As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CORROSION ON STGR 21RH BTW FS421.00 TO FS437.00. DUE TO EXCESSIVE CORROSION STRINGER 21RH BTW FS=394 TO FS=475 WAS EVALUATED OUT OF LIMITS PER CRJ900 SRM 53-00-00-101-001-A01 AND WAS REPLACE PER CRJ-900 SRM 51-42-06-001-001-A01 AND SRM 51-42-21-001-001-A01