What happened
Shortly after departing from the airport, the pilot experienced a sudden loss of engine power accompanied by visible flames erupting from the engine cowling. As thick black smoke began to fill the cockpit, the pilot initiated a turn back toward the airport. To maintain visual reference with the ground through the smoke-filled cabin, the pilot opened the side vent window and successfully landed the aircraft in an open field.
After exiting the aircraft, the pilot used a handheld fire extinguisher to combat the flames continuing to belch from the engine compartment. The resulting fire caused substantial damage to the aircraft structure.
The investigation
A physical inspection of the fire area revealed that an exhaust V-clamp was loose and a gasket at the exhaust joints was distorted. This mechanical failure allowed hot exhaust gases to blow by into the engine compartment. These high-temperature gases melted the connection on the fuel boost pump, causing raw fuel to spray into the hot engine area.
Records indicated that the exhaust system had been removed six hours prior to the flight to rework a cylinder and was reinstalled shortly before departure. The investigation determined that the gasket became distorted during this reassembly process, leading directly to the leak and subsequent fire.