What happened
A Piper PA-25 tow plane was used to tow a Blanik L-23 glider to approximately 1,200 feet AGL west of the airport. Following the release of the glider, the tow pilot returned to the airstrip and entered a right traffic pattern from the east to land on the powered runway (runway 3<0xA0>6).
Simultaneously, the glider pilot, having failed to find expected lift, entered a left downwind for landing on the parallel sailplane runway (runway 3<0xC2><0xA0>6). Due to another sailplane being positioned ahead of the Blanik, the pilot extended the downwind turn to the base leg. During this maneuver, the glider was lower than normal and further from the runway.
As the tow plane reached its base leg for the powered runway, the glider pilot elected to land on the powered runway, which is available for gliders in emergency situations, because the glider was low and a preceding aircraft had just landed. The pilot of the PA-25 reported that the Blanik was not visible in front of or underneath the tow plane. As the Blanik touched down, the PA-25 landed on top of the glider, straddling it until both aircraft came to a stop. Both aircraft were owned and operated by the same soaring association, and neither aircraft was equipped with a radio.