As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER REMOVAL MAIN CABIN FLOOR PANEL WEB, FOUND INTERCOSTAL CORRODED AND BROKEN THRU AT STA 169 LBL 55. REMOVED INTERCOSTAL AT MAIN CABIN STA 169 LBL 55 IAW MD90 SRM 51-30-02 PG1 VOL 2. FABBED INTERCOSTAL. INSTALLED INTERCOSTAL IAW MD90 SRM 51-10-05 PG 1 AND MD90 SRM 51-30-02 PG 1. AT SAA/SAT DURING HMV.