As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LEFT SPONSON AFT PLATE CORRODED. WHEN THE CORROSION WAS REMOVED, THE DEPTH EXCEEDED THE ALLOWABLE LIMIT. THE CORROSION APPEARS TO HAVE STARTED FROM PREVIOUSLY DRILLED HOLES WHICH WERE UNTREATED WITH A CORROSION PREVENTATIVE COMPOUND. THIS SHOULD HAVE BEEN APPLIED DURING MFG.