Synopsis
A pilot was observed pouring oil into the right engine haphazardly prior to a flight. After running the engines at mid-range power for about 20 minutes, the airplane taxied out and departed. Following rotation, fire was seen emanating from the right engine. The airplane climbed shallowly and flew low with the right engine on fire, then banked right to return to the airport and descended into a residential area.
Preflight Observations
Witnesses saw the pilot pouring oil into the right engine in a haphazard manner. The pilot then ran the engines at mid-range power for approximately 20 minutes. The airplane subsequently taxied out of the ramp area and departed.
Accident Flight
Fire was observed emanating from the right engine after rotation. The airplane continued in a shallow climb from the runway, flying low, with the right engine on fire. The airplane then banked right to return to the airport and descended into a residential area.
Post-Accident Examination
Examination of the right engine revealed an exhaust leak at the No. 4 cylinder exhaust riser flange. One of the flange boltholes was elongated, most likely from resulting vibration. The fuel nozzle and B-nut were secure in the No. 4 cylinder, but its respective fuel line was separated about 8 inches from the nozzle. No determination could be made as to when the fuel line separated (preimpact or postimpact) due to impact and postcrash fire damage. Examination of the right engine turbocharger showed the compressor wheel had uniform deposits of an aluminum alloy mixture, consistent with ingestion during operation, most likely from melting of the aluminum fresh air duct. Additionally, the right propeller was found near the low pitch position, contrary to the owner's manual emergency procedure to secure the engine and feather the propeller in the event of an engine fire.