What happened
On June 30, 2009, at 16:05, a single-seat Grob G 102 Astir CS Jeans, registration F-CADQ, was performing a local flight near the Orléans Saint-Denis-de-l’Hôtel airfield. After being towed and releasing at an altitude of 550 meters, the pilot entered a spiral descent over the airfield, eventually reaching 800 meters.
Seeking lift, the pilot targeted a single visible cumulus cloud located south of the airfield. Upon reaching the cloud at approximately 350 meters, the pilot was unable to gain further altitude. As the altitude dropped to 200 meters, the pilot determined that returning to the airfield was no longer possible and decided to perform an off-field landing.
Initially, the pilot selected a 500-meter long field oriented toward the west. However, during the approach, the presence of two high-voltage power pylons within that field forced a change in plans. The pilot redirected the approach toward a cornfield to the right, oriented toward the north. During the final approach, at an altitude of 70 meters, the pilot realized the aircraft was too high and deployed the air brakes. While attempting to turn at the end of the field to land in the opposite direction, the right wing struck the ground, causing the glider to skid on its belly. The aircraft was destroyed.
The investigation
Investigators utilized the aircraft's onboard logger to reconstruct the flight trajectory. The analysis revealed that the pilot had exceeded the permitted local flight boundaries. The local flight volume is defined by a cone centered on the airfield, tilted toward the wind direction. When the pilot reached the cumulus cloud, they were 5 km from the airfield at an altitude of 350 meters; to remain within the authorized local flight cone, a minimum altitude of 500 meters was required.
Furthermore, the investigation established that while the pilot had held local flight authorization for approximately one year, they were not authorized for off-field landings. The pilot's intention had been to practice searching for thermals within the local volume to eventually qualify for off-field flight operations. The pilot's standard practice had always been to land at the Saint-Denis-de-l’Hôtel airfield.
Findings
- Erroneous estimation of local flight boundaries, leading the pilot to fly outside the authorized flight volume.
- Improvised off-field landing technique, specifically the decision to perform a turn at the end of the field which resulted in the wing strike.
- The pilot's lack of authorization for off-field landings and the decision to attempt a landing in a cornfield after encountering obstacles in the primary choice.