On August 13, 1990, a Piper PA-25-235 (registration N7316Z) operated by Kuehn's Aerial Spraying, Inc. was involved in an aviation accident near Parshall, ND. Investigators recorded the probable cause as: The pilot's inadvertent selection of the engine mixture control instead of the spray tank system, which resulted in a loss of engine power and a subsequent hard landing. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
An aerial applicator pilot inadvertently secured the engine mixture instead of the spray tank system during a return flight, resulting in a hard landing in a wheat field.
What happened
The incident occurred while an aerial applicator was returning to its base after completing a spraying job. Upon seeing a previously sprayed field that the pilot believed required one additional swath run, he decided to make another pass. During this maneuver, the pilot inadvertently secured the engine mixture control instead of operating the spray tank system. The loss of engine power resulted in a forced landing. The aircraft impacted an adjacent wheat field with significant force, resulting in a hard landing.
Findings
The primary factor contributing to the accident was the pilot's inadvertent selection of the wrong control. By securing the engine mixture rather than the spray system, the pilot caused an immediate loss of power during low-altitude operations. This error left insufficient altitude and airspeed to recover from the situation, leading directly to the hard landing in the adjacent agricultural field.
Probable cause
The pilot's inadvertent selection of the engine mixture control instead of the spray tank system, which resulted in a loss of engine power and a subsequent hard landing.