What was found
LEFT WING FORWARD SPAR, OUTBOARD UPPER AFT-FACING WING ATTACH FITTING WAS FOUND TO BE CRACKED WITHIN GEAR WELL. THE PART IS SHOWN IN THE 421C IPC, SECTION 03-50, PAGE 16, ITEM 6. THE CRACK MEASURES ROUGHLY 5-1/8" AND RUNS HORIZONTALLY ACROSS SEVEN RIVET HOLES. IT WAS DISCOVERED DURING THE VISUAL INSPECTION DESCRIBED IN THE 421C SERVICE MANUAL SECTION 2-20 "INSPECTION TIME LIMITS", PAGE 17, SECTION W. (WINGS), "WINGS - INSPECT STRUCTURE AND ATTACH POINTS FOR CONDITION AND SECURITY". PARTS REPLACEMENT WAS REQUIRED.