What was found
FT # 6150, . A STRONG OILY SMELL ON DECENT BELOW 10000 FEET IN CABIN AND IN COCKPIT. ( PACKS - BOTH ); AS PER INFO NOTICE 2017-T015D PERFORMED DECONTAMINATION OF THE ENVIRONMENTAL CONTROL SYSTEM (ECS) IAW AMM 21-00-00 OF APU AND BOTH ENGINES. AS PRECAUTIONARY ACTION REMOVED AND REPLACED PACK#1 AND PACK#2 OZONE FILTER IAW AMM 21-51-41. ALSO AS PRECAUTIONARY ACTION REMOVED AND REPLACED BOTH RECIRCULATION FILTERS IAW AMM 21-21-41. A/C OK FOR CONTINUED SERVICE AT THIS TIME. MDDR CLEARED, MX-4 UPDATED.