What happened
The pilot initiated the takeoff roll on the runway. As the aircraft accelerated to rotation speed, the pilot's seat unexpectedly slid backward along its tracks. This sudden movement occurred just before the airplane was intended to lift off the ground. The shift in position caused the pilot to lose directional control of the aircraft. Unable to maintain the runway centerline or altitude, the airplane departed the paved surface and collided with an embankment adjacent to the runway.
The investigation
Post-accident examination of the aircraft focused on the seat mechanism. Inspectors analyzed the seat tracks for signs of mechanical failure or wear that might explain the movement. The inspection revealed no elongation of the seat track holes, which would have indicated excessive wear or stretching over time. This finding suggested that the slide was not due to structural degradation of the mounting hardware.
Findings
The investigation highlighted a critical procedural lapse. The aircraft's operating manual includes a "Before Starting The Engine" checklist item that explicitly requires the crew to adjust and lock the seats and seat belts. The failure to secure the seat prior to engine start allowed it to slide during the high-vibration phase of takeoff. This mechanical shift directly contributed to the pilot's inability to control the aircraft during the critical rotation phase.
Safety message
Pilots must strictly adhere to pre-flight checklists, particularly those governing cockpit setup. Ensuring that all seats are properly adjusted and locked before engine start is essential for maintaining full control of the aircraft during takeoff and flight operations.