What was found
FLIGHT ATTENDANT CALLED DURING APPROACH AND REPORTED A DIRTY SOCK AND MUSTY SMELL. NO SMELLED IN COCKPIT. DESCRIPTION OF ODOR/FUMES: TEMPORARY, DIRTY SOCKS/MUSTY DRY SMELL. APPARENT CABIN SOURCE: UNKNOWN. FWD CABIN, MID CABIN, AND AFT CABIN. NO VISIBLE SMOKE/HAZE. NO MEDICAL ATTENTION REQUIRED.-PERFORMED TSM 05-50-00-810-831-A . APU , ENG # 1 & ENG # 2 OIL WITH IN LIMITS NO OIL ADDED. NO ODOR. DISCREPANCY DETECTED. MOC 64493 . A/C GOOD FOR SERVICE.