What was found
ON RUN-UP ONCE I GOT UP TO THE FLY POSITION AND WAS STARTING TO PULL PITCH THE MEDIC ASKED ME WHAT ALL THE SMOKE WAS. I LOOKED TOWARD THE REAR LEFT AND WE WERE ENGULFED IN SMOKE. I IMMEDIATELY SHUT THE ENGINE DOWN. I APPLIED THE ROTOR BRAKE AND ONCE THE ROTORS STOPPED, WE EXITED THE AIRCRAFT. I MADE SURE I COULD NOT SEE ANY FIRE AND THE SMOKE STARTED TO SUBSIDED. I OPENED THE ENGINE COWLING TO INSPECT THE AREA. FOUND OIL ALL OVER THE ENGINE DECK AND COWLING. NOTIFIED AIR COM, AM AND MECHANIC. A REAR BEARING CLEANING WAS RECOMMENDED SO WE WILL ACTUALLY BE CHANGING THE MO3 FOR OUR COMPLIANCE. COKING WAS FOUND AT THE REAR BEARING OIL STRUT.