As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SEVERE CORROSION ON THE REAR WING CARRY-THROUGH SPAR LOCATED AT STA 128.737. THE CORROSION IS LOCATED WHERE THE WING REAR ATTACH FITTING IS LOCATED. PIPER SB 977 COVERS THIS SUBJECT. THIS CORROSION WAS VERY DIFFICULT TO DETECT EVEN WHEN COMPLYING WITH THE PIPER SB.