As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
INTERNAL COMPONENTS OF THE NR SENSOR DEBONDED AND EXTRUDED FROM THE SENSOR HSG. THE EXTRUDED PARTS THEN CONTACTED THE ROTATING COG WHEEL OF THE MAIN ROTOR MAST SYS, DAMAGING THE SENSOR, THE ROTATING COG WHEEL ALSO SUSTAINED DAMAGE DUE TO CONTACT AND CAUSED POSSIBLE CONTAMINATION OF THE MAIN ROTOR GEARBOX OIL WITH PARTICULATES FROM BOTH. THE NR SENSOR AND COG WHEEL.