Fairchild Duramold and then used on the AT-21 Gunner trainer. Before the outbreak of the war, Fairchild realized the large sales potential for trainers and developed the Model 62(M-62), which met the requirements for both military and civilian flying schools. In the summer of 1939, he entered the plane in a U.S. Army competition against other primary trainer candidates. When the M-62 won the contest, the Air Corps awarded Fairchild with a contract for 270 planes to be designated the PT-19. The PT-19 model, was the main product of the Fairchild plant in Hagerstown. In 1942, Fairchild developed the Fairchild Model 78, which was designed specifically for military transport. He was awarded a military contract to build his large-capacity twin-boom plane, which featured a hinged rear door used to load bulky cargo to be designated the C-82 Packet. It was nicknamed the "Flying Boxcar" because the plane's cargo capacity of was the same as that of a standard railway boxcar. It was used after World War II to fly assembled vehicles into Berlin. Fairchild was able to remain profitable after the war by manufacturing the C-119 Flying Boxcar, an upgraded version of the Packet which incorporated more powerful engines and greater capacity. From December 1949 until 1955 over 1,100 C-119s were constructed. This was the last Fairchild design to be mass-produced. The C-119 was eventually converted into the AC-119, a night attack gunship used in the Vietnam War. In the 1950s, Fairchild manufactured the C-123 Provider, a short-range assault transport which was used for a variety of purposes, including spraying defoliants in Vietnam. In 1956, Fairchild built the Fokker F-27 Friendship passenger airplane, the first American-built airliner in service. Fokker licensed the design to Fairchild so it could be made in the US; Fairchild also made a stretched version of this aircraft called the FH-227. The 40-seat plane was also the first to offer its passengers air conditioning and pressurization within the short-haul marketplace. It became widely used as a "feeder" plane for commercial carriers across the globe. After acquiring Hiller Helicopters and becoming Fairchild Hiller in 1964, it introduced the FH-1100 civilian helicopter. On December 18, 1970, the Air Force selected Fairchild to develop the YA-10A prototype, which was the last aircraft project undertaken before Fairchild's death in 1971. Production of the A-10 Thunderbolt II began in 1974. It was nicknamed the "Warthog" because it was built as a