NARA RG18: Army Air Forces Flying Disc Investigation - Twining Letter and Project Sign Genesis (1947)
Date
August - December 1947
Document Type
Gov. Investigation Report
Authentication
VerifiedRedaction Status
▐ Partially RedactedIssuing Authority
Headquarters Army Air Forces / Air Materiel Command, Wright Field, Dayton, Ohio
Summary
A collection of foundational Army Air Forces (AAF) flying disc investigation documents spanning August through December 1947, filed under NARA Record Group 18 (Records of the Army Air Forces). The collection includes the September 23, 1947 Twining Letter - officially titled "AMC Opinion Concerning Flying Discs" - in which Commanding General Nathan Twining formally stated "the phenomenon reported is something real and not visionary or fictitious," describing objects "probably approximating the shape of a disc" with "extreme rates of climb, maneuverability" and "evasive" behavior when approached. Also included is Lt. Col. George Garrett's August 22, 1947 Air Intelligence Requirements Division memo establishing common patterns across sightings (metallic surface, no trail, 300+ knot level flight speeds, disc or elliptical shape, normally no sound), and the December 30, 1947 HQ AAF letter directly ordering AMC to establish a formal collection project - the organizational directive that created what became Project Sign. Declassification authority NND 700188. Released via PURSUE Release 1, February 25, 2026.
Significance
Contains the Twining Letter - the single most consequential document in the history of official U.S. UAP investigation. General Twining's September 23, 1947 opinion that flying disc phenomena are 'something real and not visionary or fictitious,' combined with the AAF's December 30, 1947 directive to AMC to establish a formal collection project, are the direct organizational genesis of Project Sign (which began January 1948) and by succession Projects Grudge and Blue Book. The Lt. Col. Garrett memo of August 22, 1947 establishes that pattern recognition and common characteristics analysis that led to Twining's opinion had already been conducted before September 1947. Together these documents establish that the institutionalization of U.S. government UAP investigation was driven by senior military leadership conclusions from the earliest weeks of the modern UFO era.