What was found
AFT BELLY SKIN STRINGER R51 BS 1800 CORROSION BULGE VISIBLE FROM EXTERIOR. CUTOUT BADLY CORRODED SKIN AREA. REMOVED CORROSION FROM STRINGER. DOUBLER WITHIN LIMITS IAW 53-30-03. RII INSP: ACCOMPLISHED ECI PER B747 NDT MANUAL D-6-7170, PART 6, 51-00-00 FIG 23, NO DEFECT DETECTED: LAY OUT PATTERN FOR FASTENERS, PICKED UP HOLES, FABRICATED DOUBLER AND FILLER AND INSTALLED REPAIR PER SRM 53-30-03, FIG 37A. RESTORED ORIG FINISH PER 747MM 20-24-11.