As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PILOTS REPORTED MAIN ROTOR TRANS. CHIP LIGHT CAME ON. CHIP PLUGS INSPECTED AND FOUND METAL PARTICLES ON UPPER CHIP DETECTOR. HELICOPTER FLOWN AGAIN AND AFTER A FEW HOURS, THE LIGHT CAME ON AGAIN. CHIP PLUGS INSPECTED AND FOUND METAL ON UPPER PLUG. MAST ASSY REPLACED. CAUSE WAS FAULTY BEARING.