What happened
On August 3, 2000, a Cessna FA 150 L was conducting a training flight from Hildesheim to Braunschweig. After completing a successful landing and a subsequent go-around, the crew entered a right-hand pattern. During the right base leg, the flight instructor noticed difficulties operating the rudder pedals.
As the aircraft approached the grass runway 26 at approximately 600 ft, the student pilot discovered that the rudder had become jammed in a full left position. The instructor took control and attempted to maintain the approach centerline by applying full opposite aileron to induce a sideslip. Despite these efforts, the aircraft touched down approximately 30 m south of the grass runway. The aircraft then veered in a circular arc across a concrete apron, with the tail striking the ground multiple times. The excursion ended when the aircraft collided with an airport perimeter fence. The accident resulted in no injuries, but the aircraft sustained heavy damage to the engine, engine mounts, nose gear, and both wings.
The investigation
The BFU examined the wreckage on-site to determine the cause of the rudder malfunction. Investigators identified a fracture in the fuselage skin near the end plate. An aluminum reinforcement plate, which held an eye bolt for securing the aircraft, had been bent backward by approximately 100 degrees. This deformation caused the rudder to strike the plate, locking the control surface in the left position.
Analysis of the metal revealed that a portion of the fuselage skin had suffered a fracture some time prior to the accident, but this damage was hidden beneath the reinforcement plate. Furthermore, the investigation found that the eye bolt had been subject to multiple previous ground contacts, which had contributed to the structural degradation. While the student pilot had performed a pre-flight inspection, the underlying structural failure was not visible during a standard visual check.