Air Materiel Command (AMC) was the Army Air Forces' and then the US Air Force's command for research and development, procurement, supply and depot maintenance from 1946 to 1961. It was headquartered at Wright Field near Dayton, Ohio, which merged with neighboring Patterson Field in January 1948 to become Wright-Patterson Air Force Base. In UFO history its commander signed the 1947 letter calling flying discs "something real," and its intelligence division ran the Air Force's first UFO project.

The command took its name on March 9, 1946, when the Air Technical Service Command was redesignated. Its lineage ran back to a July 1944 merger of the Army Air Forces' supply and engineering commands. Its T-2 intelligence section, inherited from the wartime commands, studied the captured German aircraft that Colonel Harold Watson's teams sent home from Europe at the end of the war to Wright Field and Freeman Field, Indiana. Research and development was split off into the new Air Research and Development Command in 1950, and on April 1, 1961, AMC was redesignated Air Force Logistics Command. That command was inactivated in 1992, when it and Air Force Systems Command were combined into Air Force Materiel Command, still headquartered at Wright-Patterson.

In the summer of 1947, Army Air Forces intelligence asked for the command's view of the flying-disc reports. On September 23, Lieutenant General Nathan Twining, AMC's commander, replied in a letter headed "AMC Opinion Concerning 'Flying Discs,'" now known as the Twining memo. Drawing on a conference of the command's intelligence and engineering staffs, it judged that "the phenomenon reported is something real and not visionary or fictitious," that the objects were probably disc-shaped and about as large as man-made aircraft, and that some incidents might be natural phenomena such as meteors. It weighed a secret domestic project or a foreign power as possible sources, noted the lack of crash-recovered physical evidence, and recommended a classified study with its own priority and code name.

A December 30, 1947 letter from Major General L. C. Craigie gave AMC that study as Project Sign, with a 2-A priority, run by the command's Technical Intelligence Division at Wright Field. Sign's final report, issued under that division's name in February 1949 and classified secret, recommended continuing the work at a minimal level, and the project was renamed Project Grudge the same month. The command's technical intelligence work, and the UFO files with it, passed to the new Air Technical Intelligence Center in May 1951.

AMC's flying-disc paperwork returned to view in 2026 through the Department of War's PURSUE releases. The first, on May 8, included a 1946–47 Army Air Forces file carrying the "something real" passage, which social-media posts presented as newly uncovered although the Condon report had printed the full letter in 1969. On August 7 the fifth release added a 245-page compilation of 1947–48 Air Materiel Command records showing the command collecting reports and explaining some as balloons or astronomical objects while treating the problem as unresolved. The command's 1947 judgment opened two decades of official Air Force UFO investigation at Wright-Patterson that ended with Project Blue Book in 1969.