FB
A lot of helicopters require this but I am trying to find out the aerodynamic reasons why Sikorsky, amongst others, say the rotor system is more efficient at a lower RPM. ie What happens to the lift/drag ratio, why it happens and what else happens that I am unaware of? The Puma is also more efficient at about 250 RPM for presumably the same reason, drooped like your EC135, and if any Aerospatiale/EC people can contribute their explanation I would appreciate it.
Jab