalett that backs the ordinary explanations, citing balloons and hoaxers.

May 1949Sign officers visit an abandoned farm at Glen Burnie, Maryland, to examine an inventor's disk-rotor aircraft.

August 1949Grudge issues its only formal report. It attributes the sightings to misidentification, hoaxes, mass hysteria and psychopathology. Project Grudge ends on 27 December 1949.

1956Edward J. Ruppelt publishes The Report on Unidentified Flying Objects and tells the Estimate story.

1966At a congressional hearing, Representative L. Mendel Rivers says no such Estimate ever existed.

Key figures

Nathan Twining commanded the Air Materiel Command and set the project up. Captain Robert R. Sneider is named in several accounts as Sign's director and as one of the authors of the Estimate.

Hoyt Vandenberg, the Air Force chief of staff, is said by Ruppelt to have rejected the Estimate for lack of proof. One account says he ordered the paragraphs describing physical evidence, metal recovered in New Mexico, to be removed from a draft. That claim comes from an unnamed colonel interviewed by the researcher Kevin Randle in the early 1980s.

Edward Ruppelt, who ran the later Project Blue Book, was not at Sign. His 1956 book is the main source for the Estimate.

Jonathan Edward Caldwell was an inventor whose disk-rotor aircraft Sign officers examined.

Physical and documentary trail

The record: the Twining letter, the 1949 Air Materiel Command report, and the Grudge report that followed. They show an Air Force project that took the phenomenon seriously enough to keep records and that later swung toward explaining it away.

What is missing is the Estimate. No copy or corroboration of Ruppelt's claim has been produced, and Air Force officials have denied it ever existed. A few Air Force officers and one consultant have said it was real and suppressed. Popular Mechanics called it "probably more mythological than real". The date given for the 1966 hearing is also inconsistent between sources.

Things you might not know

• It began as Project Saucer. The name was changed to Sign, which sounds more like a code word.
• The Caldwell machine looked like a saucer. Sign officers and Maryland police found the damaged remains of a disk-rotor aircraft on a Glen Burnie farm and interviewed a pilot who had tried to fly it in 1937 or 1938. They concluded it could not explain the saucer reports.
• The photographs had a long afterlife. Later UFO books presented pictures of Caldwell's machine as a crashed saucer, and more recently it has turned up in Nazi saucer stories.
• Grudge's conclusion was about fear. It argued that reports could be exploited by a foreign power to cause panic, so they were a military problem.
• Grudge's own critics were inside. Ruppelt and J. Allen Hynek called it far from an objective scientific examination.

Competing explanations

The Estimate existed and was suppressed. Ruppelt said so, a handful of officers agreed, and the Air Force's move from Sign to Grudge fits a change of line. The weakness is that no copy has surfaced in seventy years, and the main source is a single author writing from memory.

The Estimate was a rumour or a draft. Sign staff may have discussed an interplanetary reading, and a draft may have circulated that was later dropped. That would explain the story without a destroyed report.

It never existed. This is the Air Force's position. It has not been proved, but the lack of any documentary trace points that way.

Later life of the case

Sign became the opening chapter of the Blue Book story, told in the Project Blue Book report, and its leading cases include Mantell and Chiles-Whitted. The Estimate has been cited by researchers and disclosure advocates ever since as an example of a possible suppressed finding.

Finding

Project Sign was real, it was a serious effort, and it ended when the Air Force changed course. That much is documented. Whether it reached an extraterrestrial conclusion that was rejected is an open claim resting on one book.

What still will not resolve: whether the Estimate of the Situation existed in any form, and whether a copy survives in an archive nobody has searched.