What was found
DURING CRUISE FLIGHT, CABIN FUMES WERE DETECTED, FOLLOWED BY VISIBLE SMOKE. THE FLIGHT CREW EXECUTED THE EMERGENCY PROCEDURES AND CHECKLISTS, WHICH INCLUDED SHUTTING DOWN ALL NON-ESSENTIAL SYSTEMS. TURNING OFF THE FOOT HEATER IMMEDIATELY AFTER DETECTING THE FUMES PREVENTED THEM FROM WORSENING. SHORTLY THEREAFTER, THE SMOKE SUBSIDED AND BEGAN TO DISSIPATE. THE REMAINING DESCENT, APPROACH, LANDING, AND TAXI WERE UNEVENTFUL. A POST-FLIGHT MAINTENANCE INSPECTION DETERMINED THAT THE FOOT HEATER WIRING AT THE CONNECTOR HAD OVERHEATED, MELTING THE PLASTIC CONNECTION COATING. AIRCRAFT CURRENTLY OOS AWT PARTS.