Aviat Aircraft Inc A-1C-200 N382US accident near Jiggs, Nevada

Probable cause

An engine anomaly for reasons that could not be determined, which resulted in a precautionary landing in deep snow and a subsequent noseover.

NTSB analysis

The private pilot reported that, about 10 minutes after departing for a personal, local flight and when the airplane was about 1,000 ft above ground level, the engine began running roughly, and the rpm surged several times despite the engine monitoring gauges all indicating normal operation. The pilot chose to make a precautionary landing on a snow-covered dirt airstrip. The pilot reported that, after reducing power to land, he did not recall the engine experiencing further roughness or surging. During the landing roll, the airplane nosed over in the deep snow and then came to rest inverted.

During postaccident test runs, the engine ran normally through various power settings with no anomalies noted that would have precluded normal operation. The reason for the engine momentarily running roughly and surging could not be determined.

Text from the NTSB. Open the NTSB docket for WPR17LA062 for the full record.