Avia S-103

The Avia S‑103 was a Czechoslovak two‑seat low‑wing monoplane built by the Avia factory in the mid‑1930s. Designed as a sport‑training aircraft, it first flew in spring 1935 and entered limited service with Czechoslovak Air Force training units and civilian aero clubs. The S‑103 combined a semi‑monocoque metal fuselage with wooden, fabric‑covered wings, a layout that was advanced for its country at the time. Power came from a Walter Castor II nine‑cylinder radial engine delivering 85 hp, giving the aircraft a top speed of about 200 km h⁻¹, a service ceiling of 5 500 m and a range of 600 km. Its side‑by‑side seating, generous control surface deflection and gentle stall characteristics made it well suited for primary instruction and aerobatic practice. Only a small series – roughly 30 airframes – was produced before the outbreak of World War II halted further development. Despite the limited numbers, the S‑103 demonstrated the viability of modern metal construction in Czechoslovakia and served as a technological stepping‑stone toward later high‑performance types such as the Avia B‑534 fighter, cementing its place in the nation’s interwar aviation heritage. A handful of surviving examples are displayed in Czech aviation museums, reminding enthusiasts of the ingenuity that marked the pre‑war era.