The DG-400, a self launching glider based on the DG-202, was designed by William Dirks and had its maiden flight in 1981. It has a 15 m Span, or with optional wing tips, a span of 17 m to increase lift. The wings of DG-400 are made of CFRP, the fuselage from GRP with CFRP in the engine. The engine, a Rotax 505 with 43 horsepower, with an electric motor for stert-up and engine retract.
290 DG-400's were built by Glaser Dirks aircraft, now DG aircraft. They had good customer response to the engine display and control unit DEI, which allows even the less technically skilled persons a simplest way of a engine control. This control unit has continued to be developed and is still in production.