Atterrissage en campagne d'un Standard Libelle près de Schwarzenburg entraîne des dommages importants
Le 7 mai 1972, un planeur Glasflügel Standard Libelle a effectué un atterrissage en campagne près de Schwarzenburg, Suisse. Le pilote, participant à une compétition régionale, a rencontré des descentes d'air inattendues lors du vol retour de Berne à Romont. Contraint de se poser dans une zone vallonnée, le planeur a atterri sur un champ herbeux, a dépassé un chemin de champ et a percuté un talus, entraînant des dommages importants au fuselage. Malgré les dommages sévères à l'appareil, le pilote est resté indemne. L'enquête a conclu que l'accident était dû à un atterrissage en campagne dans un terrain inapproprié.
- Cross-country return leg: During the return leg of a Bern–Romont–Bern cross-country task, the pilot was flying the Standard Libelle back toward Bern in hilly terrain.
- Encounter strong sink: About 10 km from the destination, the glider encountered unexpectedly strong downdrafts that prevented continued glide to Bern.
- Unsuitable landing terrain: The surrounding hilly area offered few suitable landing options, and a field path forming a 60 cm deep ditch across the chosen field was hardly visible from the air.
- Forced outlanding attempt: The pilot elected to perform an outlanding on an uphill grassy field and chose to land with the landing gear retracted to shorten the landing roll.
- Impact with field edge: After touchdown the glider overflew the sunken field path and then struck the slightly raised opposite edge, breaking the fuselage behind the wing trailing edge and rendering the aircraft uncontrollable.
- Uncontrolled jump and second impact: The now uncontrollable glider made an approximately 15 m jump and then impacted nose-first in a beet field before sliding to a stop in normal attitude.
- Outlanding - damage: The pilot was uninjured but the glider sustained severe structural damage in the off-field landing.