HpH 304

The HpH 304 is a single‑seat, high‑performance motor glider produced by the German sailplane manufacturer Glasflügel in the early 1970s. Developed as a successor to the successful Glasflügel H-301 Libelle, the 304 incorporated a lightweight composite airframe, a retractable 18‑kW two‑stroke engine and a sophisticated wing design with built‑in water ballast. First flown in 1971, the prototype demonstrated a glide ratio of 38 : 1 and a maximum speed of 250 km/h, proving that a powered sailplane could match the soaring capabilities of pure gliders while offering self‑launch capability. Production continued until 1976, with roughly 150 examples completed, many of which were exported to clubs in the United States, Switzerland and the United Kingdom. Key features include a T‑tail, carbon‑reinforced fiberglass construction, automatically deploying propeller and a cockpit equipped with a modern Kollsman altimeter and variometer. The HpH 304’s blend of high‑efficiency aerodynamics, reliable self‑launch, and ease of handling made it a benchmark in the evolution of motor gliders, influencing later designs such as the Ventus and the Schempp‑Hirth Mini‑N. Its legacy endures in contemporary sailplane training and competition circles. Today, restored examples still appear at airshows, inspiring new generations.