As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE AIRCRAFT WAS IN HEAVY CHECK MAINTENANCE FOUND THE RIGHT FLOOR GUSSET AT FRAME 90 CORRODED. MAINTENANCE REMOVED AND REPLACED THE RIGHT FLOOR GUSSET AT FRAME 90 IAW EMB 170 SRM 51-41-02. THE AIRCRAFT IS OUT OF SERVICE IN HEAVY CHECK.