When the First World War broke out, W.O. put his ambition to start a car company on hold and instead used his secret advantage to help his country. As a captain in the Royal Naval Air Service, he used his aluminium pistons to create an engine for fighter aircraft that was significantly more powerful and reliable than previous versions, which had been prone to overheating and seizing up in combat. The first Bentley Rotary engine, the BR.1, made the Sopwith Camel the most successful British fighter aircraft of the war. W.O. went on to develop the BR.2, and visited active squadrons while supervising its production. At one aerodrome, as he later recalled, “every gun in Flanders seemed to open up on us” during a strafing attack by Manfred von Richtofen, otherwise known as the Red Baron. Thankfully for the future of motoring, W.O. and the officer accompanying him survived by jumping into a canal.