As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING C-CHECK, CABIN INTERCOSTAL AT RBL 24 IS CORRODED AT STA 1148. REMOVED INTERCOSTAL AT STA 1148 AND RBL 24 IAW B-727 SRM 51-30-2. FABRICATED NEW INTERCOSTAL IAW B-727 SRM 53-10-5. INSTALLED NEW INTERCOSTAL AT STA 1148 RT FROM RBL 20 TO RBL 65 IAW B-727 SRM 51-30-2.