ASK 21 yaws off line after a wingtip drops on the winch ground roll

An ASK 21 was substantially damaged and one occupant suffered minor injuries when the left wingtip dropped during a winch ground roll; the glider yawed violently, briefly lifted off and impacted nose-down. The pilot — an experienced instructor with a passenger — launched on RWY 12 in light, aligned wind. The glider rotated around its vertical axis, turned ~150° and from about 2 m struck the ground at ~30–45° pitch, coming to rest 130 m from the launch point with structural damage to forward fuselage and empennage and a destroyed canopy. A dislodged elevator-linkage sleeve was found post-impact but ruled out as a cause.

1. Winch launch on RWY 12, 2 POB: An ASK 21 with two persons on board began a winch launch in direction 120° at Fischbek in light, aligned wind.
2. Left wingtip touches ground: During the initial ground roll the glider's left wingtip contacted the ground.
3. Violent yaw, brief liftoff: The glider rotated violently around its vertical axis, briefly became airborne and turned about 150° before descending.
4. Nose-down impact from ~2 m: From a height of about 2 m the glider struck the ground with the forward fuselage at an estimated 30–45° pitch attitude.
5. Elevator linkage sleeve ruled out: Post-impact inspection found a sleeve from the Wedekind safety pin dislodged in the elevator linkage; this was ruled out as a cause.
6. Stopped 130 m from launch — minor injury: The glider came to rest about 130 m from the launch point with structural damage to the forward fuselage and empennage and the canopy destroyed; one occupant sustained minor injuries.