On August 21, 1984, a Piper PA-25-235 (registration N6474L) operated by William A Christenson was involved in an aviation accident near Shelley, ID. Investigators recorded the probable cause as: The engine failure could not be determined due to the destruction of the aircraft and powerplant. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
An agricultural aircraft experienced an engine failure while en route to spray a field, resulting in a forced landing into an irrigation pivot and a post-crash fire.
What happened
The pilot was operating an agricultural aircraft for crop dusting duties when the engine began to run roughly. The pilot decided to divert to a nearby agricultural strip to land safely. However, the engine ceased operation before the aircraft could reach the designated landing area. During the subsequent forced landing, the airframe struck an irrigation pivot structure. A post-crash fire consumed the aircraft entirely.
Findings
The investigation was limited by the destruction of the powerplant and the absence of mechanical anomalies prior to the failure. Engine failure occurred without a determinable cause. The pilot's decision to divert to an agricultural strip demonstrates appropriate emergency response, but the proximity of ground obstacles contributed to the severity of the impact.
Safety message
Agricultural pilots should maintain awareness of terrain and obstacles in diversion areas. Pre-flight inspections and engine monitoring are critical for early detection of performance issues.
Probable cause
The engine failure could not be determined due to the destruction of the aircraft and powerplant.