As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
***WHILE A/C WAS OUT OF SERVICE FOR A HEAVY CHECK*** CENTER FUSELAGE III PASSENGER CABIN FLOOR STRUCTURE, CORROSION FOUND AT GUSSET PLATE FRAME 90 RBL 24" AREA. REMOVED AND REPLACED GUSSET IAW SRM 51-41-02. A/C REMAINS OUT OF SERVICE FOR HEAVY CHECK COMPLETION.