What was found
FLT#1853, JFK-PBI. 'WET MUSTY SMELL REPORTED BY FAS IN REAR CABIN DESCENDING THROUGH CLOUDS BELOW 10K FEET. ON GROUND WITH APU BLEED ON ODOR REACCURED; ACCOMPLISHED INFO NOTICE 2017-T015 TSM 05-50-00-810-831-A FOUND CAUSE TO BE APU BLEED.THE LEVEL OF ODOR IS1 A.A/C HAS BEEN DECONTAMINATED AND NO FUMES NOTED. ODOR OCCURRED WHILE A/C WAS DESCENDING BELOW 10K INTO STORM CLOUD APU PLACED ON MEL ON LOG DEFECT 3709107, ITEM 1 OK FOR SERVICE.