Collision en vol entre S 18 II et Bergfalke II près de Muottas Muragl, Suisse
Le 27 juillet 1959, deux planeurs, un AG Wynau S 18 II et un Scheibe-Flugzeugbau GmbH Bergfalke II, sont entrés en collision en vol près de Muottas Muragl, Suisse. La collision s'est produite à environ 2500 mètres d'altitude, entraînant le crash du Bergfalke II et la mort des deux occupants. Malgré des dommages importants, le pilote du S 18 II a réussi à atterrir à l'aérodrome de Samedan. L'enquête a conclu qu'une observation inadéquate de l'espace aérien par les deux pilotes a conduit à la collision.
- Winch launch ridge soaring: Both gliders HB-559 and HB-219 were winch-launched from Samedan and climbed in the ridge lift at Muottas Muragl, flying repeated passes near the Muottas-Kulm hotel.
- High-traffic ridge area: The Muottas Muragl area near Samedan was a popular alpine soaring site with strong lift and frequent glider traffic, increasing the need for vigilant lookout.
- Converging flight paths: HB-219, having previously seen HB-559 70–80 m above while flying down-valley, turned left back toward Muottas Muragl at about the same time HB-559 flew a wide left turn back over the hotel, placing the aircraft on opposing headings.
- Inadequate lookout: Neither pilot maintained sufficient airspace observation during their respective left turns, so each failed to detect the other glider in time to avoid conflict.
- Late sighting head-on: HB-219’s pilot suddenly saw HB-559 immediately ahead on a nearly frontal collision course at about 2500 m, leaving no time or space for effective evasive action.
- Mid-air structural damage: The gliders collided nearly head-on, breaking off the left wing tip section of HB-559 and heavily damaging the wing root and canopy area of HB-219.
- Crash - fatal: HB-559 entered an unrecoverable inverted spin and crashed on the west slope of Muottas Muragl killing both occupants, while the damaged HB-219 was recovered to a safe landing near Samedan by its uninjured pilot.