What was found
AT CRUSE, NOTICED A SLIGHT ODOR OF BURNED RUBBER. SMELL IS CONFINED TO THE COCKPIT ONLY. UNABLE TO DETERMINE ORGIN. CLEARED ABOUT 1 HOUR PRIOR TO TOP OF DESCENT THEN RETURNED IN THE DESCENT, REF PREVIOUS WRITE UP, LOG PG 9806320, 14 AUG 15. OPERATE AIR CONDITIONING PACK ABOUT 1 HOUR AND NO FINDING OF ODOR BURNED RUBBER. PERFORM ACC 1-3 RTS TEST IAW AMM MD 11-21-53-20-700-801, ALL PASSED, AC OK TO SERVICE.