The MD Helicopters MD 500 series is anamerican family of light utility civilian and military helicopters. The MD 500 originated as the Hughes 500, a civilian version of the US Army’s OH-6A Cayuse/Loach.
The improved Hughes 500D became the primary model in 1976, with a more powerful engine, a T-tail, and new five-blade main rotor; a four-blade tail rotor was optional.The 500D was replaced by the 500E from 1982 with a pointed nose and various interior improvements such as greater head and leg room. The 530F was a more powerful version of the 500E optimised for hot and high work.
McDonnell Douglas acquired Hughes Helicopters in January 1984, and from August 1985 the 500 series were built as the MD 500 series.