In 1970 the 500C followed with a more powerful turboshaft. From 1976 deliveries were of the 500D, an improved version with again a more powerful engine, a T-tail, and new five blade main and optional four blade tail rotors. The 500D was followed by the 500E from 1982 with recontoured nose and various interior improvements including greater head and leg room.
From 1984, when McDonnell Douglas acquired Hughes Helicopters, the Hughes name disappeared and the 500E and 530F were built as the MD-500E and MD-530F Lifter. Military variants are marketed under the MD-500 Defender name.
This add-on represents the 500D line with four variations:
- Military observation
- Military Special Forces attack/support
- Military SOAR personnel transport
- Civil passenger transport