Collision du Speed Astir II avec un câble de transport au Stanserhorn, Suisse

Le 5 juin 1983, un Grob Speed Astir II participait à un vol de compétition au départ de Lucerne-Beromünster. En tentant de prendre de l'altitude au-dessus du Stanserhorn, le pilote est entré en collision avec un câble de transport. Le planeur s'est écrasé dans une forêt, entraînant de graves blessures pour le pilote et des dommages importants à l'appareil. Le câble de transport est resté intact et aucun dommage significatif à des tiers n'a été signalé. L'enquête a confirmé la collision avec le câble comme cause de l'accident.

1. Aerotow competition start: The pilot aerotowed from Luzern-Beromünster at 14:36 local time to begin a regional competition triangle task Beromünster–Sörenberg–Engelberg–Beromünster.
2. Poor lift en route: On the leg toward the first turnpoint Sörenberg, the pilot encountered only sinking air in the Pilatus area, forcing him to fly much lower than originally planned.
3. Low-altitude cable area: Despite prior briefing warnings about cable hazards and the presence of many transport cables in the area, the pilot continued flying low in terrain where such obstacles were known to exist.
4. Did not abandon task: The pilot lacked the determination to abandon the competition flight early despite deteriorating soaring conditions and increasing risk near terrain and cables.
5. Low climb attempt Stanserhorn: Seeking to regain altitude, the pilot diverted to the west side of Stanserhorn and flew along the slope searching for lift at about 60 m above ground.
6. Collision with cable: While flying with approximately 19° left bank along the Stanserhorn slope, the glider’s left wing struck a transport cable, cutting into the leading edge.
7. Crash - serious injury: Following the cable strike, the glider entered a left turn and crashed into a forest, severely injuring the pilot and heavily damaging the aircraft, while the cable remained intact.