Fire in Cockpit Leads to Forced Landing After Muffler Failure (N2648P)

Incident Overview

After 30 minutes of flight, the pilot reported that smoke began entering the cockpit through the right side defrost duct. He elected to divert to the nearest airport, located 14 nautical miles north of his position. Approximately 3 miles from the airport, a fire started inside the cockpit near the right side rudder pedals. The pilot reduced power and began descending toward a field. The last thing he recalled was crossing power lines.

Investigation Findings

A detailed inspection of the muffler revealed two areas of burn-through damage. The aircraft's firewall had an area approximately 14 inches in diameter with indications of severe overheating. Investigators concluded that a faulty exhaust muffler caused the aircraft's firewall to overheat, which in turn led to smoldering of the firewall insulation. Maintenance records did not indicate that the exhaust muffler had ever been replaced.