What was found
AFTER LANDING, THE PILOT IDENTIFIED AN ABNORMAL SOUND FROM THE REAR PORTION OF THE ENGINE. THE PILOT RECORDED A VIDEO TO CAPTURE THE SOUND. AFTER THE ROTOR STOPPED SPINNING, THE PILOT CALLED MAINTENANCE TO INVESTIGATE. THE REDUCTION GEAR CHIP PLUG WAS CHECKED, AND REVEALED MULTIPLE CHIPS. THE FULL FLOW ELECTRICAL CHIP DETECTOR ALSO REVEALED MAGNETIC CHIPS. THERE WERE NO ENGINE PARAMETER DEGRADATION INDICATIONS IN ANY PHASE OF FLIGHT. THERE WAS ALSO NO COCKPIT CHIP INDICATION. WHILE FOLLOWING THE ENGINE MANUAL CHIP IDENTIFICATION TASK, IT WAS DETERMINED THAT THIS WAS A CLASS B PARTICLE EVENT. THE PARTICLES WERE SENT FOR ANALYSIS. THE CHIPS WERE IDENTIFIED AS HIGH SPEED CHIPS, MOST LIKELY ORIGINATING FROM THE MODULE 4 AND/OR MODULE 5. THESE MODULES HAVE BEEN REMOVED AND THEY ARE BEING SENT FOR TEARDOWN AND CORRECTIVE ACTION.