Colisión con el terreno cerca de La Sagne durante el remolque aéreo de una SZD-30 en mala visibilidad tras salir de Saanen

El 22 de julio de 1976, ocurrió un grave accidente en La Sagne con el planeador SZD-30 'Pirat'. Durante un vuelo de remolque, el piloto perdió el contacto con el avión remolcador y colisionó con árboles antes de caer al suelo. Las condiciones meteorológicas eran desfavorables, con nubes bajas y visibilidad limitada, lo que complicó la situación para el piloto. La investigación reveló que la cuerda de remolque se rompió durante el vuelo, lo que provocó la pérdida de control. Se recomienda realizar una revisión más exhaustiva de las condiciones meteorológicas antes del vuelo y asegurar que el equipo esté en condiciones adecuadas.

1. Aerotow cruise: During an aerotow ferry flight from Saanen toward La Chaux-de-Fonds, the glider was being towed uneventfully along the planned route.
2. Deteriorating weather: Approaching La Sagne, cloud base and visibility were very low and variable, with stratocumulus and precipitation reducing VFR margins.
3. Tow enters cloud: The towplane, unable to maintain safe clearance below the rapidly lowering cloud base while still towing, turned right and entered the cloud layer while the glider, slightly higher, lost visual contact with the tug and towrope.
4. Glider correction attempts: The glider pilot briefly reacquired sight of the rope off-axis, attempted a heading correction, then lost sight of the rope again while still in cloud and focused forward.
5. Oscillations and rope break: Excessive corrective input caused strong yaw oscillations in the glider, leading to high loads and the failure of the already deteriorated towrope approximately in its middle.
6. Loss of control in IMC: After the rope broke, the glider pilot, disoriented in cloud and having the sensation of being at the top of a wingover near the tug, lost control and descended uncontrolled toward the terrain.
7. Crash - no injury: The glider collided with treetops and then the ground near La Sagne, the wings being torn off and the fuselage passing between two trees so that the aircraft was destroyed but the pilot was uninjured.