it does only look like this when spooling up, not when standing still or at full rpm
not sure but i may have seen this in mi8 too
It also appears that you can see the issue in the shadow of the chopper even when moving:
Looks like the wreck rotor somehow found its way into the LOD. I'll see if I can replicate it.
Scratch that the models are fine, looks like the selection for main rotor was incomplete. Testing.