What was found
(CAN) IN CLIMB THROUGH 9,700 FEET, THE CREW NOTICED SMOKE IN THE COCKPIT AND RETURNED TO LAND IMMEDIATELY. SMOKE DISSIPATED DURING DESCENT. MAINTENANCE FOUND THE RIGHT ENGINE HAD AN ACCUMULATION OF OIL IN THE COWLINGS COUPLED WITH A LOOSE OIL LINE AND AN OIL SATURATED AMBIENT AIR DUCT. THIS DUCT FEEDS THE BLEED AIR CONTROL PACK WITH AMBIENT AIR MIXED WITH ENGINE BLEED AIR WHICH, IN TURN, IS DISTRIBUTED INTO THE AIRCRAFT. THE SYSTEM WAS MONITORED FOR THE NEXT 25 HOURS WITH NO RECURRENCE.