Standard Libelle 201 Kollision mit Seil nahe Rigi-Kulm führt zu Todesfall

Am 5. Juni 1983 kollidierte ein Glasflügel Standard Libelle 201 mit einem Seilbahnseil in der Nähe des Gipfels von Rigi-Kulm, Schweiz. Das Segelflugzeug befand sich auf einem Trainingsflug vom Flugplatz Buttwil bei günstigen Wetterbedingungen. Gegen 15:50 Uhr Ortszeit traf das Flugzeug das Seil 250 Meter südöstlich des Rigi-Gipfels, was zum Absturz an einem steilen Hang führte. Der Pilot erlitt tödliche Verletzungen, und das Segelflugzeug wurde zerstört. Die offizielle Untersuchung bestätigte, dass der Pilot die Mindestflughöhe nicht einhielt, was zur Kollision führte.

1. Aerotow training flight: The experienced pilot took off by aerotow from Buttwil at 14:27 for a local training soaring flight in good weather conditions.
2. Ridge soaring near Rigi: After release at about 1300 m MSL, the glider proceeded to the Rigi area and was later seen flying at relatively low height along the north side of Rigi-Kulm.
3. Poor cable visibility: In the late afternoon lighting the unmarked goods cableway wires on the northeast flank of Rigi were very hard to see against the dark rock and shaded terrain.
4. Busy local airspace: At the time of the accident at least one other glider, three hang gliders, and a low-flying powered aircraft were in the Rigi-Kulm area, potentially distracting the pilot.
5. Minimum height undershot: While ridge soaring along the slope, the pilot descended below the prescribed 60 m minimum height above ground, placing the glider in the height band of the cableway support wire.
6. Collision with cable: At about 15:50 the glider, in straight and nearly level flight, struck the 18 mm carrier cable of the goods cableway approximately 3.77 m inboard of the right wingtip at 1725 m MSL, 250 m southeast of Rigi-Kulm.
7. Crash - fatal: Following the cable strike the damaged glider tumbled down a steep rocky slope for about 110 vertical meters, was destroyed, and the pilot sustained fatal injuries.