What happened
The aircraft was engaged in aerial application of agricultural chemicals in the vicinity of Swea City, Iowa. According to the pilot in command, the flight phase involved making a procedure turn following the completion of a spray swath. During this maneuver, the aircraft experienced an aerodynamic stall. The loss of lift resulted in an uncontrolled descent directly into the field that had previously been treated.
The pilot reported that there were no prior indications of flight control problems or engine power loss during the turn. Despite the incident, the pilot did not file an official accident report with the relevant authorities.
Findings
The primary factor in this event was the stall during a low-altitude maneuver. The stall occurred while the aircraft was turning, likely due to excessive angle of attack or insufficient airspeed for the configuration at that moment. No mechanical failures were cited by the pilot as contributing factors.