As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: FUME SMELL ON DESCENT. INITIALLY SMELLED ELECTRICAL. THEN TRANSITION TO DIRTY SOCK SMELL. CONFIRMED APU INOP DUE TO OIL INGESTION VIA VISUAL INSPECTION. DEACTIVATED APU BLEED VALVE CLOSED IAW AMM 49-51-00-040-004-A. (OPEN)