As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RT WING REAR SPAR UPPER CAP WS178 AT NACELLE AFT ATTACH PLATE. DISSIMILAR METAL CORROSION ATTACKING UPPER CROWN AND AND VETICAL LEG OF THE SPAR CAP. CORROSION WAS VISUALLY DETECTED AT SCHEDULED DEPOT LEVEL INSPECTION. CORROSION EXCEEDED MAXIMUM NEGLIGIBLE LIMITS.