As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) MAIN GEARBOX CHIP DETECTOR WARNING TRIGGERED IN FLIGHT. THE ACFT RETURNED TO BASE. THE MAIN CHIP DETECTOR WAS REMOVED FROM THE MGB FOR INSP. A PIECE OF FERROUS MATERIAL WAS FOUND ATTACHED . CYLINDRICAL IN SHAPE. APPOX .800IN LONG X .200 IN DIAMETER. ACFT REMOVED FROM SERVICE AND MGB MODULE REPLACED.