Schleicher ASK 21

The Schleicher ASK 21 is a two-seat glider produced by Alexander Schleicher GmbH &amp; Co.
The glider is made out of glass-reinforced plastic. It's designed for beginners.
But it's also used for aerobatics and cross-country flying. 
Design.
The ASK 21 is designed by Rudolf Kaiser. He made it to replace the old ASK 13. It's still in production to this day.
Something interesting is the T-shape tail that the glider has. Around a 1000 units where build. 
It is the first glass-reinforced plastic glider made by Schleicher. It first flew in February of 1979.
In 2018 a new glider got introduced, the Schleicher ASK 21B.
Variants.
ASK 21B.
Improved version of the original ASK 21. New features: automatic control connections, internal spin ballast, revised canopy, more effective ailerons.
Specifications (ASK 21).
General characteristics
Performance