Finally! Some hero did the inevitable and mounted a GoPro on the main rotor hub of a helicopter,
and not just any helicopter but a Russian-built Mi-8 Hip.
It gives an incredibly intimate but dizzying view of of the hodgepodge of bolts, plates and actuators that keep a helicopter thumping away through the air.
The Mi-8 has a five-blade fully articulated main rotor with hydraulic lead-lag dampers. You can see these dampers at work minimizing the retreating blade’s “dip.”