What was found
AFT CARGO DOOR CUTOUT, SUB SCUFF PLATE STRUCTURE HAS AREAS OF CORROSION. GROUNDED - YES. REMOVED CORROSION AT AFT CARGO DOOR CUTOUT WEB, FOUND TO BE OUT OF LIMITS. ORIGINAL MAT. THICKNESS IS .050, MAT. LOSS .008, MAT. REMAINING IS .042 IAW B737-900ER SRM 53-60-15-1A-1. REPLACED AFT CARGO DOOR CUTOUT WEB IAW BAC DWG 146A8120 REV. A AND BAC DWG 146A8340 REV:-, AND IAW SRM 51-40-02 AND SRM 51-40-05.