As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MAIN AVIONICS BAY STR 21L BACK-UP SILL FROM FS333.00 AND FS349.00 CORRODED (C-CHECK RO 7/28/2021) REMOVED AND REPLACED BACK UP SILL FROM FS333 - FS349. REF CRJ900 SRM 51-42-06-001-001-A01 AND DWG SH670-31810 REV AE. COMPLIED WITH TASK CARD 51-900-1002-SKY.