What was found
AIRCRAFT WAS GROUNDED: FLIGHT ATTENDANT REPORTED STRONG DIRTY SOCK SMELL IN THE MID CABIN ON APPROACH THRU LANDING. MAINTENANCE FOUND THE APU WAS OVERSERVICED AND DRAINED THE EXCESS OIL PER AMM 49-91-42. (AALA202505164104) MAINTENANCE ALSO FOUND THE APU GEARBOX VENT LINE HAD EVIDENCE OF COKING AND WAS CLOGGED. MAINTENANCE REPLACED THE VENT LINE PER AMM 49-26-55. (AALA202505165926) MAINTENANCE ACCOMPLISHED THE DECONTAMINATION OF THE ENVIRONMENTAL CONTROL SYSTEM PER TASK CARD 26L00021014. A SATISFACTORY LEAK / OPERATIONAL CHECK WAS ACCOMPLISHED WITH NO LEAKS OR ODORS NOTED.