As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
F/A REPORTED BURNING SMELL BACK OF A/C AFTER BITING DUCT OVERHEAT SYSTEM, FAULT CODE 54, AFT BULKHEAD SECTION 48, FOUND DUCK CRACKED 5 INCHES AT ABOVE AFT BODY ACCESS PANEL.DUCT IS MARKED.INOPING APU. NEED DUCT. APPLIED MEL TOMC UPDATE: SEE LP 8582814 FOR CORRECTIVE ACTION. APU BLEED ON MEL FOR DAMAGED DUCT. IPC 36-11-10-01 ITEM 72. MFG 212N3046-7.