As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SJO - DURING Q-CHECK, FOUND THE CABIN FLOOR SUPPORT STIFFENER BETWEEN BS 328 - BS 344 LBL 11 WL 208.5 WITH CORROSION. L = 10.0 INCHES. W = 1.509 INCH. D = 0.040 INCH. REPLACED THE CABIN FLOOR SUPPORT STIFFENER BETWEEN BS 328 - BS 344 LBL 11 WL 208.5 IAW BOEING SRM 51-10-1 PAGE 8 AND 51-30-2 PAGE 1. (X)