What was found
AIRCRAFT WAS GROUNDED: DURING ROTATION THROUGH APPROXIMATELY 1,500 SMELLED "DIRTY SOCKS" SMELL. DURING DECENT FROM 5,000 TO 4,000 BOTH CAPTAIN AND FIRST OFFICER SMELLED FUMES AGAIN. WHILE CROSSING RUNWAY 12 AT MIA AT ABOUT 35% N2 SMELLED FUMES AGAIN. ACCOMPLISHED WORKCARD 08L00021001 AND TSI #0113351, NO SMELL AT THIS TIME NOTED, NO FAULT FOUND.