Aterrizaje en campo del ASW-15 en terreno desafiante cerca de Rüschegg-Graben, Suiza
El 7 de mayo de 1972, un Schempp-Hirth ASW-15 realizó un aterrizaje en campo cerca de Rüschegg-Graben, Suiza. El piloto, que participaba en una competencia regional, encontró dificultades para regresar a Berna debido a la desorientación y a una falla reportada del variómetro. El piloto optó por aterrizar en un pequeño campo rodeado de obstáculos, lo que resultó en un aterrizaje brusco que dañó el fuselaje y la cola de la aeronave. A pesar de los graves daños al ASW-15, el piloto salió ileso y no hubo daños a terceros.
- Cross-country return leg: During the return leg of a Bern–Romont–Bern task, the pilot was flying cross-country in weak thermals under 4–6/8 cumulus with bases around 1400–1700 m.
- Disoriented near Bern: On the way back the pilot had difficulty locating the Bern airfield and drifted south of the intended course toward the Schwarzenburg area.
- Weak thermals, low height: In the Schwarzenburg area the pilot was at relatively low altitude in generally weak thermal conditions, limiting his options.
- Perceived vario failure: Near the shortwave transmitter at Schwarzenburg the pilot reported a temporary failure of the electric variometer, which he believed hindered his ability to exploit the weak lift, although a mechanical variometer remained available.
- Chooses small field: Recognizing his low height, the pilot decided to outland in a small 160 m field that was preceded by trees and a telephone line and bordered by an orchard and a solid fence.
- Long landing and ground loop: Despite using a sideslip and full airbrakes, the glider touched down only about 120 m into the field, and to avoid colliding with the fence the pilot forced the left wing onto the ground and executed a ground loop, bending the fuselage and damaging the tail.
- Outlanding - damage: The glider sustained severe structural damage in the off-field landing and ground loop, while the pilot remained uninjured and no third-party damage occurred.