This is why I no longer go to air shows - at our local airport - I was well away from that flying rotor.

Canadian Sea king crash - YouTube

That Reno crash - makes you wonder if all the mods made were well engineered for the stresses imposed if indeed it was a tab or aileron failure as suspected. I did read on report that said maybe an engine or other mech failure, the pilot pulled up, lost consciousness from g forces, and the plane augered in due to low and unrecoverable altitude