We had a B model destroy itself on the ground years ago. The star was also destroyed in the process. I flew it on the prior flights away from base on a remote site, and in the pre-flights was noticing a growing tear in a frequency adapter, and degredation of the spherical bearings.
On one landing I got into ground resonance and returned the helicopter to base. I got the usual "I've seen a lot worse" upon reporting the issue, and on the subsequent start up with another pilot the incident occured.
I have flown Astars and Dauphins with dressed or scalloped cracked stars that never gave any trouble or degraded further. How was the condition of the elastomers of that machine?
Also, I once had new heel springs installed where the bolts weren't torqued, and that caused ground resonance.