As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FRAME AT FS 333 IS CORRODED ON AFT SIDE AT STR 21L. C-CHECK RO 10/13/2020. REMOVED CORROSION AT FS 333 FRAME AT STGR 21L, FOUND TO BE OUT OF LIMITS. REMOVED AND INSTALLED NEW FRAME SECTION AT FS 333.00 FROM STGR 18L TO STGR 23L, REF CRJ200 SRM AND DWG. OPS TEST AND PRESSURE CHECK GOOD. COMPLIED WITH TASK CARD.