What happened
On May 23, 2004, during a soaring competition at the Chambéry Challes-les-Eaux airfield, a Schleicher ASW 22 glider was performing a winch takeoff. To accommodate a high frequency of departures, a second winch had been installed alongside the first. As the pilot began the takeoff roll on runway 33, the left wing of the aircraft drifted approximately five meters off the runway centerline.
During this lateral deviation, the glider snagged a third cable that was lying on the ground near the takeoff area. The starter, observing the incident, radioed to the pilot that two cables were being pulled away. However, the pilot elected to continue the winch ascent. At an altitude of approximately 300 meters, the automatic release mechanism functioned, but the pilot reported being hooked to an object. Attempting to avoid tensioning the cable and return to the airfield, the pilot executed a steep dive. During the subsequent landing attempt, the cable acted as a sudden brake, causing the glider to strike the runway hard at a 15-degree nose-down attitude. The aircraft sustained heavy damage.
The investigation
The investigation examined the positioning of the cables, the aircraft's weight distribution, and the decision-making processes of both the pilot and the starter. Investigators found that the cables for subsequent takeoffs were laid out on the ground near the takeoff path, providing insufficient safety margins.
Regarding the aircraft's stability, the investigation revealed that the glider was heavily loaded with water ballast. An individual assisting with the takeoff held the left wing to keep it level but released it once the takeoff roll began. Because this person was unaware of the specific handling requirements of a ballasted glider, they did not inform the pilot that the wing was difficult to stabilize. This allowed the water ballast to shift, causing the wing to drop and the aircraft to veer toward the cables.
Findings
- The placement of the spare cables on the ground created a significant hazard if the aircraft deviated from the runway centerline.
- The pilot failed to follow established safety instructions, which mandated releasing the cable if a wing touched the ground during takeoff.
- The pilot's decision to continue the takeoff was influenced by the belief that landing in the ruts created by cable-towing vehicles would damage the heavily loaded aircraft.
- The lack of rigor in flight preparation and the failure to apply safety procedures during the competition takeoff were the primary contributing factors.
- The starter did not intervene via radio to abort the takeoff, assuming the experienced pilot would manage any issues independently.