Kollision zwischen Bell 47 G3 Hubschrauber und B-4 Segelflugzeug nahe Sanetschpass führt zu drei Todesopfern

Am 15. Juli 1978 kam es um 12:25 Uhr zu einer frontalen Kollision zwischen einem Hubschrauber und einem Segelflugzeug etwa 3 km nord-nordwestlich des Sanetschpasses. Der Hubschrauber HB-XFA startete um 11:55 Uhr von Gruyères, während das Segelflugzeug HB-1259 um 10:50 Uhr von Saanen abhob. Beide Piloten und die Passagierin des Hubschraubers wurden tödlich verletzt, und die Flugzeuge wurden vollständig zerstört. Die Untersuchung ergab, dass die Piloten das jeweils andere Luftfahrzeug nicht rechtzeitig wahrnahmen, was zu dem Unfall führte. Es wird empfohlen, die Sichtbarkeit und das Situationsbewusstsein der Piloten in solchen Lufträumen zu verbessern.

1. Aerotow to cruise: The glider HB-1259 was aerotowed from Saanen at 10:50 and released after about five minutes near the south slope of Eggli to begin an alpine soaring flight.
2. High-traffic glider zone: The flight took place within an active alpine glider zone near Sanetschpass, designated as a danger area with concentrated soaring activity.
3. Poor mutual visibility: Flight tests later showed that a B-4 glider is very hard to see from a Bell 47 and that the helicopter is not audible from the glider, making see-and-avoid difficult.
4. Converging flight paths: Around 12:25 the glider, circling north-northwest of Sanetschpass, and the helicopter flying toward Valais approached each other on nearly opposite headings at similar altitude without visual acquisition.
5. No effective avoidance: Neither pilot initiated an avoidance maneuver, indicating that the opposing aircraft was not seen in time to react.
6. Rotor strikes glider: The helicopter’s main rotor disc intersected the glider’s fuselage at about a 55° bank angle, cutting the B-4 longitudinally through the cockpit and right wing root and fatally striking the glider pilot.
7. Crash - fatal: Both the disintegrated glider and the damaged helicopter fell onto the snow-covered scree slope at Lapi di Bou NNW of Sanetschpass, destroying both aircraft and killing all three occupants.