As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
INITIAL INSPECTION: CORROSION ON INTERCOSTAL ATTACHED TO STRINGER 20RH IN STA. FS=333.00 TO FS= 364.00 AT MAIN AVIONICS COMPARTMENT. SUMMARY:EVALUATED, DUE TO EXCESIVE DAMAGE ON INTERCOSTAL ATTACHED TO STRINGER 20RH IN STA. FS=333.00 TO FS= 364.00 PER CRJ-900 SRM 53-21-23-101-002-A02 AND WAS REPLACED PER CRJ-900 SRM 51-42-20-001-001-A01.