As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CORROSION ON INTERCOSTAL ATTACHED TO STRINGER 20RH BTW STA. FS=310 TO FS=349 AT MAIN AVIONICS COMPARTMENT. CORROSION ON INTERCOSTAL ATTACHED TO STRINGER 20RH BTW STA. FS=310 TO FS=349 AT MAIN AVIONICS COMPARTMENT WAS REMOVED PER CRJ900 SRM 51-21-06-001-001-A01 AND BTW FS319 TO FS349 WAS EVALUATED. WITHIN LIMITS AND BTW FS310 TO FS319 WAS EVALUATED OUT OF LIMITS PER CRJ-900 SRM 53-21-23-101-002-A02 AND INTERCOSTAL OUT OF LIMITS WAS REPLACED PER CRJ900 SRM 51-42-21-001-001-A01