an Entity references as follows:
The Schleicher ASW 15 is a single-seat sailplane designed in 1968 by Gerhard Waibel and manufactured by Alexander Schleicher GmbH & Co. The ASW 15 has shoulder-mounted wings and an all-flying tailplane, with its single tow-release placement a compromise between winching and aerotowing. The later ASW 15B had several improvements, including a tow-release placed on the plane of symmetry, an 11 cm taller rudder, a slightly larger main wheel, and the provision of a 90-litre water ballast system. It was succeeded by the Schleicher ASW 19.