What was found
ON SHORT FINAL WITH ENG AND AIRFOIL ANTI ICE ON, A BURNING SMELL WAS NOTICED THRU OUT A/C. SMOKE DETECTOR IN AFT LT LAV WENT OFF. F/A CHECKED LAV AND TRASH BIN, ALL WAS NORMAL. PERFORMED DUCT BURNOUT AND PNEU SYS CK OUT PER M/M, OPS NORMAL. NO SMELL NOTED.