Colisión del Ka 4 Rhönlerche II con cable cerca de Pilatussüdfuss, Suiza

El 2 de julio de 1967, un Alexander Schleicher Ka 4 Rhönlerche II colisionó con un cable telefónico cerca de Pilatussüdfuss, Suiza, durante un vuelo de entrenamiento. El planeador, pilotado por un estudiante, golpeó el cable de un teleférico y se estrelló, resultando en la destrucción de la aeronave y la muerte del piloto. El incidente ocurrió mientras el planeador volaba cerca de la montaña en una zona con obstáculos. Las condiciones meteorológicas eran generalmente favorables, pero con débiles corrientes ascendentes.

1. Aerotow to ridge: The student pilot launched by aerotow from Kägiswil and was towed to about 900 m above ground over the hindrance-free western part of the Pilatus south slope near Schwändi-Längenmatt.
2. Weak ridge lift: In the Pilatus south-slope area the available updrafts were weak and marginal, encouraging flight close to the terrain to maintain height.
3. Flight into cable zone: After initially soaring in a safer area and following another glider, the student left that area and began ridge-soaring back and forth along the slope beneath Chretzenalp in the vicinity of the Aeschi–Chretzenalp cableway.
4. Low, close ridge run: While performing hang-soaring passes in weak lift at low height and close to the mountainside, the student flew into a zone containing multiple cableway wires.
5. Telephone cable not seen: Although the pilot likely recognized the main support and haul cables, he failed to perceive the thinner, slightly higher telephone cable of the cableway.
6. Collision with cable: The right wing leading edge struck the 6 mm telephone cable of the Aeschi–Chretzenalp cableway, tearing away about 3.2 m of the wing’s nose skin and causing a sudden loss of speed and control.
7. Crash - fatal: Following the cable strike and severe wing damage, the glider rolled toward the slope and dived steeply into the Giessbach couloir, impacting rocks and fatally injuring the pilot while destroying the aircraft.