What was found
(CAN) DURING LAST SHUT DOWN OF THE DAY THE PILOT NOTED THAT ON WHINED DOWN THERE WAS A SQUEAL COMING FROM THE BACK OF THE AIRCRAFT. IT WAS DETERMINED THAT THE TAIL ROTOR PITCH CONTROLLER BEARINGS WERE MAKING THE NOISE. AFTER A BRIEF INQUIRY WITH ROBINSON TECHNICAL SUPPORT IT WAS DEEMED UNSERVICEABLE. THE CAUSE IS STILL UNKNOWN BUT THE PART HAS BEEN REPLACED AND WILL BE SENT BACK TO RHC FOR INSPECTION. WE SUSPECT DUE TO HEAVY RAIN OR POSSIBLY CLEANING PRACTICES THAT THE BEARINGS GREASE MAY HAVE BEEN WASHED OUT CAUSING THE SQUEALING NOISE. (TC# 20190626014)