I need the Eurocopter EC135's rotor speed to estimate its natural frequencies. I checked the helicopter TCDS but I only find there percentage values. For example for the P1 variant: 104% Max and 95% Min. This is percentage of what? In other helicopters I normally get concrete values in RPM.
The main rotor speed (100%) of the EC-135 is 395 RPM.
I don't have an exact answer for the EC135, but in most helis, its somewhere arond 400RPM. Remember that the tips of the rotors cannot go supersonic, so its dependent on rotor diameter