Accidente del ASW 20L durante la aproximación en Birrhard tras una pérdida de sustentación a baja velocidad

El 30 de marzo de 1985, un Alexander Schleicher ASW 20L se estrelló durante su aproximación a Birrhard, Suiza. El piloto, en su primer vuelo con la aeronave, inició un giro a baja altitud. Durante el giro, el planeador entró en pérdida de sustentación y en una picada pronunciada, resultando en un accidente fatal. El piloto falleció y la aeronave fue destruida. Se señalaron fuertes turbulencias y una preparación inadecuada para el vuelo como factores contribuyentes.

1. Aerotow to local soaring: The pilot aerotowed from Birrfeld in the ASW 20L for his first flight on this type and flew locally for about 20 minutes before returning to land.
2. Rushed first-flight prep: On the day of the flight the pilot had a hectic schedule retrieving equipment and the glider, received no formal type checkout, and had limited time to become familiar with the ASW 20L cockpit and systems.
3. Strong turbulence present: Weather and eyewitness reports indicated strong turbulence in the Birrfeld circuit area during the approach.
4. Slow turn on final: On final approach, offset about 80 m south of the runway axis at 80–100 m height and 400–500 m before the threshold, the pilot initiated a left turn at a low airspeed.
5. Stall and spin entry: About halfway through the turn the radius tightened, the nose dropped steeply, and the glider entered a steep, tight descending spin-like rotation.
6. No effective recovery: The glider continued through roughly 1¼ further steep, tight turns with landing flaps still largely extended, indicating that any recovery attempt did not stop the rotation before ground impact.
7. Crash - fatal: The ASW 20L impacted the ground in a steep nose-down attitude about 350 m before the runway 26 threshold near the N1 motorway, fatally injuring the pilot and destroying the glider.