What was found
DURING ROUTINE C-CHECK, CORROSION WAS FOUND AROUND AFT LAVATORY DRAIN, BOX STRUCTURE, AND SKIN. LOCATED AT STR 20, LEFT FS 1183. THE CORROSION WAS REMOVED AND IT WAS DETERMINED TO BE BEYOND LIMITS. REPAIR WAS CARRIED OUT IAW AIA ENGINEERING DEVIATION REPORT NR B2 06413, AIA NON-ROUTINE M40 52862 AND BOEING REPAIR SKETCH CKF-ORD-99-0017RR. (X)