What was found
SAW AND SMELLED SMOKE COMING FROM THE AFT CABIN. THIS HAPPENED DURING FLIGHT AT APPROX 1600 FEET ABOVE THE GROUND, MANUVERING TO LAND. T/S SYSTEM, OPS CHECKED OVERHEAD BLOWER, NO SMOKE. NO EVIDENCE OF BINDING. RAN ACFT, TESTED ENVIROMENTAL SYSTEM, NO SMOKE SMELL IN CABIN/COCKPIT, NO SMELL WITH OVERHEAD. REMOVED COALESCER SOCK, NO EVIDENCE OF OIL. REINSTALLED SOCK, THERE IS A SMOKEY SMELL IN TAIL ACCESS AREA. ACCESSED AFT BLOWER MOTOR AT AFT TOLET AREA. REMOVED & INSTALLED NEW ONE. OPS CHECK GOOD. CLOSED ACCESS IAW 560 MM CH 21-21-06.