Event Overview
On May 29, 2020, at about 1130 central daylight time, a Piper PA-24-180 (registration N6989P) was substantially damaged during a forced landing near Humboldt, Tennessee. The pilot and passenger were not injured. The flight was operated under Title 14 Code of Federal Regulations Part 91 as a personal flight.
Preflight and Takeoff
The airplane had been at Humboldt Municipal Airport (M53) for approximately five weeks to have new avionics installed. The installation was completed the day before the flight, and the mechanic had fueled the airplane to a total of 60 gallons. The purpose of the flight was to test and evaluate the new avionics. After a preflight inspection with no anomalies, the pilot and mechanic boarded. During taxi and engine run-up, the pilot noted all engine parameters were normal. He taxied to runway 22 and briefed the mechanic of his intention to remain in the traffic pattern. After applying full engine power, the engine instruments again indicated normal.
Loss of Engine Power
Shortly after lift-off, the engine shuttered and had a sudden reduction in RPM. With the landing gear still down, the pilot pitched the airplane forward, and the engine regained RPM, bringing the nose back up. After clearing over powerlines off the departure end of the runway, the engine backfired, shuttered, and experienced a total loss of power. The pilot set up for a forced landing on a golf course. After touchdown, he applied maximum braking before the airplane struck a wooden fence, then a brick pillar and metal pool fence, resulting in damage to the fuselage and both wings. Both occupants egressed without injury.
Post-Accident Examination
The airplane was recovered to a salvage facility. An engine examination was conducted by an airframe and powerplant (A&P) mechanic under oversight of a Federal Aviation Administration inspector. The engine showed no evidence of impact damage, and all components were present. No evidence of any preimpact mechanical malfunctions or failures was observed.
Fuel samples were taken: one from the carburetor bowl appeared cloudy with a greenish-yellow tint; a second from the fuel supply hose was clear with a blue tint; a third from the main gascolator sump was clear with blue tint. The electric fuel boost pump functioned normally, and its internal filter screen was clean. The mechanical fuel pump produced suction on the inlet side when the crankshaft was rotated manually. The source of the fuel contamination was not determined.