What was found
(CAN) DURING APPROACH, AN ENGINEER ONBOARD SMELLED ODOR OF BURNING ELECTRICAL WIRES. THE AIRCRAFT LANDED WITHOUT FURTHER INCIDENT. FURTHER INVESTIGATION FOUND IGNITION SWITCH WAS THE CULPRIT. THE CONTACTS OVERHEATED CAUSING THE PLASTIC TO SLIGHTLY BURN. ONE MAG CONTACT WAS FOUND GROUNDED DURING FUNCTION TEST OF SWITCH. THE SWITCH WAS REPLACED AND NO FURTHER DEFECTS WERE NOTICED, FLIGHT CONTINUED. THE COMPANY HAS NOTIFIED MFG AND INCORPORATED AN INSPECTION ON THE IGNITION SWITCHES. IGNITION SWITCH P/N A166-1, ALT P/N 10-357200-1.