The
prototype Beech Model 18 was flown for the first time in 1937. First
acquired by the Army in 1940, eventually over 4,000 were built for the
U.S. Army Air Force and over 1,500 for the U.S. Navy. The C-45
stayed in service in the U.S. Air Force until 1963. Civil Model 18's
remained in production until 1969; a production run of 32 years.