Primary finding
Probable cause
A total loss of engine power due to fuel contamination from an undetermined source.
Investigator assessment
Analysis narrative
The pilot reported a loss of engine power about 7 miles from the destination airport and about 500 ft above ground level (agl). He executed a forced landing to a pasture, during which the airplane impacted a fence. The airplane sustained substantial damage to both wings. Postaccident testing of fuel samples from the airframe and engine fuel filters exhibited a brown tint. The airframe fuel filter sample also appeared to contain some minor debris. Analysis of the fuel samples for corrosiveness and water-soluble components were within the specification. However, due to small sample volume from the filters, testing for volatility and contaminants could not be completed. A postaccident engine test run, conducted with clean fuel provided directly to the engine, revealed no engine-related anomalies. While it seems likely that the engine lost power due to fuel starvation resulting from contamination, the nature and source of that contamination could not be determined.
Source record
Factual narrative
On July 26, 2024, about 1313 central daylight time, an Ayres S2R-G6 airplane, N6136Z, was substantially damaged when it was involved in an accident near Alliance Municipal Airport (AIA), Antioch, Nebraska. The pilot was not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 positioning flight. The pilot reported that when the airplane was about 7 miles from the destination airport, about 500 ft agl, the engine exhaust gas temperature and torque decreased to zero. The engine did not respond to an increase in the throttle, and he executed a forced landing to a pasture in an unpopulated area. The airplane impacted a steel fence during the landing and sustained substantial damage to both wings. Fuel was present in the fuel tanks at the time of a postaccident examination. Fuel samples taken from each fuel tank were clear. However, a fuel sample from the airframe fuel filter exhibited a brown tint with minor debris, and a fuel sample taken from the engine fuel filter exhibited a brown tint with no obvious debris. Due to the small sample volume for the fuel filters, volatility and contaminants testing could not be completed. However, testing for corrosiveness and water-soluble components were within specifications. Additionally, a postaccident engine test run was conducted at the accident site with clean fuel provided directly to the engine. The engine started smoothly and ran without any anomalies observed.