Mucha 100 A stürzt nach Strömungsabriss bei Siblinger Randen in Wald, Pilot verletzt

Am 31. Juli 1966 stürzte ein Mucha 100 A Segelflugzeug in einen Wald nahe Siblinger Randen, Schweiz. Der Pilot führte eine Kurve in geringer Höhe aus, als das Flugzeug bei mäßiger Turbulenz in einen Strömungsabriss geriet, wodurch der linke Flügel Bäume streifte. Das Segelflugzeug erlitt erhebliche Schäden, aber der Pilot zog sich nur leichte Verletzungen zu. Der Vorfall wurde auf unangemessene Flugtaktiken und die Missachtung von Höhenvorschriften zurückgeführt.

1. Aerotow ridge flight: The pilot aerotowed from Schaffhausen and released at about 200 m above the airfield, then proceeded to fly along the west slope of the Siblinger Schlossranden in weak ridge lift.
2. Low, weakening lift: As the pilot continued north along the Churztal, the initial 1 m/s climb decreased to zero and then to 0.5–1 m/s sink, with his height above ground reducing due to sink and rising terrain.
3. Very low ridge height: By the time he reached the northern part of the Churztal, his height above ground had dropped below the recommended 50 m minimum for ridge flying, leaving little margin to recover from disturbances.
4. Low-altitude turn in lee: In moderate turbulence and lee sink in the northern Churztal, the pilot initiated a left 30° bank reversal turn at low altitude to head back south along the ridge.
5. Speed decay and sink: Shortly after starting the turn, the airspeed suddenly decreased and the glider began to mush and sink, likely due to turbulence and/or unintentional back pressure at low speed.
6. Attempted recovery: The pilot pushed the stick forward and left to regain airspeed and move away from the slope, but the very low height above the rising terrain made recovery impossible.
7. Crash - minor injury: The left wingtip struck trees and the glider crashed into the forest below the Steinmürlichopf, destroying the fuselage and slightly injuring the pilot.