Originally Posted by
500 Fan
...The tail rotor is a newer component that will need to be worked on. Apparently it isn’t being employed to reduce tail rotor noise but enhance authority instead and will run at standard rpms. MD were looking at a 530F four blade tail rotor back in the Lynn Tilton days but I am not sure it made it off the drawing board. This could be a development of that TR design...
The option of 4 bladed tail rotor on 500s has been around for many years. I first came across one in the late 80's. But looking up Wikipedia I was surprised by how long ago that option had already been available:
"During 1976, the improved Hughes 500D became the primary model. It was outfitted with a more powerful engine, a T-tail, and a new five-blade main rotor; furthermore, a four-blade tail rotor could be optionally installed".