What was found
BEFORE REMOVING HI-LOKS ON LT & RT ENGINES AFT MOUNT, AFT SIDE OF THRUST SHAFT HOLE STARTED TO SPIN. CONFIRMED LT & RT ENGINE AFT MOUNT THRUST AFT FASTENERS HOLES ARE WITHIN LIMITS. DURING INVESTIGATION NOTED HOLE 4 RT LWR HOLE TO HAVE DAMAGE IN COUNTER BORE WALL AND SURFACE DAMAGE TO FASTENER SHOULDER LANDING. BLENDED DAMAGE IAW REO 670-54-51-093 REV, SRM 51-42-21-001-001-A01, AND DWG MM670-37001 REV AH ALL CHECKS GOOD AT TIME OF REPAIR COMPLIED WITH TASK CARD 51-900-1002-SKY RE-INSPECTIONS REQUIRED TO ALL 4 HILITE PINS AT INTERVALS TO NOT EXCEED 2000 FLIGHT HOURS TO ENSURE FASTENERS ARE NOT MOVING