Estimate of the Situation
The Estimate of the Situation was a document supposedly written in 1948 by the personnel of United States Air Force's Project Sign -including the project's director, Captain Robert R. Sneider - which explained their reasons for concluding that the extraterrestrial hypothesis was the best explanation for unidentified flying objects.
As late as 1960, USAF personnel claimed that the document never existed. However, several Air Force officers, and one consultant, describe the report as being a real document that was suppressed. Jenny Randles and Peter Hough describe the Estimate as the "Holy Grail of ufology" and note that Freedom of Information Act requests for the document have been fruitless.
Project Sign was established in late 1947, and was charged with investigating "flying saucer" reports. In line with orders from high-ranking USAF officers, Sign's personnel operated on the principle that the subject should be taken seriously, on the grounds that UFOs may represent genuine aircraft whose origins are mysterious and possibly threatening to US security.
 Chiles-Whitted Encounter
Though Sign investigated earlier UFO reports, Historian David Michael Jacobs writes that the highly-publicized Chiles-Whitted UFO Encounter of July 24, 1948 "had a great impact at Sign". In that encounter, two experienced airline pilots claimed a torpedo-shaped object nearly collided with their commercial airplane. Sign personnel judged the report convincing and compelling, partly because the alleged object also closely matched the description of an independent sighting from The Hague a few days earlier.
According to Michael D. Swords, Sign personnel "intensely investigated" the Chiles-Whitted for several months. Despite the lack of physical evidence, some Sign personnel judged this and other UFO reports quite persuasive, and concluded that UFOs could have only a non-earthly source. Swords writes,
- "The project members reasoned that they had several dozen aerial observations that they could not explain, many of them by military pilots and scientists. The objects seemed to act like real technology, but their sources said they were not ours. The flying fuselage encounter [Chiles-Whitted] intrigued them. The Prandtl theory of lift indicated that such an odd shape can fly, but it would need some form of power plant advanced well beyond what we could build (e.g., nuclear)." (Swords, p.93; emphasis in original)
Given that there was no evidence that either the U.S. or the U.S.S.R. had anything remotely like the UFOs reported, Sign personnel gradually began considering extraterrestrial origins for the objects.
Swords argues that this consideration of non-earthly origin was "not as incredible in intelligence circles as one might think." Because many in the military were "pilots, engineers and technical people" they had a "'can do' attitude" and tended to regard unavailable technologies not as impossibilities, but as challenges to be overcome. Rather than dismissing UFO reports out of hand, they considered how such objects might function. This perspective, argues Swords, "contrasted markedly with many scientists' characterizations of such concepts as impossible, unthinkable or absurd."
 Writing, submission and evaluation
According to Swords, the Estimate was probably completed in September 1948. The Estimate also argued that UFO reports might closely coincide with the approach of the planets Mercury, Venus or Mars to Earth, that the UFOs might be using the planets as launching bases, and predicted a wave of UFO reports in mid-October.
In late September or early October, 1948, the Estimate was approved by Colonels William Clingerman and Howard McCoy (Sneider's superiors), who then submitted it to the office of General Charles Cabell, the chief of Air Force intelligence.
According to Swords, The Pentagon went into an "uproar" over the Estimate, which generated "intense" debate. Cabell was newly-appointed, and found himself in charge of a "split house": some were sympathetic and intrigued, if not entirely convinced of the Estimate's accuracy, while others rejected the very idea of interplanetary saucers as impossible. Unsure of how to proceed, Cabell eventually submitted the Estimate to his superior, General Hoyt Vandenberg, Chief-of-Staff of the U.S. Air Force.
According to Ruppelt, the Estimate was rejected by Vandenberg primarily due to lack of supporting physical evidence, and was "batted back down" the chain of command.
In a letter dated November 3, 1948, Cabell wrote to Sign, via McCoy, describing flying saucers as real, but rejecting the interplanetary hypothesis and asking for another Estimate. Cabell wrote:
- The conclusion appears inescapable that some type of flying object has been observed. Identification and the origin of these objects is not discernible to this Headquarters. It is imperative, therefore, that efforts to determine whether these objects are of domestic or foreign origin must be increased until conclusive evidence is obtained. The needs of national defense require such evidence in order that appropriate countermeasures may be taken.
McCoy responded in a somewhat defensive letter dated November 8, 1948. He noted that many of the UFO reports were misidentified everyday phenomena (see Identified flying object), but also restated the rejected ideas of the Estimate without explicitly endorsing the interplanetary hypothesis; as Swords writes," [Project Sign] just had their knuckles rapped, so they defended themselves."  McCoy wrote,
- ...there remains a certain number of reports for which no reasonable everyday explanation is available. So far, no physical evidence of the existence of the unidentified sightings has been obtained...
- The possibility that the reported objects are vehicles from another planet has not been ignored. However, tangible evidence to support conclusions about such a possibility are completely lacking...
When Sign personnel refused to abandon the interplanetary hypothesis, many were reassigned, and Sign was renamed Project Grudge in 1949. According to Ruppelt, "The Estimate died a quick death. Some months later it was completely declassified and relegated to the incinerator. A few copies, one of which I saw, were kept as mementos of the golden days of the UFOs."
