Accident Summary
On August 7, 2020, about 1036 eastern daylight time, a Cessna P210N, registration N6300W, was destroyed when it impacted terrain and caught fire near Allendale, South Carolina. The pilot and passenger were seriously injured. The flight was operated as a personal flight under Title 14 Code of Federal Regulations Part 91.
Pilot Account
The pilot reported departing Gainesville Regional Airport (GNV), Gainesville, Florida, around 0830, with an intended destination of Allendale County Airport (AQX), Allendale, South Carolina. Prior to departure, he added 58 gallons of fuel. During the preflight, he observed "a flake or two of black gunk" when sumping the right-wing fuel tank, but continued until the fuel appeared clean. The flight was uneventful until, on short final approach to runway 35 at AQX, the engine experienced a total loss of power. The propeller continued to rotate, and the pilot attempted to restart the engine by switching fuel tanks, but was unsuccessful. Realizing the airplane would not reach the runway, he performed a forced landing to a field. During the landing, the airplane struck trees and impacted the ground. After impact, the pilot and passenger egressed, and a postimpact fire ensued.
Engine Examination
An NTSB investigator examined the engine. The propeller could be rotated through 360°, confirming crankshaft and valvetrain continuity. Compression was obtained on all cylinders, and spark plugs exhibited normal wear. The magnetos were removed and found to have melted internal components. The oil sump and pickup screen showed no metallic particles. The turbocharger turned freely with no anomalies. The engine-driven fuel pump had thermal damage. The fuel inlet screen to the throttle body was removed and found occluded with debris. The fuel manifold was disassembled with no anomalies. Fuel injectors from cylinders No. 3 and No. 5 had blockages. The fixed-base operator where the airplane refueled reported 58 fueling events and 1,759.58 gallons of 100LL aviation fuel distributed without any reported fuel issues in other aircraft.
The engine had been installed on the airframe about 8 flight hours before the accident. An overhaul was completed on May 14, 2020, following a bird strike in December 2019. During that overhaul, the fuel system was also overhauled, including installation of an overhauled throttle control/throttle body. After overhaul, an engine test run at multiple RPM settings showed no anomalies, and the engine was approved for return to service.
The throttle body fuel inlet screen and debris were sent to the NTSB Materials Laboratory. Examination using Fourier Transform Infrared spectroscopy identified the debris as polyethylene terephthalate (PET), a thermoplastic polymer commonly used in fuel system components.
Background
The pilot reported that the right wing had "a little bit of black junk" in the fuel when sumped "from time to time." The mechanic who performed the most recent engine maintenance stated he did not note any issues when installing the engine, and the pilot did not mention the fuel contamination issue until after the accident.