As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SURFACE CORROSION IN 2 SPOTS ON LT FLOOR SILL FS 533L, MARKED. C-CHECK RO 12/04/2020. LT FLOOR SILL FS 533.00 TO FS 581.00 HAS INTERGRANNULAR CORROSION THROUGH ENTIRE THICKNESS OF PART. OUT OF LIMITS. REMOVED CORRODED SILL AND INSTALLED NEW LT FLOOR SILL P/N: SH670-33504-3S FROM FS 533.00 TO FS 581.00, REF CRJ700 SRM DWG. RESTORED FINISH AND APPLIED CIC. COMPLIED WITH TASK CARD. PRESSURE LEAK CHECK GOOD, REF CRJ-700 AMM. SEE CONTINUATION CARD FOR DETAILS.