As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CORROSION ON INTERNAL PRODUCTION DOUBLER OF AFT MAST DRAIN STA. FS=1031-1051 BETWEEN STGR 27 TO 26RH AT AFT CARGO COMPARTMENT. PRODUCTION DOUBLER OF AFT MAST DRAIN STA. FS=1031 -1051 BETWEEN STGR 27 TO 26RH AT AFT CARGO COMPARTMENT WAS REPLACED PER CRJ-900 SRM 51-42-06-001-001-A01.