What was found
DURING CRUISE FLIGHT, PILOT NOTED A SLIGHT VIBRATION IN THE MAIN ROTOR SYS. THE FLIGHT WAS COMPLETED. UPON POST FLIGHT 1 OF THE 4 UPPER PITCH CHANGE LINK ROD ENDS WERE FOUND TO BE SIGNIFICANTLY WORN. A DETAILED INSP BY MX REVEALED THE PITCH CHANGE LINK ROD END PN 709-0101-18-111 HAD WORN TO THE POINT THE BALL HAD BECAME SEPARATED FROM THE OUTER RACE OF THE ROD END. THE SEPARATION ALLOWED THE ROD END HSG TO CONTACT THE MAIN ROTOR GRIP TRUNNION (TRUNNION PN 709-0101-12-101). PITCH CHANGE LINK ROD END WAS REPLACED, GRIP ASSY. REPLACED, COMPLETED MAIN ROTOR TRACK AND BALANCE - ACFT RETURNED TO SERVICE MARCH 22, 2010.