 Perhaps the best known Beech aircraft, the single-engined Bonanza has been manufactured in various models since 1947.The Bonanza has had the longest production run of any airplane, past or present, in the world.Other important Beech aircraft are the King Air and Super King Air line of twin-engined turboprops, in production since 1964, the Baron, a twin-engined variant of the Bonanza, and the Beechcraft Model 18, originally a business transport and commuter airliner from the late 1930s through the 1960s, which remains in active service as a cargo transport.