What happened
During a downwind approach, the certified flight instructor (CFI) operating the glider observed that the aircraft was too low for a normal approach and landing. To compensate, the CFI maneuvered to cut the corner of the approach, flying over a small clump of trees. On the downwind side of these trees, the aircraft encountered significant sink. The glider subsequently landed in a soft field, where it bounced hard and the right wingtip dug into the ground. The student pilot on board reported a sequence of events similar to that described by the CFI.
The investigation
The instructor reported no mechanical malfunctions regarding the aircraft during the flight.