As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT HAS A HISTORY OF DIRTY SOCK ODOR. FOUND OIL ON DRAIN LINE FITTING & DRAIN CAVITY ON APU LOAD COMPRESSOR. REPLACED APU PER T/C 78349010. ACCOMPLISHED APU PNEUMATIC DUCT SYSTEM BURN OUT IN REF TO AMM 21-00- 01-100-801, NO ODOR NOTED AT THIS TIME.