As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CHROME SURFACE ON TAIL ROTOR OUTPUT SHAFT COMPROMISED. SURFACE AREA OF DAMAGE EXCEEDS MFG SPECIFIED LIMITS. PITTING IN THE METAL SUGGESTS THAT CORROSIVE ELEMENTS WERE PRESENT BEFORE THE CHROME PROCESS OCCURRED. THIS CORROSION CAUSED THE CHROME FINISH TO NOT ADHERE PROPERLY AND THE WEAR PRODUCED BY THE TAIL ROTOR SPIDER BEARING CAUSED PREMATURE FAILURE OF THE CHROME SURFACE.