What was found
AFT CARGO DOOR SILL BETWEEN FRAMES 53 AND 56 HAS MULTIPLE AREAS OF CORROSION. BLENDED CORROSION. ACCOMPLISHED HFEC AND ROTOPROBE WITH NO DEFECTS NOTED, AND ACCOMPLISHED UT THICKNESS. FOUND TO BE OUT OF LIMITS. REMOVED AND REPLACED THE DOOR SILL IAW SRM 51-42-1 1-911-001, PARA 2E, SRM 51-72-11-911-001, SRM 53-41-49-283-003.