"...the glider proved popular with pilots and clubs thanks to its simple design, pleasant handling characteristics and sufficent performance for serious cross country flights. The basic design was refined into the most numerous variant, the Ka6-CR's. In 1963 Otto Schäuble and Karl Betzler flying two Ka6-CR's broke the world distance record flying from Stuttgart, Germany to Saint Nazare on the French Atlantic coast a total of 876km."(The Schleicher Ka6 Site)
"...and competition from the new plastic composite sailplanes which had appeared on the market by now. Consequently, its production reached far into the Schleicher plastic composite era.
It was as late as 1972 that production finally ended mainly due to construction costs, in favour of the ASW 15."(Alexander Schleicher Segelflugzeugbau)