As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT#469, BOS-FLL. 'STRONG LEVEL 2 DIRTY SOCK. DESCENDING FROM 4K TO 3K ON APPROACH. PILOTS THOUGHT IT SOMEWHAT DISSIPATED. FLIGHT ATTENDANT'S DID NOT; FOUND SOURCE OF SMELL: APU HAS OIL SATURATION. "COMPLIED WITH INFORMATION NOTICE 2017-T015, SECTION B2. DECONTAMINATION LEVEL "B" WAS ACCOMPLISHED PER TSM: 05-50-00810-831-A. A/C IS OK FOR SERVICE.'