As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MAIN CABIN FLOOR SUPPORT STRUCTURE INTERCOSTAL BETWEEN FRAMES AT STA 277 AND 294.5 AT BL0 HAS 2EA CRACKS AT THE FLOORBOARD ATTACH FASTENER HOLES. REMOVED AND REPLACED FLOOR SUPPORT BETWEEN STA 277 AND STA 294.5 IAW DWG 141A5400 REV-, & SRM 51-40-05.