As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFT SERVICE AREA, APU INTAKE PLENUM FLANGE ON BULKHEAD BS 1088 HAS CORROSION ON THE FWD FACE. ACFT GROUNDED. REMOVED AND REPLACED AFT SERVICE AREA, APU INTAKE PLENUM FLANGE IAW B737 900 SRM 51 40 02 0G 0 FIR 8 AND PARA 4 W 1.50 O .071 R .061 L 6 D .010.