Overview
On August 13, 2018, at about 1815 central daylight time, an Air Tractor 602 airplane, registration N629LA, sustained substantial damage in an accident near Bismarck, Illinois. The commercial pilot, who was operating the flight under Title 14 Code of Federal Regulations Part 137 for aerial application, sustained serious injuries. First responders transported the pilot to a hospital.
Witness Account
An agricultural pilot who witnessed the event reported seeing the airplane maneuvering at low altitude over a corn field before it appeared to enter a flat spin. The airplane then impacted the ground.
Wreckage Examination
The wreckage was found upright in the field. Ground scars were consistent with a wings- and nose-level impact attitude. The rudder was located about 50 feet northwest of the main wreckage. The fuselage sustained severe damage to all components forward of the cockpit area. The firewall, main landing gear attachments, and hopper were crushed and segmented by impact forces, remaining loosely attached. The aft fuselage exhibited crumpling between the cockpit and vertical stabilizer.
Flight Controls
All flight control surfaces were present with the main wreckage, and continuity was established from the cockpit to the surfaces. The flap actuator was extended about 1 inch, corresponding to a 7° flap extension. The flap torque tube was continuous to the flap arms on both sides. The airplane was not equipped with an elevator down-spring or rudder-aileron interconnect system. According to the manufacturer, these systems were required and increased the airplane's stability and handling characteristics.
Propeller
The propeller remained attached to the engine, with all five blades found near the engine. Two blades were fractured near the root and buried in soil. The visible blades showed chordwise scoring and leading edge abrasion, consistent with rotation at impact.