Ka 6 BR trifft auf plötzliche Wetteränderungen während des Anflugs auf den Flugplatz Montricher

Am 19. Mai 1973 war ein Segelflugzeug vom Typ Ka 6 BR in einen Vorfall auf dem Flugplatz Montricher in der Schweiz verwickelt. Der Pilot, der seinen ersten Trainingsflug der Saison absolvierte, stieß auf sich schnell verschlechternde Wetterbedingungen aufgrund einer durchziehenden Kaltfront. Trotz Bemühungen, den Anflug anzupassen, zwangen starke Winde und Abwinde das Segelflugzeug zu einer Landung vor der Landebahn, was zu erheblichen Schäden am Flugzeug führte. Der Pilot blieb unverletzt, und es wurden keine Verletzungen gemeldet. Die Untersuchung bestätigte, dass die plötzlichen ungünstigen Wetterbedingungen der Hauptfaktor für den Vorfall waren.

1. Aerotow local soaring: The pilot departed Montricher by aerotow for his first training flight of the season and climbed in 1–3 m/s lift in the Mont-Tendre area.
2. Weather deteriorates rapidly: A fast-moving cold front with strong gusts and rapidly worsening conditions approached, and at 2050 m QNH the pilot was instructed by radio to return due to the deteriorating weather.
3. Strong gusty headwind: On return overhead the field the pilot estimated a strong surface wind of about 43 km/h from the windsock, with actual conditions including stronger gusts and turbulence than he anticipated.
4. High approach, airbrakes used: Turning onto final for runway 21 at about 230 m AGL, the pilot judged himself too high and partially extended the airbrakes, reducing his altitude margin.
5. Insufficient altitude margin: By the time a colleague on the ground advised him to retract the airbrakes, the remaining altitude was no longer sufficient to comfortably reach the runway threshold in the strong wind.
6. Downdrafts on short final: On short final at 110–120 km/h the pilot encountered stronger-than-expected headwind and reported passing through a zone of downdrafts, further degrading his glide path after crossing the nearby railway line.
7. Outlanding - damage: Unable to reach the runway, the glider touched down into a 4–5 m high hedge about 175 m short of the threshold, yawed a quarter turn left, and was badly damaged while the pilot remained uninjured.