What was found
ON RETURN LEG, APPROX 8 MILES FROM BASE MED CREW NOTICED FUMES IN AFT CABIN AREA. FLT CONTINUED, ODOR DISSIPATED AND ACFT LANDED AT BASE IN APPROX 4 MINUTES. NO CHANGES IN GENERATOR LOADS OR OTHER INDICATIONS OF A PROBLEM WITH THE ACFT. UPON LANDING AT BASE, NOTED THE GREEN ECS ADVISORY LIGHT WAS NOT ILLUMINATED ON CAD. DURING MX TROUBLESHOOTING OF AIR CON SYSTEM, FOUND AIR CON CIRCUIT BREAKER TRIPPED. TRIPPED CIRCUIT BREAKER CAUSED "ECS" CAUTION LIGHT ON CAD TO EXTINGUISH. DURING NORMAL OPS WITH AIR CON ON, "ECS" LIGHT IS ILLUMINATED. INSPECTION REVEALED COMPRESSOR CLUTCH INOP. NO VISUAL INDICATION OF OVERHEATING, SUSPECT CLUTCH WAS CAUSE OF ODOR. R & R AIR CON COMPRESSOR CLUTCH ASSY WITH NEW.