LS 3-Absturz bei St-Imier unter turbulenten Bedingungen führt zu Todesfall
Am 14. Juni 1992 stürzte eine Rolladen-Schneider LS 3 während eines lokalen Trainingsflugs in der Nähe von St-Imier, Schweiz, ab. Das Segelflugzeug, das von seinem Besitzer gesteuert wurde, verlor Berichten zufolge in turbulenten Bedingungen die Kontrolle und wurde später in einem bewaldeten Gebiet zerstört aufgefunden. Der Pilot überlebte den Aufprall nicht. Die Untersuchung konnte die genauen Gründe für den Kontrollverlust nicht feststellen, wies jedoch auf herausfordernde Windverhältnisse zum Zeitpunkt des Unfalls hin.
- Local soaring flight: After an aerotow launch from Courtelary and release near Tramelan, the pilot continued a local soaring flight in turbulent bise conditions in the St-Imier valley area.
- Turbulent bise winds: A bise wind regime over the Jura created locally turbulent and gusty conditions with abrupt changes in wind intensity near the terrain.
- Aft CG limit: The glider’s mass was within limits but the center of gravity was at the aft limit, making the aircraft more sensitive in pitch and potentially in stall and spin behavior.
- Low-altitude turn in sink: While apparently unable to find sufficient lift and flying low in the St-Imier valley, the pilot initiated a right turn, likely to interrupt the flight or reposition, at a height where margins were limited.
- Uncontrolled spiral: A witness saw the glider suddenly roll around its longitudinal axis until the full wingspan was visible and then enter a tight, descending turn, consistent with an inadvertent spiral or spin entry.
- Rudder input applied: Autopsy evidence of a hard left rudder pedal input indicates the pilot attempted to counter the rotation, but had insufficient height to complete a recovery.
- Crash - fatal: Still in a rotating descent, the glider struck treetops, inverted, and impacted the bottom of a wooded ravine, destroying the aircraft and fatally injuring the pilot.