Piper PA-18-150 Absturz nahe Vilan nach Schleppseilbruch mit Pilatus B4-PC 11AF

Am 5. August 1977 startete eine Piper PA-18-150, die einen Pilatus B4-PC 11AF schleppte, vom Flugplatz Bad Ragaz. Während des Fluges in der Nähe von Vilan lockerte sich das Schleppseil und riss dann, was dazu führte, dass die Piper die Kontrolle verlor und in einen steilen Hang stürzte. Der Pilot der Piper kam bei dem Absturz ums Leben, und das Flugzeug wurde zerstört. Der Segelflugzeugpilot konnte sicher zum Flugplatz zurückkehren. Der Vorfall ereignete sich in der Schweiz, ohne dass Drittschäden gemeldet wurden.

1. Aerotow ridge climb: During an aerotow from Bad Ragaz toward the Vilan area, the tow combination climbed along the ridge after passing the Sadreinegg ridge in rising air.
2. Tight turn near slope: After crossing the Sadreinegg ridge, the towplane initiated a relatively sharp right turn toward the mountainside and then abruptly reversed into a sharp left turn in close proximity to the slope.
3. Low height and clearance: The tow was being flown with low height above ground and small horizontal distance from the slope, below prescribed minima, leaving little margin to recover from upset.
4. Slack tow rope: During the right turn the glider climbed slightly above the towplane, causing the tow rope to slacken and hang through.
5. Glider fails to release: When the towplane disappeared from his field of view in the steep left turn and turbulence, the glider pilot took the release handle in hand but did not immediately jettison the tow.
6. Rope snatch and break: As the towplane reversed into the sharp left turn in turbulence, the slack rope suddenly came taut, abruptly lifting the towplane’s tail toward the slope and then failing at the glider-side splice instead of at the weaker intended weak link.
7. Crash - fatal: At very low height the towplane, upset by the rope snatch and close to the steep terrain, entered a near-vertical descent and impacted the slope fatally injuring the tow pilot, while the glider released and later landed safely back at Bad Ragaz.