As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON TAKEOFF AFTER RETRACTING L/GEAR, LOUD BANG FOLLOWED BY SMOKE IN CABIN. A/C RETURNED TO GATE. FOUND DUCT FROM RT PACK HOT AIR SIDE OF MIX VALVE DISCONNECTED AND COLLAPSED (P/N 65-54474-1). MUFFLER 21-20-0-46A REF G COLLAPSED(P/N 65-78947-10) AND MIX CHAMBER REF 360 (P/N 65-54472-8) PARTIALLY COLLAPSED. DUCTS REPLACED AND SYS CHKS OK.