As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING 5C CHECK AND INSPECTION, CORROSION WAS FOUND ON LT WING REAR SPAR LWR SKIN AT WS706 DIMENSION AREA 1.3 INCH X 1.7 INCH. AFTER CORROSION BLENDOUT FOUND MAX BLDOUT DEPT IS BEYOND LIMITATIONS. NO REINFORCEMENT REQUIRED, REMOVE ALL FASTENERS BLEND SMOOTH, INSTALLED ALL LOCK FASTENERS IAW EI-727-090702.