Collision d'un Standard Libelle 201 avec un câble près de Rigi-Kulm entraîne un décès

Le 5 juin 1983, un Glasflügel Standard Libelle 201 est entré en collision avec un câble de téléphérique près du sommet de Rigi-Kulm, en Suisse. Le planeur effectuait un vol d'entraînement depuis l'aérodrome de Buttwil dans des conditions météorologiques favorables. Vers 15h50, heure locale, l'appareil a percuté le câble à 250 mètres au sud-est du sommet du Rigi, provoquant son crash sur une pente raide. Le pilote a subi des blessures mortelles et le planeur a été détruit. L'enquête officielle a confirmé que le pilote n'a pas maintenu l'altitude minimale de vol, entraînant la collision.

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.