What was found
CORROSION ON INTERCOSTALS (3 EAS) IN STA. FS= 349 TO FS= 364 NEAR STGR 27 AT MAIN AVIONICS COMPARTMENT. CORROSION ON INTERCOSTAL STGR 26 RH AND FS 364.00 TO FS 349.00 WAS REMOVED PER CRJ 900 SRM 51-21-06-001-001-A01 EVALUATE WITHIN OF LIMITS PER CRJ900 SRM 53-21-23-101-003-A02, DUE TO EXCESSIVE CORROSION INTERCOSTAL (2EAS) RT AND LT SIDE STGR 27, BTW FS 364.00 TO FS 349.00 WILL BE REPLACED IAW SRM 53-21-23-101-003-A02 AND INSTALLED IAW SRM 51-42-21-001-001-A01 AND SRM 51-42-06-001-001-A01.