Willow Run, also known as Air Force Plant 31, was a manufacturing complex in Michigan, United States, located between Ypsilanti Township and Belleville, built by the Ford Motor Company to manufacture aircraft, especially the B-24 Liberator heavy bomber. Construction of the Willow Run Bomber Plant began in 1940 and was completed in 1942. Defense plant The plant began production in summer 1941; the dedication plaque is dated June 16. The plant initially built components. The aircraft manufacturer Douglas Aircraft, and the B-24's designer, Consolidated Aircraft, assembled the finished airplane. Remote assembly proved problematic, however, and by October 1941 Ford received permission to produce complete Liberators. Willow Run's Liberator assembly line ran until May 1945, building almost half of all the Liberators produced. military draft each month 8,200 workers drafted into military service school the Aircraft Apprentice School had up to 8,000 students per week completed training and reported for work dimensions More than 3,200 feet long and 1,279 feet across at its widest point subassemblies parts production and subassemblies at almost 1,000 Ford factories and independent suppliers Airport Willow Run Airport was built as part of the bomber plant. The airfield passed into civilian hands after the war and is now controlled by Wayne County Airport Authority. Part of the airport complex operated at various times as a research facility affiliated with the University of Michigan, and as a secondary United States Air Force Installation. Willow Run Airport has remained active as a cargo and general aviation airfield. Since 1992, it has been home to the Yankee Air Museum. Postwar Ford built the factory and sold it to the government, then leased it back for the duration of the war. When Ford declined to purchase the facility after the war, Kaiser-Frazer Corporation gained ownership, and in 1953 Ford's rival General Motors took ownership and operated the factory as Willow Run Transmission until 2010. Willow Run Assembly operated from 1959 to 1992 on a parcel to the south of the airport. The Fisher Body division also operated at Willow Run Assembly until its operations were assumed by the GM Assembly Division in the 1970s. In 2009, General Motors announced that it would shut down all operations at the GM Powertrain plant and engineering center in the coming year. Since the 2010 closure of Willow Run Transmission, the factory complex has been managed by the RACER Trust, which controls the properties of