Flight Review and Departure
Prior to departure, the flight instructor advised the pilot receiving his biennial flight review that windy conditions warranted conservative flying. The two departed in a motor glider and soared in strong lift conditions near the airport with the engine off.
Approach and Handling
Upon returning, the instructor elected to land in the power-off configuration. The pilot delayed the turn to base leg. When turning base, the pilot felt uncomfortable with the approach and relinquished control to the instructor. The instructor then turned the motor glider directly toward the airport, where very heavy sinking air was encountered.
Landing and Descent
The instructor prepared to land short of the asphalt runway on grass but could not maintain sufficient lift to clear bordering trees. The motor glider descended through the trees, shearing off a large section of the right wing, and came to rest on its right side, partially inverted.
Post-Impact Observations
The speed brake handle was found fully extended. The right speed brake was extended; the left speed brake was retracted. The landing runway was 24, with winds from 220 degrees at 16 knots, gusting to 23 knots. An examination of the motor glider revealed no mechanical deficiencies.