What was found
WHILE AIRCRAFT WAS RETURNING TO BASE, SMOKE AND A BURNING SMELL WAS COMING FROM THE UPPER CIRCUIT BREAKER PANEL CLOSE TO THE GOVERNOR CONTROL BREAKER. AFTER FURTHER TROUBLESHOOTING, IT WAS DETERMINED THAT A WIRE FOR THE GOV CONTROL BREAKER HAD CHAFED NEXT TO A STANDOFF AND METAL SUPPORT. THE GROUNDED WIRE CAUSED THE BREAKER AND WIRE TO SMOKE AND NOT TRIP. SINCE THE BREAKER HAS SIGNS OF OVERHEATING, BURNING SMELL, THE WIRE AND BREAKER WERE BOTH REPLACED AS REQUIRED.