As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SHIP 5815 ON APPROACH 6000-5000 FEET A MUSTY ODOR BECAME APPARENT IN THE FLIGHT DECK. ODOR PERSISTED UNTIL PARKED AT THE GATE W/ BLEED NOW ON APU. ODOR STILL PERSISTS. R/R RECIRC FILTERS, FOUND OIL CONTAMINATION FROM IN APU BLEED DUCT, REMOVED CONTAMINATION. ALL NO GO PROCEDURES C/W.