Designed by Henry Folland, John Kenworthy, and Major Frank Goodden at the Royal Aircraft Factory, Farnborough, the Scout Experimental 5 was conceived around the new Hispano-Suiza 8A V-8 engine. The prototype, A4561, flew on 22 November 1916; Goodden was killed testing a second prototype in January 1917, but modifications cured the structural flaws. The first production machines reached France with No. 56 Squadron on 7 April 1917. The improved S.E.5a, fitted with the 200 hp geared Hispano-Suiza 8B, arrived in June. It was stable, fast, and viceless—qualities that made it a superb gun platform. Unlike the twitchy Camel, the S.E.5a could be dived at high speed without shedding its wings, and its inline engine ran more quietly than the popping rotaries of the era. Armament consisted of a fixed Vickers machine gun firing through the propeller and a Lewis gun on a Foster mounting over the upper wing, allowing a pilot to stalk a target from below and rake its belly. The Wolseley Viper engine, a reliable licence-built derivative, finally solved early production shortages. By the Armistice, 5,205 S.E.5s and S.E.5as had been built, equipping over twenty British squadrons. South African ace Anthony Beauchamp-Proctor scored fifty-four victories in the type—more than any other pilot. Together with the Camel, the S.E.5a won back the skies of the Western Front and proved that, in aerial combat, a steady gun platform is often more valuable than a flashy turn.