Grunau Baby II se estrella contra árboles cerca de Zweisimmen tras vuelo prolongado

El 8 de agosto de 1962, un Grunau Baby II pilotado por un estudiante se estrelló contra una ladera boscosa cerca de Zweisimmen, Suiza, después de un vuelo de casi cuatro horas. El incidente ocurrió cuando el piloto intentó ganar altitud en condiciones de sustentación decreciente. El planeador sufrió daños significativos, pero el piloto resultó ileso. Las investigaciones revelaron un defecto en el sistema de control del timón, aunque no se consideró la causa principal del accidente. El accidente probablemente se debió a una entrada en pérdida del avión en proximidad al terreno.

1. Aerotow ridge flight: The student pilot aerotowed from Zweisimmen at 14:20 for a solo ridge/wave soaring flight in the Grunau Baby II, later climbing in wave lift to about 3300 m.
2. Very low experience: The pilot had only about eight hours total glider time, with limited solo duration experience prior to this flight.
3. Excessive flight duration: Contrary to training guidelines limiting early soaring flights, the student remained airborne for nearly four hours, leading to probable fatigue.
4. Diminishing evening lift: Towards evening the wave lift weakened, and around 18:00 the pilot was down to about 800 m above the valley floor near St. Stephan with the valley already in shadow.
5. Low, close-in ridge soaring: Instead of committing to landing, the pilot attempted to gain more height in weak, localized lift by flying repeatedly close along the steep, forested west slope of the Girshubel.
6. Stall near terrain: In the weakening upslope lift while maneuvering close to the hillside, the glider was probably flown into an over‑stalled condition with reduced control effectiveness at low height.
7. Crash - no injury: At about 18:12, after roughly 3 hours 50 minutes of flight, the glider flew into trees on the Girshubel slope, heavily damaging the wings while the pilot remained uninjured.