What happened
Prior to 11:00, the pilot arrived at the Mexia-Limestone County Airport (TX06) in Mexia, Texas. After the pilot boarded the Duke 60, an acquaintance assisted by closing and securing the cabin door. Following the engine start, the aircraft remained stationary on the ramp for approximately 10 to 15 minutes. While the pilot was not observed taxiing to the runway, the aircraft subsequently moved to the northern end of Runway 18 to begin a downwind takeoff toward the south.
The aircraft's path following the accident was found to be consistent with the extended centerline of Runway 18, traveling on a 183-degree bearing. The wreckage was located near a fence line, roughly 0.25 miles from the runway's departure end. A significant burn area was identified both before and surrounding the debris field along the wreckage trail.
Findings
An inspection of the cockpit area revealed that a 9/16-inch hex-head bolt had been placed into the control lock pinhole of the control column. This condition contradicted the standard operating procedures outlined in the Duke 60 Airplane Flight Manual. Specifically, the preflight inspection instructions require the removal and stowing of control locks, and the before-start checklist mandates a verification of the freedom of movement and proper response of all flight controls.