DG-600 elevator jams nose-down on winch launch after a rigging error

A DG-600 was substantially damaged when its elevator jammed nose-down on a winch launch. The day before, the experienced owner had reassembled the glider and connected the horizontal tail alone; the elevator drive was not fully engaged, leaving only partial travel. On the pre-flight the elevator felt abnormally stiff, but he put it down to the nose-down trim. Just after liftoff the elevator went nose-down on its own; he pulled back hard, with no effect, and the glider hit the runway, released the cable and ground-looped into a field. Investigators linked the undetected mis-assembly to poorly-guided visual and control checks after rigging.

1. Solo tail reassembly: The day before, the experienced owner reassembled the glider and connected the horizontal tail alone; this was the first flight since.
2. Elevator drive not engaged: The elevator control roller was not seated in its guide, leaving the elevator only slight, not full, travel.
3. Stiffness noticed but dismissed: On the pre-flight the elevator felt abnormally stiff, but he put it down to the nose-down trim setting; the visual and control checks did not catch the fault.
4. Elevator goes nose-down on launch: Just after the winch liftoff the elevator moved nose-down on its own; he pulled back hard against heavy resistance with no effect.
5. Struck the runway, ground loop: The glider hit the runway, the cable released on impact, and it ground-looped into a field beside the strip; it was substantially damaged and the pilot was unhurt.