Collision en vol entre Ventus CM et ASH 26E près de Bütthard entraîne des décès

Le 16 juillet 2006, une collision en vol s'est produite près de Bütthard, en Allemagne, impliquant un Schempp-Hirth Ventus CM et un Alexander Schleicher ASH 26E. Les deux planeurs motorisés volaient dans des conditions thermiques lorsqu'ils sont entrés en collision à environ 1000 mètres au-dessus du sol. La collision a entraîné la destruction des deux appareils et la mort des deux pilotes. Le Ventus CM s'est écrasé sur des lignes électriques et a pris feu, tandis que l'ASH 26E a percuté le toit d'un bâtiment résidentiel. L'enquête n'a révélé aucun défaut technique sur les appareils, et la collision n'a pas été observée par les pilotes.

1. Cross-country thermaling: The Ventus CM departed Mannheim for a cross-country soaring flight and was cruising with the engine retracted while using thermals in visual meteorological conditions.
2. Shared thermal use: Both motor gliders were circling or climbing in the same thermal updraft near Bütthard at about 1000 m above ground, creating a risk of conflict in close proximity.
3. Limited visual detection: Despite good weather, the pilots did not visually detect each other in time, indicating human see-and-avoid limitations without additional onboard collision warning aids.
4. Unseen opposing traffic: The Ventus CM and the ASH 26E approached each other on nearly opposite headings within the thermal without either pilot recognizing the developing collision course.
5. Frontal mid-air impact: The left wing of the Ventus CM struck and severed the cockpit area of the ASH 26E near its wing–fuselage junction, tearing off the Ventus’s left wing and fatally injuring the ASH pilot.
6. Uncontrolled descents: With the ASH 26E cockpit destroyed and the Ventus CM missing its left wing, both aircraft entered uncontrolled descents; the ASH 26E fell onto a house roof while the Ventus CM fuselage fell into an overhead power line and burned.
7. Crash - fatal: Both motor gliders were destroyed and both pilots were fatally injured, with additional damage to residential buildings and power lines on the ground.