What was found
CRACKS HAVE BEEN FOUND IN THE FIELD DURING ROUTINE VISUAL INSPECTIONS OF ENGINE MOUNT TRUSS/COWLING MOUNT ATTACH BRACKETS. THE CRACKS FOUND ARE ALMOST ALWAYS EXCLUSIVE TO THE UPPER RIGHT ENGINE MOUNT TRUSS (NR 1 ENGINE TRUSS UPPER INBOARD, NR 2 ENGINE TRUSS UPPER OUTBOARD). WE BELIEVE THE CRACKS ARE OCCURRING DUE TO EXCESSIVE VIBRATION CONDITIONS OR INADEQUATE WELD QUALITY DURING MANUFACTURING PROCESS. THE AFFECTED ENGINE TRUSS PART NUMBERS ARE: P/N’S 101-910122-53, 101-910122-69, ASSEMBLIES 130-910000-617, AND 130-910000-618. REPAIR OPTIONS CONSIST OF COMPLYING WITH BEECHCRAFT STANDARD REPAIR TITLED-CRACK, ENGINE MOUNT TRUSS, COWLING MOUNTING BRACKETS, DRAWING NO. SR-KA-00034, REV. 1, OR REPLACING CRACKED ENGINE TRUSS WITH APPLICABLE PART NUMBER REFERENCED IN CURRENT BEECHCRAFT KING AIR 300 SERIES ILLUSTRATED PARTS CATALOG.