Pérdida de control durante vuelo de ladera lleva a accidente forestal en Wasserngrat para SZD-8ter de Saanen

El 11 de julio de 1970, el planeador HB-629 sufrió un accidente durante un vuelo, cayendo en un bosque de abetos. El piloto resultó gravemente herido y la aeronave fue destruida. El incidente ocurrió cerca de Wasserngrat en Gstaad, durante un campamento de vuelo a vela. La investigación determinó que el accidente fue causado por un giro a baja altura, resultado de una pérdida de velocidad cuya causa no pudo ser identificada con certeza. Se recomienda mejorar la capacitación de los pilotos en el manejo de situaciones similares.

1. Slope soaring flight: After aerotow from Saanen and release near Hornberg, the pilot flew slope along the Wasserngrat ridge near the restaurant at roughly 100–200 m above terrain.
2. Low height near slope: While flying a wide turn near the ridge and restaurant, the glider was at low altitude over steep, forested terrain, leaving limited height for recovery.
3. Turbulent ridge conditions: The area was affected by irregular turbulence and possible rotor or transition effects from a 10–15 kt northwesterly wind over the ridge.
4. Sudden loss of airspeed: During a left turn back toward the slope at about 85 km/h, the glider likely experienced a brief loss of relative airspeed, leading to an uncommanded stall.
5. Uncommanded spin: The tail suddenly rose and the glider entered a left spin at low altitude, contrary to the pilot’s intentions.
6. Insufficient spin recovery: The surprised pilot pushed the stick forward in an attempt to stop the spin, but with only about 200 m of height available there was not enough altitude for the several turns needed for full recovery.
7. Crash - serious injury: Still in a developed descent, the glider struck the tops of tall fir trees and crashed down through the forest, destroying the aircraft and seriously injuring the pilot.