What was found
BAD SMELL COMING FROM CONDITIONED AIR DEBRIEDED CREW ON ARRIVAL, CREW REPORTED ODOR OF SMELLY DIRTY SOCKS, IN THE FLIGHT DECK AND CABIN DURING TAKEOFF AND CLIMBOUT, THEN WENT AWAY DURING CRUISE BUT RETURNED ON DESCENT. ACCOMPLISHED HIGH POWER RUN, CYCLED A/C PACKS, NO ODOR DETECTED. REPLACED BOTH LEFT AND RIGHT RECIRCULATION AIR FILTER IAW TASK 21-25-01/401.