What happened
The pilot was operating the aircraft on a local flight following the completion of a glider tow operation. While maneuvering within the airport traffic pattern to return to the runway, the elevator control system suddenly seized. This mechanical failure rendered the pilot unable to manage the aircraft's descent rate or pitch attitude. Unable to recover from the uncontrolled dive, the airplane descended rapidly and impacted a line of trees.
The investigation
Following the accident, investigators conducted a detailed examination of the wreckage to determine the root cause of the control failure. The inspection revealed that the elevator control cables had failed in the vicinity of a pulley mechanism. This structural failure of the cable system was identified as the primary reason for the loss of pitch control during the critical phase of flight.
Findings
The investigation highlighted several contributing factors related to maintenance and mechanical integrity. The aircraft had undergone its last scheduled inspection 75 hours prior to the accident, which may have allowed for undetected wear or fatigue in the cable system. The failure occurred near a pulley, suggesting potential issues with cable routing, tension, or component wear that led to the catastrophic breakage.
Safety message
Regular and thorough inspections of flight control cables are critical for maintaining aircraft safety. Mechanics should pay close attention to pulley systems and cable integrity to prevent failures that can lead to a loss of control.