As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IN FLIGHT, PILOT AND PASSENGERS DETECTED THE ODOR OF SMOKE. NO SMOKE OR EVIDENCE OF FIRE WAS VISIBLE INSIDE OR OUTSIDE THE ACFT. PILOT SHUTOFF BOTH GENERATORS AND AIR CONDITIONER IAW CHECKLIST. ACFT MADE A PRECAUTIONARY LANDING AND PERFORMED AN EMERGENCY SHUTDOWN OF BOTH ENGINES. NO EVIDENCE OF SMOKE, FIRE, OR BURNING WAS FOUND DURING POST-FLIGHT INSPECTION. MX PERSONNEL LOCATED A BROKEN AIR CONDITIONER DRIVE BELT. ACFT WAS RUN AND FLOWN WITH NO FURTHER SMOKE ODOR.