The ASK 21 is a popular German two-seater glider, first built in 1979. It is primarily used for beginner instruction and aerobatics training, as well as for transitioning pilots from older wooden gliders like the K 8 to modern single-seat composite gliders. Capable of withstanding g-loads of +6.5 and -4G, it has a maximum speed of 280 km/h. Despite not having the best glide ratio, it is appreciated for its well-balanced handling and safety. The ASK 21 is a well-constructed and robust glider with forgiving flight characteristics.