Ka-2b Kollision mit Seil in der Nähe von Schafberg, Pontresina, Schweiz

Am 5. August 1963 kollidierte eine Ka-2b Rhönschwalbe mit einem Seil einer Materialseilbahn in der Nähe von Schafberg, Pontresina, Schweiz. Der Vorfall ereignete sich kurz nachdem das Segelflugzeug in etwa 250-300 Metern über dem Flugplatz Samedan ausgeklinkt wurde. Das Seil, Teil einer Seilbahn zur Lawinenkontrolle, war nicht markiert und schwer vor dem Hintergrund des Berges zu erkennen. Trotz der Kollision blieben beide Insassen unverletzt, obwohl das Segelflugzeug zerstört wurde und die Seilbahn geringfügigen Schaden erlitt.

1. Aerotow ridge entry: The Ka-2b launched by aerotow from Samedan and was towed directly into the Val Bernina along the valley-side slopes at heights in places well below the standard 150 m minimum over the terrain.
2. No obstacle briefing: Before the flight, neither the instructor nor the student reviewed the posted local obstacle chart, so the existence and approximate position of the Pontresina–Schafberg material cableway remained unknown to them.
3. Low ridge flight height: During the tow into the valley and along the slopes, the tug and glider operated at relatively low height above the hillside, reducing vertical clearance from any unseen obstacles.
4. Tow release near Schafberg: At about 250–300 m above Samedan, near the lower Schafberg slope opposite Pontresina, the instructor released from tow to continue independent ridge soaring in what he believed was a steady 3 m/s updraft.
5. Closer ridge approach: After release, the instructor slightly reduced airspeed and flew the glider closer to the Schafberg slope, maintaining more than 50 m clearance from the ground but without awareness of any overhead cables.
6. Cable impact and spin: With the cable still unseen by the instructor and only noticed moments before by the student, the left wing struck the unmarked ropeway support cable, causing the glider to yaw and roll left and enter a spinning descent into the trees.
7. Crash - no injury: The glider fell through approximately 20 m high larch trees to the ground and was destroyed, while both occupants remained uninjured and the ropeway sustained only minor damage.