What was found
AIRCRAFT WAS GROUNDED: DURING IDLE DESCENT WITH APU OFF, GOT DIRTY SOCK ODOR OUT OF PACK ON FLIGHT DECK. NO ODOR REPORTED IN CABIN. MAINTENANCE FOUND OIL IN THE APU INLET AND CLEANED THE APU PER TASK CARDS 26L00021001, 21L00021002, 26L00021004, 26T31049006 AND 26L31049009. A SATISFACTORY LEAK CHECK WAS ACCOMPLISHED WITH NO ODORS NOTED.