As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE AC WAS IN FOR HEAVY CHECK FOUND PAX CABIN AFT WET AREA FLOOR STRUCTURE FR 90 RBL 20 GUSSET PLATE FOUND CORRODED. AAR MX REMOVED AND REPLACED GUSSET PLATE PN 170-60257-001 IAW SRM 51-41-02. SEE AAR NRC# -100 FOR WORK PERFORMED. AC REMAINS IN YRQ FOR COMPLETION.