Incident d'Elfe S4 lors de l'atterrissage à Wenslingen entraîne la destruction de l'appareil et des blessures au pilote
Le 6 août 1973, un planeur Neukom Elfe S4 a connu un incident d'atterrissage près de Wenslingen, en Suisse. Le pilote, participant à un cours de formation, a rencontré des turbulences et des courants descendants, conduisant à une tentative d'atterrissage en campagne sur un champ. Lors de l'approche d'atterrissage, le planeur a décroché et s'est écrasé, entraînant la destruction de l'appareil et des blessures pour le pilote. Le rapport officiel a identifié l'utilisation d'une approche d'atterrissage inappropriée et le non-maintien de la vitesse minimale de vol comme causes probables.
- Cross-country landing: During a cross-country training flight after aerotow departure from Courtelary, the pilot prepared for an off-field landing near Wenslingen due to loss of lift.
- Downdrafts and turbulence: In the area around Zeglingen the pilot encountered downdrafts and turbulence, forcing him to descend toward the Wenslingen plateau.
- Obstructed landing approach: The selected field was suitable in size and surface but had a 10 m high power line crossing the approach path about 90 m before the landing area.
- Spiral over landing field: Instead of flying a standard landing circuit, the pilot chose to circle down in a sink spiral over the landing field from about 100 m AGL with the power line cutting across his flight path.
- Low tight base-to-final: After 3–4 full circles, the pilot extended the landing gear at low height and initiated a very tight 180° turn in front of the power line masts to align with the landing direction.
- Stall in steep turn: While banked and slipping left in this low-altitude turn, the glider was flown below minimum speed and stalled about 10 m above ground, departing over the left wing.
- Crash - minor injury: The glider crashed into a clover field approximately 77 m short of the intended landing area and 13 m abeam the power line, destroying the aircraft and injuring the pilot.