As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FAINT MUSTY SMELL DETECTED ON DECENT FROM 5000'. THRUST AT IDLE. PACK 1 SELECTED OFF SMELL WENT AWAY.-PERFORMED ISOLITALION OF ORDOR IAW AMM 21-00-00. RUN ENINES AND APU TO FIND MUSTY SMELLY. CUOLDNOT DUPLICATE. NO SMELL NOTICED AT THIS TIME A/C OK FOR CONTINUED SERVICE.