Air Tractor Inc AT 602 N4257R accident near Cash, Arkansas

Probable cause

The pilot's incapacitation due to a cardiac event, which resulted in a loss of airplane control.

NTSB analysis

The commercial pilot was conducting his sixth agricultural load application of the day. Witnesses observed the airplane make a low-altitude turn and subsequently enter a spin with a nose-low attitude . The airplane subsequently impacted a rice field adjacent to the field being treated.

Postaccident examination of the airframe, engine, and propeller revealed no evidence of any preimpact mechanical malfunctions or anomalies that would have precluded normal operation.

The pilot's autopsy revealed that he had severe coronary artery disease with evidence of associated heart muscle injury. No evidence was found indicating that the pilot was aware of his health issues. The coronary artery disease increased the pilot's risk of a cardiac event, which would have resulted in shortness of breath, dizziness, lightheadedness, or an irregular heart rhythm (arrhythmia) with decreased cardiac output and loss of consciousness. The combination of the normal stress associated with low-altitude maneuvering and decreased cardiac output likely resulted in a sudden decrease of blood flow to the brain and the pilot's incapacitation, which resulted in his loss of airplane control.

Text from the NTSB. Open the NTSB docket for CEN17FA259 for the full record.