As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FOUND CORROSION ON FORWARD SIDE OF MAIN WING SPAR LOWER CAP BOND ASSY. THE AFFECTED AREA IS UNDER THE CABIN FLOOR IN THE CABIN. CORROSION WAS FOUND ON THE FORWARD FACE OF THE SPAR CAP AND WAS DISTRIBUTED IN SMALL AREAS ACROSS THE SPAR, JUST ABOVE THE EDGE OF THE SEALANT THAT IS USED TO SEAL THE SPAR RIVET FLANGE. DAMAGE WAS DETERMINED TO BE NEGLIGIBLE AFTER CORROSION REMOVAL.