Collision de Ka 4 Rhönlerche II avec un câble de remorquage lors de l'atterrissage à Zürich-Brunau
Le 25 août 1989, un Ka 4 Rhönlerche II a été impliqué dans une collision lors d'un spectacle aérien à Zürich-Brunau. Le planeur, transportant un pilote et un passager, a heurté un câble de remorquage d'un autre planeur lors de son approche d'atterrissage. La collision a entraîné la rupture de l'aile droite, provoquant une descente incontrôlée d'environ 30 mètres. Le pilote a subi des blessures mortelles, tandis que le passager a été grièvement blessé. L'enquête officielle a attribué l'accident au non-respect par le pilote du circuit d'atterrissage prescrit.
- Winch launch flights: During an airshow at Allmend Brunau, the Rhönlerche II HB-571 conducted a winch launch as the first of two closely spaced passenger flights using a double-drum winch.
- Second cable still airborne: After HB-571 released its first-launch cable and while it was still in the circuit, the second glider was launched on the remaining winch cable, which was still being reeled in and not yet fully on the ground.
- Abbreviated landing circuit: Before the second winch cable was fully retrieved, the pilot of HB-571 initiated an abbreviated landing circuit that took the glider across the winch area instead of following the prescribed pattern.
- Right wing hits cable: While flying crosswise in front of the winch, the right wing of HB-571 struck the still-descending second winch cable beneath its parachute, which sawed through the outer wing section at about 35 m height.
- Loss of control and fall: The collision with the cable caused an immediate loss of control, and the glider entered an uncontrolled right-rolling descent from approximately 30 m, impacting nearly nose-first.
- Crash - fatal: The glider was destroyed in the vertical impact, the pilot was fatally injured, and the passenger sustained serious injuries.