What was found
WHILE IN CRUISE FLIGHT, DEBRIS BLEW INTO MY FACE FROM THE PILOT SIDE, AC VENT. SIMULTANEOUSLY A VIBRATION OR RATTLING EMANATING FROM THE FRONT INSTRUMENT SHROUD STARTED AND BEGAN INCREASING IN INTENSITY, AND I DETECTED THE SMELL OF BURNING RUBBER. I TURNED OFF THE AC AND RETURNED TO BASE. THIS AIRCRAFT HAS BEEN RETURNED TO REVENUE SERVICE, REF # MEC-014713. REPAIRED RH EVAPORATOR BLOWER MOTOR FAN, REPLACED LH FORWARD BLOWER MOTOR.