As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU COMPARTMENT LH LOWER INSULATION MOUNTING STRIP HAS NUMEROUS CORROSION SPOTS AND CHAFE MARKS BETWEEN STA 1088 THRU STA 1156. GROUNDED - YES. FOUND TO HAVE 100% MAT LOSS REMOVED AND REPLACED L/H SIDE LOWER CHORD (INSULATION MOUTNING STRIP) IAW B737-900 SRM 51-40-02-0G-0W: 1 O: .063 R: 0 L: 12 D: .063.