What happened
Following two previous flights where the pilot experienced smoke in the cockpit and performed emergency landings, the pilot attempted a third flight. Shortly after takeoff, the pilot observed smoke filling the cabin and flames appearing near his feet. As visibility decreased due to the accumulating smoke, the pilot returned to the airport for an emergency landing.
The passenger evacuated the Cessna (not specified in source, but implied as the aircraft) before it came to a complete stop, with the pilot exiting shortly after. The aircraft was subsequently consumed by fire.
Prior to this flight, the pilot had attempted to address the smoke issues from the previous two flights with help from local fixed base operator personnel. They identified a loose hose, which the pilot attempted to repair using a clamp purchased from a local store. No maintenance entry was recorded for this repair work.
The investigation
FAA inspectors examined the aircraft and determined that the smoke event was not caused by the loose hose. Instead, investigators found that the engine exhaust muffler had burned through at the bottom left end. This opening allowed exhaust gases and flames to be directed into the engine compartment and toward the firewall.
The intense heat from the exhaust had also ruptured an aluminum hydraulic brake line mounted on the firewall, which contributed to the fire. Maintenance records showed that an annual inspection had been completed on July 6, 2007, only 2.5 operating hours before the accident. At the time of the accident, the aircraft had 3,104.3 hours in service. While the logbook indicated the aircraft was airworthy and compliant with Airworthiness Directive 68-05-01 regarding exhaust inspections, the investigation highlighted that deteriorated exhaust systems can cause engine compartment fires.