As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PASSENGER DOOR: INTERCOSTAL DD4 HAS CORROSION (MARKED). (C-CHECK) RO 4/16/2020 CORROSION IS PRESENT ON ALL 3EA ELEMENTS AND COVERS MORE THAN 30% OF PART OUT OF LIMITS REF CRJ200 SRM. REPLACE INTERCOSTAL DD4. REMOVED PAX DOOR MID DD4 INTERCOSTAL IAW CRJ 200 SRM. INSTALLED NEW PAX DOOR INTERCOSTAL DD4 IAW CRJ 200 SRM. PRESSURE CHECKS GOOD.