Letov Š-331

The Letov Š‑331 was a single‑engine, low‑wing monoplane built in Czechoslovakia by the Letov Kbely factory during the late 1930s. Designed by engineers František Šlechta and Vlastimil Škarpa, the aircraft was intended to replace older trainers and to serve as a versatile utility plane for clubs, schools and the Czechoslovak Air Force. It featured an all‑metal stressed‑skin construction, a semi‑monocoque fuselage, and a three‑seat cabin under a rearward‑sliding canopy. Power came from a 135 hp Walter Minor inline engine driving a two‑bladed propeller, giving a maximum speed of 210 km/h, a range of 850 km and a service ceiling of 5 600 m. The Š‑331 incorporated split flaps, a retractable tailwheel, and generous control surface deflection, which made it forgiving for novice pilots while still offering respectable aerobatic capability. Only 48 units were completed before production ceased in 1940, but the type proved significant as one of the last indigenous Czech designs before the occupation, influencing post‑war trainer concepts and demonstrating Letov’s expertise in modern monocoque techniques. Its legacy endures in Czech aviation museums as a symbol of pre‑war innovation. Today, a fully restored Š‑331 regularly flies at historic air events, inspiring new generations of aviators.