The first public report of the Estimate was in Captain Edward J. Ruppelt's 1956 book, The Report on Unidentified Flying Objects. He wrote:
- In intelligence, if you have something to say about some vital problem you write a report that is known as an "Estimate of the Situation." A few days after the DC-3 was buzzed [the Chiles-Whitted UFO report], the people at ATIC decided that the time had arrived to make an Estimate of the Situation. The situation was the UFOs; the estimate was that they were interplanetary!
- It was a rather thick document with a black cover and it was printed on legal sized paper. Stamped across the front were the words TOP SECRET.
- It contained the Air Force's analysis of many of the [UFO] incidents I have told you about plus many similar ones. All of them had come from scientists, pilots, and other equally credible observers, and each one was an unknown ...
- ... When the estimate was completed, typed, and approved, it started up through channels to higher command echelons. It drew considerable comment but no one stopped it on its way up.
Clark notes that "No copies of this near-legendary document have surfaced since."
 Denial of existence
Ruppelt's 1956 book, which first publicly disclosed the Estimate, was cleared by the Air Force. Clark writes (Clark, 1998), that as late as 1960, Air Force officials denied that the Estimate was real, despite the fact that censors had approved Ruppelt's book a few years before. According to Clark, the U.S. Air Force later formally admitted the Estimate was real, but Clark's bibliography does not make clear what statement or document confirmed the Estimate's reality.
Additionally, according to Clark, the Estimate's existence was confirmed by U.S. Air Force Major Dewey J. Fournet, who as an Air Force major in the Pentagon served as liaison with official UFO project headquartered at Wright-Patterson Air Force Base in Dayton, Ohio. Fournet has been described  as being "unimpressed" with the Estimate, and was furthermore quoted as describing the ET conclusion as an "extreme extrapolation" based on scant evidence.
 Roswell UFO incident
In the early 1980s, researcher Kevin D. Randle said he spoke with an unnamed colonel who claimed to have helped write the Estimate when he was a lieutenant. According to the colonel, when Vandenberg was sent a working draft of the report, he allegedly ordered the paragraphs giving physical evidence (metal recovered in New Mexico) removed from the report. After doing so, Vandenberg then rejected the final version as lacking physical evidence. Randle claimed that he realized the significance of this anecdote only a few years later, while investigating the 1947 Roswell, New Mexico crash. According to Randle, the colonel had died by that point, and a follow-up interview was not possible.
The McCoy letter of November 8, 1948, which mentioned that there was no physical evidence of extraterrestrial origins for flying saucers, has sometimes been cited as evidence against the Roswell UFO incident of July, 1947, where a UFO allegedly crashed in the New Mexico desert. Swords argues that the McCoy letter should not be interpreted this way, because the U.S. Military usually operates in a highly compartmentalized, need to know basis. If something as extraordinary as an alien spacecraft had crashed in the summer of 1947, Swords contends that fact would have almost certainly been quickly suppressed, and that Sign would not necessarily have been informed of it.
- The term "estimate of the situation" is generic, often used in military intelligence to describe a type of early report on an important subject.
- see Clark, 1998
- Randles and Hough, p85
- Jacobs, 47
- Swords, p93
- Cabell Memo To AMC - 3 NOV 1948
- McCoy Memo - 1948
- "unknowns" defined by Ruppelt as well-documented UFO reports from reliable observers which defied analysis
- Clark, 1998
- Clark, 178
- PROJECT 1947 - UFOS: GOVERNMENT INVOLVEMENT, SECRECY, AND DOCUMENTS
- Hynek, 1973
- Randle, 1989
- Jerome Clark; The UFO Book: Encyclopedia of the Extraterrestrial; Visible Ink, 1998; ISBN 1-57859-029-9
- Richard M. Dolan, UFOs and the National Security State: Chronology of a Cover-up 1941–1973, 2002, ISBN 1-57174-317-0
- David Michael Jacobs; The UFO Controversy In America; Indiana University Press, 1975; ISBN 0-253-19006-1
- Diana Palmer Hoyt, "UFOCRITIQUE: UFO's, Social Intelligence and the Condon Committee"; Master's Thesis, Virginia Polytechnic Institute, 2000; read it online
- J. Allen Hynek; The UFO Experience: A Scientific Inquiry; 1972; Henry Regnery Company
- Kevin Randle; UFO Casebook; Warner Books; 1989; ISBN 0-446-35715-4
- Jenny Randles and Peter Houghe; The Complete Book of UFOs: An Investigation into Alien Contact and Encounters; Sterling Publishing Co, Inc, 1994; ISBN 0-8069-8132-6
- Edward J. Ruppelt; The Report on Unidentified Flying Objects; 1956; Doubleday & Company online--see Chapter 2
- Michael D. Swords, "UFOs, the Military, and the Early Cold War" (pp. 82–122 in UFOs and Abductions: Challenging the Borders of Knowledge, David M. Jacobs, editor; University Press of Kansas, 2000; ISBN)
- Michael D. Swords, "Project Sign and the Estimate of the Situation" (2000) read it online