As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
INTERCOSTAL DD1 IS CORRODED IN SEVERAL LOCATIONS (NOTED AFTER INTERNAL SKIN WAS REMOVED). C-CHECK RO 12/05/2020. PAX DOOR MID DD1 INTERCOSTAL ORIGINAL MATERIAL THICKNESS IS 0.050", IAW CRJ 200 SRM. EXFOLIATED CORROSION AT MULTIPLE LOCATION AND MORE TWO ELEMENT AT GIVEN CROSS-SECTION OUT OF LIMITS, IAW CRJ 200 SRM. INSTALLED NEW PAX DOOR MID DD1 INTERCOSTAL, IAW CRJ 200 SRM AND BOMBARDIER DWG. LEAK CHECKS GOOD.