Forced Landing After In-Flight Fire Caused by Misaligned Exhaust Pipe (N413LL)

Incident Overview and Immediate Events During the flight, the pilot detected smoke shortly after takeoff. The pilot initiated a return to the airport, but the engine subsequently lost total power. The pilot executed a forced landing in a field near the airport, where the aircraft struck a metal fence and a pipe. All occupants successfully evacuated the aircraft. After landing, the pilot observed a fire originating under the engine cowling. Post-accident examination revealed fire damage to the roof, the forward end of the baggage compartment, and the engine accessory area between the firewall and the aft air baffles. Further inspection identified that one of the engine exhaust crossover pipe assemblies was misaligned at the slip joint. An engine manufacturer service bulletin had required inspections of the exhaust system slip and flange joints to detect misaligned components. The last maintenance event occurred approximately 7.5 flight hours before the accident, during which the service bulletin was performed and crossover pipes were replaced. The mechanic who performed the maintenance did not follow the correct procedures for reinstalling the crossover pipe. The inspector who reviewed the work did not examine the installation as it progressed but instead inspected the pipes after they were installed and largely hidden by their protective heat shield. The misaligned exhaust crossover pipe allowed hot exhaust gases to escape into the engine compartment, starting a fire that compromised critical engine fuel and oil lines and caused the loss of engine power.