What happened
On July 20, 2007, a Centrair C 101 A glider, registration F-CGFT, was performing a winch launch from the Bagnères-de-Luchon aerodrome. During the acceleration phase of the takeoff, the pilot attempted to pull the aircraft into a 30-degree climb. Despite significant physical effort on the control column, the aircraft failed to gain altitude.
Faced with the lack of climb, the pilot elected to release the cable and proceed with an emergency landing. Upon release, the cable parachute deployed and drifted to the left, causing the left wing to strike the cable. This impact induced a left yaw, leading to a nose-over (ground loop) during the landing roll. The aircraft came to a stop before reaching the midpoint of the runway, resulting in heavy damage to the fuselage and a broken tail boom.
The investigation
The investigation focused on the mechanical configuration of the aircraft and the procedures used during the launch. On this specific model, the towing hook is located under the fuselage, directly beneath the instrument panel, while the winch hook is located within the landing gear well and is much harder to access.
Investigators found that the ground assistant had recently performed a launch using a different aircraft type, a Twin Astir, where the towing hook is located at the nose and the winch hook is under the fuselage. It was determined that the assistant had mistakenly used the forward towing hook of the F-CGSS instead of the winch hook. Because the cable was anchored far forward of the center of gravity, the resulting pitch-down moment prevented the aircraft from achieving the necessary climb angle.
Findings
- The primary cause of the launch failure was the confusion between the towing hook and the winch hook.
- The ground assistant had used the incorrect attachment point due to recent experience with a different aircraft configuration.
- The assistant lacked specific training in glider operations and was not a trained flight instructor or starter.
- The pilot was unable to visually verify the hook attachment from the cockpit during the pre-launch phase.