What happened
On May 2, 2008, a Glasfugel H201 B glider, registration F-CELH, was performing a local flight at the Arnage airfield in France. The aircraft was being operated via a towed takeoff on an unpaved runway. Shortly after the takeoff roll reached approximately 20 meters, the pilot reported abnormal aircraft behavior. The tow plane pilot responded by returning to the airfield circuit. While flying in a downwind pattern, the glider pilot released the tow cable. Following the release, the glider entered an uncontrolled spin and struck the ground within an industrial park area. The accident resulted in one fatality and the destruction of the aircraft.
The investigation
Investigators examined the wreckage and found that the cockpit and forward section of the glider had struck the ground at a steep nose-down angle. The fuselage had broken into pieces, and the right wing was completely separated from the wreckage. While the elevator and rudder controls remained continuous, investigators discovered that the left and right aileron controls had become disconnected at the junction where the control rods meet the aileron linkages.
Specifically, the assembly consisting of a pin and ball joint was found to be unengaged. Testing confirmed that if these pins are not properly inserted into the ball joints, the ailerons can move to a full-down position under aerodynamic loads.
Regarding the aircraft's maintenance history, the investigation revealed that approximately two weeks prior to the accident, a maintenance official had performed a repair on a fuselage reinforcement frame. This repair required the removal of the wings. Because this was an informal demonstration of the repair to a successor rather than a formal maintenance procedure, there was no record of whether the aileron control reconnection had been verified. Furthermore, the club's chief pilot was unaware that this specific intervention had taken place.
Findings
- The primary cause of the accident was the failure to properly re-engage the aileron control pins following a technical intervention on the aircraft.
- The aileron control linkages were likely left uncoupled during the reassembly of the wings after the recent fuselage repair.
- Necessary safety inspections and verification flights following the technical work were likely not performed.
- The pilot was unable to maintain control of the aircraft due to the loss of aileron functionality, leading to the fatal impact.