As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFT DD4 INTERCOSTAL P/N 601R31902-317 CORRODED ON BOTH SIDE OF LIGHTING HOLE (MARKED) (C-CHECK RO 6/22/2021) REPLACED PAX DOOR AFT DD4 INTERCOSTAL. REF CRJ900 SRM 51-42-06-001-001-A01 AND DWG SH670-32280 REV H. COMPLIED WITH TASK CARD 51-900-1002-SKY. NO LEAKS NOTED.