As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFT CARGO DOOR LOWER MAIN SILL HAS COROSION. GROUNDED - YES. REMOVED CORROSION DETERMIND TO BE OUT OF LIMITS IAW BOEING 737-900 SRM 53-60-15-1A-1, REMOVED AND REPLACED AFT CARGO DOOR LOWER MAIN SILL WEB IAW BOEING 737-900 SRM 51-40-02-0G-0 W-1.5" O-.050 R-.025 L-1" D-.025".