Twin II Acro wing digs into long grass on winch ground run

On a winch launch at Yverdon-les-Bains, the instructor and student pilot of a Grob G 103 A Twin II Acro were injured — one seriously, one slightly — and the glider was substantially damaged. During a winch training camp, the glider launched from a grass strip whose mown lane was only about 16 m wide, flanked by grass 30-40 cm high whose hazard was underestimated. Early in the ground run, still on the ground, the right wingtip suddenly caught in the tall grass; directional control was lost and the glider slewed to a stop with its fuselage and both canopies broken.

1. Winch training camp: During a winch-launch training camp at Yverdon, a Grob G 103 A Twin II Acro lined up on the grass strip for launch.
2. Narrow lane, tall grass: The mown lane was only about 16 m wide, flanked by grass 30-40 cm high whose hazard was underestimated.
3. Right wing catches grass: Early in the winch ground run, still on the ground, the right wingtip suddenly dug into the tall grass.
4. Directional control lost: The glider slewed and lost directional control on the ground.
5. Fuselage, canopies broken: It came to rest with the fuselage and both canopies broken; instructor and student injured, one seriously.