Declassified in 1997 as part of the GAO's investigation sponsored by
the late Congressman Schift (Rep - New Mexico) in the Roswell
incident, project SIGN began in 1947 as an Air Force
investigation of UFOs, headed by Col. H. M. McCoy, Chief of
Intelligence, Air Materiel Command, Wright Patterson AFB, Dayton
Project SIGN ended in early 1949 when the name was
changed to Project GRUDGE, though Col. McCoy remained
in charge of the successor project. The 900 pages of released
documents are primarily UFO intelligence reports, some with
good data and administrative correspondence, green fireball reports
of 48-49 in the desert southwest. The Fund for UFO Research has an
excellent summary of the Air Force's project SIGN
At approximately 3.00 p.m. on the afternoon of 24 June 1947, pilot
Kenneth Arnold had his now-classic UFO encounter near the
Cascade Mountains, Washington State.
According to Arnold, he viewed
nine, elliptical-shaped objects flying in a wedge-like formation and
stated that the objects flew as a saucer would if it were skimmed
across a pool of water. The Flying Saucer mystery had begun. In the
weeks and months after Arnold’s now-historic encounter, a wealth of
other reports reached both the military and the media.
On 28 June, while flying at a height of 10,000 feet and 30 miles
northwest of Lake Meade, Nevada, an Air Force Lieutenant reported
seeing five or six white, circular-shaped UFOs in close formation
and traveling at a speed of approximately 285 miles per hour. The
following day, a party of three – including two scientists -
reported seeing a large UFO near the White Sands Missile Range.
were able to keep the object in view for almost a full minute and
described it as disk-shaped, moving at high speed and with no
On 7 July 1947, five Portland, Oregon, police officers reported
varying numbers of disks flying over different parts of the city;
and on the same day, William Rhoads of Phoenix, Arizona, saw
an object not dissimilar to that reported by Kenneth Arnold.
Seventy-two hours later, a Mr. Woodruff, a Pan-American
Airways mechanic, reported seeing a circular-shaped UFO flying at
high speed near Harmon Field, Newfoundland.
As the summer of 1947 drew to a close and the Air Force had become an
independent entity of the military, Air Intelligence demanded a
report from Air Materiel Command regarding the then-current opinions
on "flying disks". Lieutenant General Nathan F. Twining, the
Commander of the Air Materiel Command at Wright Field, held a
conference with individuals attached to the Propeller Laboratories
of Engineering Division T-3, the Air Institute of Technology, and
the Office of Chief Engineering Division.
The result was a 23
September 1947, memorandum sent by Twining to Brig. General
George Schulgen, Chief of the Air Intelligence Requirements
It concluded that:
a. The phenomenon
reported is something real and not visionary or fictitious.
b. There are objects probably approximating the shape of a
disk, of such appreciable size as to appear to be as large as
c. There is a possibility that some of the incidents may be
caused by natural phenomena, such as meteors.
d. The reported operating characteristics such as extreme rates
of climb, maneuverability, and actions which must be considered
evasive when sighted or contacted by friendly aircraft and radar,
lend belief to the possibility that some of the objects are
controlled either manually, automatically, or remotely.
e. The apparent common description of the objects is as
(1) Metallic or
(2) Absence of trail, except in a few instances when the object
apparently was operating under high performance conditions
(3) Circular or elliptical in shape, flat on bottom and domed
(4) Several reports of well kept formation flights varying from
three to nine objects.
(5) Normally no associated sound, except in three instances a
substantial rumbling roar was noted.
(6) Level flight speeds normally above 300 knots are estimated.
f. It is possible
within the present U.S. knowledge - provided extensive detailed
development is undertaken - to construct a piloted aircraft which
has the general description of the object in subparagraph (e) above
which would be capable of an approximate range of 7,000 miles at
g. Any development in this country along the lines indicated
would be extremely expensive, time consuming, and at the
considerable expense of current projects and therefore, if directed,
should be set up independently of existing projects.
h. Due consideration must be given to the following:
(1) The possibility
that these objects are of domestic origin - the product of some high
security project not known to AC/AS-2 or this Command.
(2) The lack of physical evidence in the shape of crash
recovered exhibits which would undeniably prove the existence of
(3) The possibility that some foreign nation has a form of
propulsion, possibly nuclear, which is outside of our domestic
As a result, Air Materiel
Command requested that a directive be issued assigning a permanent
project to study the UFO phenomenon.
On 30 December 1947, Major
General L. C. Craigie, Director of Research and Development,
issued an order that would establish Project Sign as
the investigative body tasked with examining UFO reports. It would
be the role of Sign to: “… collect, collate, evaluate and distribute
to interested government agencies and contractors all information
concerning sightings and phenomena in the atmosphere which can be
construed to be of concern to the national security.”
During the first six months of 1948, Project Sign
UFO reports at Wright-Patterson AFB and focused much of its
attention on the possibility that some UFOs were, indeed,
other-worldly in origin.
On 5 August 1948, the Project Sign
determined that it was time for an evaluation of the data obtained. As
a result, a Top Secret Estimate of the Situation was prepared by the
US Air Force’s Air Technical Intelligence Center, which concluded
UFOs were interplanetary spacecraft.
This was to cause
widespread dismay and concern amongst the higher echelons of the
military and the conclusions of the report were rejected, largely on
the orders of Chief of Staff, General Hoyt Vandenberg,
who argued that the Estimate was bereft of any firm evidence to
support such beliefs. As a result of this, the ET-hypothesis
lost favor within Sign; and those involved in the production
of the report were rapidly reassigned alongside rumors of a lack of
morale within the project.
Nevertheless, by the end of 1948, Project Sign had
received several hundred UFO reports, of which 167 had been
classed as “good”; and almost 40 of which were considered to be
“unknown”. By 16 December 1948, however, the work of Sign
(much of which supported the
ET-hypothesis) came to a close; and Brigadier General Donald
Putt changed the name and made way for the more
If the Estimate of the Situation report was rejected by General
Vandenberg, one might ask, is that because the conclusion was
based on faulty data or is there a more sinister scenario?
known that the project only carried a 2A restricted classification
(with 1A being the highest); and whilst the project could, under
required circumstances, be assigned a higher clearance, this
suggests strongly that Sign personnel did not have blanket
need-to-know with respect to the UFO mystery.
the author and investigator Kevin Randle has spoken with a
U.S. colonel who had worked with ATIC in the late 1940s and
who confirmed the existence of the Estimate of the Situation and was
aware that it had been hand-delivered to Vandenberg.
According to the colonel,
Vandenberg ordered that two paragraphs be removed from the
Estimate – both of which referred to UFO crashes in New
Vandenberg’s actions seem to suggest that,
Sign’s conclusions were being manipulated from the very
(b) there were those within the military that wanted
Sign kept strictly out of the crashed UFO/Majestic 12