What was found
FS 621-FS 625 INTERCOSTAL "V CHANNEL" AT STR 13L IS CRACKED ON OTBD FLANGE THAT ATTACHES TO FUSELAGE SKIN IN AFT END OF RADIUS. REMOVED FS 621-625 INTERCOSTAL U-CHANNEL AT STR 13 IAW SRM'S 51-42-06 AND 51-42-21. INSTALLED QTY 3, HI-LITES IN INTERCOSTAL U-CHANNEL AT STR 13 BETWEEN FS 621-625 IAW SRM TASK 51-42-21. INSTALLED QTY 3 HI-LITES AND 3 SOLID RIVETS IN SERVICEABLE INTERCOSTAL U-CHANNEL AT STG 13L BETWEEN FS 621-625 IAW SRM TASKS 51-42-06 AND 51-42-21.