What happened
The pilot reported making a smooth touchdown approximately halfway down runway 21 (2,350 X 100) at the O'Neal Airport in Vincennes, Indiana. Shortly after the aircraft touched down, it encountered a rough spot on the runway surface. This impact caused the airplane to bounce back into the air, at which point the tail began to shift.
During this period, the pilot was occupied with maintaining directional control and was unable to apply the brakes. As a result, the airplane veered to the right and departed the runway, entering an adjacent wheat field. While the aircraft's speed decreased during the excursion, it came to a sudden stop and underwent a slow nose-over onto its back.
The investigation
A mechanical examination of the airplane was conducted following the accident. The inspection revealed no anomalies in the aircraft's condition.