As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AWR HIDDEN DAMAGE IN REF NRC S/N 00252, AFTER INTERNAL PRODUCTION DOUBLER REMOVAL, CORROSION ON INTERNAL FUSELAGE SKIN WAS FOUND ON DOUBLER SETTLEMENT AREA. CORRECTIVE ACTION: AFTER INTERNAL PRODUCTION DOUBLER REMOVAL, ON INTERNAL FUSELAGE SKIN WAS FOUND ON DOUBLER SETTLEMENT AREA WAS REPAIRED. PERFORMED PER CRJ900 AND EA 79-2020-069 REV P2.