As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFT CARGO DOOR SURROUND LOWER SILL WEB MULTIPLE AREAS OF CORROSION BETWEEN STA 807 TO STA 847. GROUNDED - YES. BLENDED CORROSION, FOUND TO BE OUT OF LIMITS IAW B737-900 SRM 53-60-15-1A-1. REMOVED AND REPLACED SILL WEB IAW B737-900 SRM 51-40-02-0G-0W= 1.25O= .050 R= .042 L= 3.00 D= .008.