Incident Overview
Shortly after takeoff, the pilot-in-command noticed a loss of engine power and flames erupting from the engine cowling. The pilot executed a turn back toward the airport as thick black smoke filled the cockpit. To maintain sight of the ground, the pilot opened the side vent window and successfully landed the aircraft in an open field.
Post-Landing Actions
After landing, the pilot exited the aircraft and used a hand-held fire extinguisher to combat the flames emanating from the engine cowling. Despite these efforts, the ensuing fire substantially damaged the aircraft.
Inspection Findings
Inspection of the fire area revealed an exhaust V-clamp that was loose and a distorted gasket at the exhaust joints. This condition allowed blow-by of hot exhaust gases, which melted the fuel boost pump connection, spilling raw fuel into the hot engine compartment and igniting the fire.
Maintenance History
The exhaust system had been removed to rework a cylinder and was re-installed 6 hours prior to the flight. The gasket was distorted during the re-assembly of the exhaust system.