What was found
ACFT WAS UNDERGOING ROUTINE INSPECTION AND WIRING REPAIR AT RT ENGINE ALTERNATOR. DURING WIRING INSPECTION WITH POWER `ON`, SMOKE WAS NOTICED COMING FROM THE AFT ENGINE AREA. FURTHER INSPECTION REVEALED, THROUGH THE RT ALTERNATOR FILTER CASE INSPECTION HOLE, ARCING WHEN THE MAIN B FEED WIRE TO THE FILTER WAS MOVED. THE FILTER WAS REPLACED WITH A SERVICEABLE UNIT AND CHECKED SERVICEABLE. THERE WERE NO PREVIOUS REPORTS TO INDICATE A PROBLEM WITH THE ALTERNATOR NOISE FILTER.