Event Description
According to the pilot, as the airplane accelerated for takeoff, the landing gear rolled over a rut in the runway surface, causing the airplane to bounce. During the bounce, the pilot reported that his seat moved rearward, and he could not reach the flight controls, resulting in a loss of control. The airplane subsequently veered off the left side of the runway and collided with trees.
Runway Condition
An examination of the runway surface revealed that the clay and gravel runway had ruts in the center of the takeoff area. These ruts were present at the location where the airplane's landing gear made contact during the takeoff roll.
Seat Assembly Examination
The airplane seat assembly was examined after the accident. The examination found that both the seat rails and the seat locking pins were in serviceable condition, indicating that the seat movement was not due to mechanical failure of the locking mechanism.