Incident Overview
A flight instructor reported that during the landing roll, a student pilot attempted to correct the airplane from drifting to the right by applying left rudder. The rudder input was unresponsive, and the airplane continued to drift to the right, departing the runway. The airplane then looped to the right and came to rest on the right side of the runway, sustaining substantial damage.
Examination Findings
Examination of the airplane revealed that the left rudder cable had failed. Detailed optical examination of the fractured individual wire ends and strands adjacent to the fracture showed significant wear damage. At the cable separation point on the left side of the fuselage, wear marks were found on the upper, outboard seatback support bar.
Seat Frame Repair
The seat was removed from the airplane, revealing that the seat frame had been repaired on the left side. The weld extended the seatback support bar down and aft, preventing it from aligning with the lower seat support bar. This extension entered the travel path of the left rudder cable.
Additional Systems Check
An examination of the remaining airplane systems revealed no anomalies.