SZD-30 Pirat tree strike on low base-to-final in strong gust

The pilot of an SZD-30 Pirat was seriously injured when the glider struck trees on a low base-to-final turn at Ballenstedt in strong southwesterly turbulence; glider destroyed. After a winch launch from RWY 27 to ~400 m for a planned lee-wave flight and no usable lift north of the field, the pilot entered the southern circuit and arrived base-to-final at only ~90 m AGL. In the turn to RWY 27 the wing contacted treetops at the southern field edge; the glider yawed and struck adjacent fallow ground. The Pirat was slightly above max mass. No technical faults found.

1. Winch launch RWY 27 for lee-wave flight: The pilot took a winch launch from RWY 27 at Ballenstedt and released at about 400 m AGL for a planned lee-wave flight.
2. Strong SW wind + turbulence at field: At the time of the flight there was a strong southwesterly wind with significant turbulence reported at the airfield.
3. Slightly above max mass: The Pirat was slightly above its maximum permitted takeoff mass, reducing the energy margin in turbulent low-altitude flight.
4. Arrives base-to-final at only ~90 m AGL: After searching for lift north of the airfield without success, the pilot entered the southern circuit; he arrived at the base-to-final position at only about 90 m AGL and initiated the turn to RWY 27 from there.
5. Treetop contact in turn to RWY 27: During the low base-to-final turn the wing struck the tops of trees at the southern edge of the airfield, yawing the glider out of the turn.
6. Yaw + impact on fallow ground; pilot SI: Following the tree strike the glider yawed and impacted adjacent fallow ground near the airfield. The pilot was seriously injured; the airframe was destroyed. No technical faults were found.