As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) ON AIRCRAFT APPROACH FOR LANDING, AIRFRAME VIBRATION WAS FELT. UPON LANDING AIRCRAFT WAS GROUND ROCKING. REDUCTION OF ENGINE THROTTLES INCREASED GROUND ROCK AND AIRFRAME VIBRATION. THROTTLES SHUT-OFF AND ROTOR BRAKE APPLIED, UPON BRAKING M/R BLADE SWEPT FORWARD. INVESTIGATION FOUND M/R DAMPER PISTON ROD SEVERED AT THREADED PORTION. DAMPER PISTON ROD SENT OUT FOR METALLURGY TESTING.