This is probably the wrong thread to add this little story into, but it may have some relevence to any one who drives the Robbie.
The topic reminded me of an overspeed situation that a pilot had in the N.T of Oz around 6 years ago.
Early morning, fat dumb and happy on the way to a job. I hear "oh **** " over the company radio. Not the usual frazeology. Several calls made to said pilot, only to hear a garbled chuckle.
The engine on the R22 rotates a set of belts on a sheave set up. The upper sheave is connected to the drive train and houses the free wheel unit. Just forward of the upper sheave there is a flex plate that allows flexing of the drive shaft as the upper sheave moves away from the lower sheave when the belts are tensioned. Forward of this flex plate the drive shaft goes through another flex plate and then into the gear box. Aft of the upper sheave the drive shaft goes rearward to the tail rotor GB etc.
The yoke that attached the short shaft to this aft flex plate broke. The result of this was a very unsubtle scream from the engine as it oversped. The Main Rotor RPM bled off as the fuselage went in all sorts of directions as the pilot inputed corrections for what he perceived was going wrong.
I often think of this story, trying to picture what the reactions would be. Drooping RPM, screaming engine, exaggerated tail rotor response as the engine drive went directly to the tail rotor.
Have a think about it.
P.S He did a text book auto and put it into a clearing the size of a backyard swimming pool surrounded by sand stone rocks 4 metres tall. .......He was our chief pilot after all.
Cheers.