MaxNg,
Isn't a free turbine where N1 is the gas generator speed? In that case the generator speed (N2) could be less than the rotor rpm% (Nr) while the power turbine (N2) could be in mesh with (same % as) Nr. Put it this way--if there is no load on the power turbine and there are gasses still being pushed through it, then the power turbine would accelerate until a load (the MR) was applied (or until the turbine blades were at zero local angle of attack with the gasses) and N2 would be the same as Nr. Even in this case where N1 is much less than Nr, the power turbine may apply a small torque to the rotor system. So even if you're at flight idle, the Nr and N2 needles could be matched in theory, right? I think this is the difference between real EOLs and practice autorotations that was being discussed.
Edited for clarity.
[ 05 December 2001: Message edited by: Kyrilian ]