What was found
DURING TO ROLL AND INITIAL CLIMB UPTO 200FTA STRONG BURNING RUBBER SMELL FELT THROUGHOUT THE AIRPLANE / [01] ACCP?D CONDITIONAL INSPECTION IAW AMM 05-51-56. ALSO CHECKED AACU; NO FAULTS PRESENT. INSPECTED BOTH PACK BAYS WITH PACKS RUNNING; ALSO RAN BOTH ENGINES TO 83% N1 WITH PACKS IN AUTO AND HIGH. COULD NOT DUPLICATE ANY SMELLS OR FIND ANY DEFECTS. REMOVED AND REPLACED BOTH RECIRC FAN HEPA FILTERS AS PRECAUTIONARY PER AMM 21-25-01. A/C OK FOR SERVICE.