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 LEFT FLOOR SUPPORT BEAM CORRODED AT FRAMES 88 TO 89. MAINTENANCE REMOVED AND REPLACED THE LEFT FLOORBEAM AT FRAMES 88 TO 89 IAW EMB 170 SRM 51-43-01. THE AIRCRAFT IS OUT OF SERVICE IN HEAVY CHECK.