As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DIRTY SOCK ODOR EVENT DESCENDING FROM 4000-3000 ISOLATE PACK # 1 ODOR DISSIPATED. DESCRIPTION OF ODOR/FUMES: TEMPORARY, DIRTY SOCKS SMELL. APPARENT CABIN SOURCE: UNKNOWN. FLIGHT DECK. NO VISIBLE SMOKE/HAZE. NO MEDICAL ATTENTION REQUIRED.-PERFORMED IDENTIFICATION OF THE CAUSE OF ODOR IAW AMM 05-50-00 PEROFRMED IDLE RUN OF ENG 1 & ENG 2 IAW AMM 71-00-00. NO LEAKS NOTED CANNOT DUPLICATE ODOR EVENT.