What was found
WALL/FLOOR ON LEFT SIDE OF ACFT BY ROW 24 WAS EXTREMELY HOT WITH A BURNING SMELL. DUCT ASSEMBLY SIDEWALL RISER P/N 214U2119-11 FOR ZONE C WAS FOUND WITH HEAT DAMAGE AT THE HOT TRIM AIR INLET INTERFACE (STA 1153.66). THE DUCT ASSY EXHIBITED A DARK BROWN COLOR WITH SIGNIFICANT STRUCTURAL DAMAGE TO THE LOWER SECTION, ADJACENT TO THE CONNECTION TO THE UNDERFLOOR TRIM AIR DUCT ASSY P/N 213U2107-7. THE DAMAGE WHICH INCLUDES A LARGE HOLE, APPEARS TO BE INITIATED AT THE TRANSITION POINT WHERE THE FLOW CHANGES DIRECTION (SMOOTH CURVATURE). IN ADDITION, DURING REMOVAL OF JOINT ASSY P/N CF15-250, SLEEVE P/N 24098-250 WAS FOUND BROKEN IN PIECES.