This is a list of United States Army Air Forces B-24 Liberator combat units during World War II including variants and other historical information. Heavy bomber training organizations primarily under II Bomber Command in the United States and non-combat units are not included. The USAAF took delivery of its first B-24As in June 1941, although the B-24D was the first production model delivered in quantity in July 1942. B-24s were assigned to every combat Air Force; at peak inventory, the USAAF had 6,043 B-24 Liberators operating worldwide in September 1944. Following the end of World War II, the Liberator was rapidly withdrawn from USAAF service, being replaced by the Boeing B-29 Superfortress. Literally thousands of Liberators were flown to various disposal units where they were cut up for scrap. Some brand-new late-production B-24Ms from Convair/San Diego and Ford/Willow Run were flown directly from the factory to various reclamation sites such as the scrapyard at RFC Kingman, Arizona in 1945, as the war in Europe had ended and B-29s were doing most of the long-range bombing work in the Pacific. Only a few Liberators were still around when the United States Air Force was formed in 1947, most of them being used for various research purposes. The last USAF Liberator, a Ford EZB-24M-20-FO serial number 44-51228 used by the Aeronautical Icing Research Laboratory for ice research, was struck off the rolls in 1953. For a time, it was on display at Lackland AFB, Texas, with the armament and gunner positions restored. It is currently at the American Museum at Duxford Aerodrome, England painted as 44-50492, a B-24M that was assigned to the 392d Bombardment Group, 578th Bombardment Squadron. Combat Organizations Army Air Forces Antisubmarine Command Established in October 1942 to deal with the U-boat threat; formed largely from the resources of I Bomber Command. Inactivated in August 1943 when antisubmarine mission was taken over by the United States Navy. 1st Search Attack Group October 1942–August 1943; Langley Field, Virginia 2d Search Attack Squadron 3d Search Attack Squadron 4th Search Attack Squadron Became radar training unit for USAAF, inactivated April 1944 304th Bombardment Group October–December 1942Langley Field, Virginia Its Bombardment Squadrons were redesignated as Antisubmarine Squadrons serving in the USA with the 25th & 26 th Wings. The 19th ARON went to the UK when the 479th AG was activated 1st Antisubmarine Squadron 18th Antisubmarine Squadron 19th Antisubmarine Squadron 26th Antisubmarine Wing