What was found
DURING IMBV INSPECTION, QA FOUND THE CENTER BEAM BETWEEN FRAME 50 - 51 HAD CORROSION AFT OF WING BOX. AIRCRAFT WAS REMOVED FROM SERVICE FOR IMBV INSPECTION. PERFORMED PERMANENT REPAIR ON CENTER BEAM BETWEEN FRAME 50 - 51 JUST AFT OF WING BOX IAW ERS-EM-53MR-1522. AIRCRAFT WILL BE RETURNED TO SERVICE AFTER IMBV INSPECTION, REPAIR MATERIALS, GUSSET A7475-T761 0.040, LEFT SPLICE AL 7475 - T761, 0.040.