As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
UPON REMOVAL OF THE LEFT SIDE UNDER-WING (RIVETED ON) AFT EXHAUST FAIRING WHILE PERFORMING SID 20000 CYCLES/8100 LANDINGS INSPECTION, AN AREA OF MODERATE TO SEVERE EXFOLIATION CORROSION WAS DISCOVERED ON THE WING SKIN UNDERNEATH THE EXHAUST FAIRING. THIS CORROSION WAS NOT VISIBLE WITH THE RIVETED FAIRING INSTALLED.