Incidente del K 8 B cerca de Geissflue, Suiza: entrada en barrena lleva a accidente en área boscosa
El 23 de julio de 1970, un Alexander Schleicher K 8 B experimentó una entrada en barrena y se estrelló en un área boscosa cerca de Geissflue, Suiza. El incidente ocurrió durante un vuelo cuando el planeador entró en barrena a baja altitud, resultando en una colisión con los árboles. El piloto sufrió heridas graves y el planeador fue destruido. La investigación oficial confirmó que la barrena fue iniciada debido a una entrada abrupta del timón a baja velocidad y altitud.
- Ridge soaring flight: After aerotow departure from Grenchen, the pilot was ridge and thermal soaring along the Jura between Hasenmatt and Geissflue at relatively low height above terrain.
- Aft CG within limits: The glider’s center of gravity on this flight was at 394 mm behind the reference point, in the rear part of the allowable range, making it easier to enter a spin.
- Low speed near ridge: While flying slightly north of the ridge crest, the glider was being flown at relatively low airspeed and low height above the trees, reducing stall and spin margins.
- Abrupt left turn: West of Geissflue, over the crest, the pilot initiated a relatively abrupt left turn at low speed.
- Unintended left spin: The combination of low speed, brusque rudder input, and aft CG caused the K 8 B to enter a left spin with rapid height loss.
- Insufficient spin recovery: The pilot either did not immediately apply or could not complete effective spin recovery, and due to the very limited altitude was unable to stop the spin before ground impact.
- Crash - serious injury: Still in a left-turning, nose-low attitude, the glider descended about 65 m and crashed into the forested north slope below the ridge crest, seriously injuring the pilot and destroying the aircraft.