What was found
DURING 100 HR INSPECTION, THE MAIN ROTOR DRIVESHAFT WAS REMOVED FOR INSPECTION. THE MECHANIC LOOKED DOWN THE MAST AND FOUND THE PAINT ON THE INSIDE DIAMETER WAS BLISTERED AND PEELING. THE MECHANIC ALSO NOTICED PAINT ON THE TOP OF THE MAIN TRANSMISSION SPLINES. THE MAIN ROTOR MAST WAS REMOVED AND IT WAS NOTICED THAT THE PAINT ON THE BOTTOM FLANGE WAS ALSO PEELING AND THE INSIDE WAS CORRODING. THE MAIN TRANSMISSION WAS REMOVED FOR CONTAMINATION AND INSPECTED. THE MAIN ROTOR MAST WAS REPLACED. THE MANUFACTURE WAS NOTIFIED. THE MAST WAS INSTALLED 11-13-2000.