SEA IV

The SEA IV was a French single‑engine fighter prototype developed in the final months of World War I by the Société d’Études Aéronautiques (SEA), a joint venture of engineers Louis Béchereau, Henry Potez and Marcel Bloch. First flown in March 1918, the aircraft featured a wooden monocoque fuselage, a tapered wing of equal span, and was powered by a 260 hp Hispano‑Suiza 8Bb V‑8 engine that gave it a top speed of roughly 240 km/h. Its armament consisted of two synchronized Vickers machine guns firing through the propeller arc, a standard for contemporary fighters. Although the SEA IV demonstrated excellent handling and climb performance during trials, the Armistice halted mass production and only a handful of prototypes were built. After the war, Potez bought the SEA assets and incorporated lessons from the design into later successful models such as the Potez 25 and the Potez 534. The SEA IV thus represents a pivotal transitional step, showcasing advanced monocoque construction and aerodynamic refinement that influenced French fighter development throughout the 1920s. Its legacy also inspired later twin‑engine bombers, proving that even limited‑run prototypes can leave a lasting imprint on aircraft engineering.