What was found
PILOT NOTICED A STRANGE NOISE DURING SHUT DOWN. UPON INSPECTION OF THE AIRCRAFT, HE FOUND THAT M/R BLADE S/N 009999-H994 HAD A CRACK ON BOTH THE TOP AND BOTTOM SKINS 15.75 INCH FROM THE DAMPER BRG CASTING. THE AIRCRAFT HAD BEEN IN 18 HRS BEFORE WITH A VERTICAL PROBLEM, BUT WE WERE ABLE TO CHANGE A COUPLE OF BELLCRANKS AND TRACK THE MAIN ROTOR AND MAKE THE AIRCRAFT SMOOTH AGAIN. AIRCRAFT HAS BEEN DOING XMAS TREES FOR JUST UNDER 300 HRS.