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. CORROSION WAS FOUND ON THE FORWARD FACE OF THE SPAR CAP AND WAS DISTRIBUTED ACROSS THE SPAR CAP. RECOMMEND THAT IMPROVED PAINT BE APPLIED TO THE SPAR CAP AND WATER/SEDIMENT DRAINS BE INSTALLED JUST FORWARD OF THE SPAR CAP, NONE ARE INSTALLED AT THIS TIME.