What was found
DURING INSPECTION AFTER ENGINE OIL COOLER DRIVE SHAFT FLEX PACK FAILURE. THE AIRFRAME WAS FOUND TO BE CRACKED APPROXIMATELY 90 PERCENT AROUND THE CIRCUMFERENCE OF THE TUBE. THIS WAS BELOW THE WELD, RT SIDE, AFT OF RT AFT TRANSMISSION MOUNT AREA. RECOMMEND A ONE TIME INSPECTION (VISUAL) OF THIS AREA. AFTER LANDING FOR HIGH OIL TEMP. THE OIL COOLER DRIVESHAFT WAS FOUND LAYING ON THE ENGINE. EXAMINATION FOUND THAT BOTH FLEX PLATES HAD SEPARATED. ONE BOLT WAS FOUND TO HAVE 2 BEVELED WASHERS ON ONE SIDE OF FLEX PLATE INSTEAD OF 1. ONE WAS FOUND TO HAVE FLAT SIDE OF WASHER NEXT TO FLEX PLATE. RECOMMEND ONE TIME INSPECTION, FOR PROPER INSTALLATION.