Ayres S2R N29254 accident near Glenn, California

Probable cause

Loss of engine power for reasons that could not be determined because postaccident examination of the airframe and engine did not reveal any anomalies that would have precluded normal operation.

NTSB analysis

While on approach to spray a field, the pilot observed smoke emanating from the engine compartment. He set up for an emergency landing to a road. During the landing roll, the airplane veered off the road and struck power poles. During a postaccident examination of the engine, no mechanical anomalies were found that would have precluded normal operation. The manufacturer noted that the overall condition of the engine exhibited corrosion and heat erosion. The fuel nozzles were covered in a soot and soil combination. When flow tested, the fuel nozzles exceeded the parameters in the component maintenance manual test procedures. The manufacturer stated that the out-of-limit condition may cause hot-section deterioration over time but would not have prevented normal engine operation. The compressor turbine guide vane ring was examined, and blade fractures from overstress were found, along with chipping and flaking of the coating adjacent to the fracture surfaces.

Text from the NTSB. Open the NTSB docket for WPR10LA247 for the full record.