Project Sign Progress Report, 1948

This is the opening report of Project Sign, the Air Force’s first formal UFO investigation, sent by the Air Materiel Command at Wright-Patterson Air Force Base to Air Force intelligence in April 1948. It is signed for the commanding general by Colonel H. M. McCoy, the command’s chief of intelligence, and promises quarterly reports to follow.

What the first report says

The cover letter traces the project to a Headquarters letter of 30 December 1947 signed by General L. C. Craigie; a technical project was activated on 26 January 1948 and instructions issued on 11 February. Investigators had already checked the schedules of lighted advertising blimps that flew at night as a possible source of reports.

Reviewing the cases, the letter lists recurring features: fast climbs, apparent hovering, oval or saucer shapes, sounds in some reports and exhaust trails in others, and estimated sizes and speeds spread across an enormous range. AMC staff visited the chemist Irving Langmuir at General Electric’s laboratory in Schenectady, who said the data were too thin to identify anything and was reluctant to treat the discs as real. AMC itself thought a low-aspect-ratio aircraft using boundary-layer control could reproduce much of what witnesses described.

The table and the enclosures

The attached tabulation covers reports through 1 February 1948, starting with July 1947 incidents at Muroc Air Field and Portland, Oregon. It includes several entries for 7 January 1948 at Godman Field, Kentucky, the date of the Mantell incident, in which a pilot sent after an object reported there crashed and died. Enclosures include photographs, an illustration labeled “Horten Parabola” and the article from The Aeroplane mentioned in the official description.