What was found
AD NO. 2001-CE-45-4D WING CENTER SECTION INSPECTION FOR CORROSION. SERVICE BULLETIN NO.31 USED METHOD 1, INSPECTION HOLES IN WING WALK. INSPECTED FRONT AND REAR SPARS. NO EVIDENCE OF CORROSION. FOUND CORRODED WING WALK TRAILING EDGE RIB, RIGHT SIDE. REMOVED AND REPLACED THIS RIB WITH NEW MANUFACTURED PART. CLEANED LIGHT CORROSION FROM TRAILING EDGE WINGWALK OUTER SKINS, TREATED AREA WITH ZINC CHROMATE. TREATED WING CENTER SECTION WITH CORROSION INHIBITOR.