1½ Strutter

The Sopwith 1½ Strutter was a British two‑seat biplane fighter‑reconnaissance aircraft introduced in 1916 by the Sopwith Aviation Company. Designed by Herbert Smith, it was the first Sopwith type to employ a synchronized Vickers machine gun firing through the propeller arc, giving pilots a decisive advantage in dogfights. Powered usually by a 130‑hp Clerget rotary engine, the Strutter featured a sturdy spruce‑and‑plywood fuselage, equal‑span wings with slight stagger, and a distinctive “1½‑strut” interplane bracing that gave the aircraft its name. Its versatile layout allowed rapid conversion between single‑seat fighter, two‑seat reconnaissance, and light‑bombing roles; many were fitted with external racks for 25‑lb bombs. First deployed with No. 18 Squadron on the Western Front, the type saw extensive service with the Royal Flying Corps, the Royal Naval Air Service, and several Allied air forces, including the United States Army Air Service. Though quickly outclassed by newer designs such as the SE5a, the 1½ Strutter demonstrated the practicality of synchronized armament and multi‑role capability, influencing later WWI fighters and establishing Sopwith as a leading wartime aircraft manufacturer. Its robust construction also made it a popular trainer for post‑war civilian pilots, extending its legacy into the early 1920s.

Sopwith Aviation Company

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Design & Classification