What was found
AT 29,000 FT IN CRUISE FLT BURNING RUBBER SMELL NOTED IN COCKPIT AND CABIN. SMELL DISSIPATED WITHIN ONE MINUTE. GROUND RAN AC AND PACK SYSTEMS AND INSPECTED PACK, APU, AND RECIRC SYSTMES IAW FIM TASK 21-20-00-810A. NO SMOKE SMELL NOTED OK FOR SERVICE.