What happened
On 23 May 2021, a Cessna 172 (registration F-GCNK) was performing a cross-country flight near Libourne - Artigues-de-Lussac, France. After completing initial circuits at Bordeaux-Yvrac, the pilot proceeded to the Libourne aerodrome to conduct training. During the final turn for runway 22, the aircraft lost control and entered a steep left bank. The aircraft descended approximately 500 feet before striking an oak tree and colliding with the ground. The impact resulted in the death of the pilot and the destruction of the aircraft.
The investigation
The investigation focused on the mechanical state of the aircraft's flight controls and the pilot's recent flight history. Investigators examined the wreckage, which was found in a hedge near a local road. While the aircraft's elevators, rudder, and flaps remained intact, the investigation identified a significant anomaly in the roll control system. Specifically, the chain of the interconnection loop connecting the two control wheels was found to be open at the pilot's side.
Technical examination of the yoke revealed that the left section was heavily distorted. The chain used to link the two control wheels showed clear evidence of surface corrosion, and the pin connecting the links had broken due to a sudden overload. Investigators also consulted the manufacturer, Textron Aviation, regarding the implications of such corrosion on aileron functionality.
Findings
- The aircraft was in a steep left bank with a slight nose-down attitude at the moment of impact.
- The aileron control chain exhibited extensive corrosion, which could have caused stiff control movement or weakened the pins holding the links together.
- While the broken pin on the chain was caused by an overload, investigators could not definitively rule out whether the chain opened during flight or as a result of the impact.
- If the chain opened in flight, the loss of tension in the interconnection loop could have prevented the pilot from executing unrestricted aileron inputs, potentially leaving the ailerons positioned in a way that prevented recovery.
- The aircraft had undergone a 200-hour inspection only weeks prior to the accident, but the specific tasks related to the aileron control system were not explicitly detailed in the recent maintenance logs.