What was found
ENROUTE TO KSDF THE CABIN SHOWED SIGNS OF SMOKE WHEN THE RIGHT BLEED AIR WAS TURNED ON. THE SMOKE DISSIPATED WHEN THE RIGHT BLEED WAS TURNED OFF. MAINTENANCE INSPECTED THE RIGHT BLEED AIR SYSTEM AND FOUND RESIDUAL OIL IN THE RIGHT NACELLE BLEED AIR PRE COOLER CAUSING THE SMOKE IN THE CABIN WHEN THE BLEED AIR WAS TURNED ON. REPLACED THE BLEED AIR PRECOOLER. THE CAUSE FOR THE RESIDUAL OIL WAS DUE TO THE RIGHT ENGINE HAVING HIGH OIL CONSUMPTION DUE TO THE ACCY GEAR BOX NOT SCAVENGING THE OIL PROPERLY. THE ENGINE WAS REPLACED ON 11/13/2019.