The Airco DH.4 was a twin seat day bomber tractor biplane, another of Geoffrey de Havilland’s designs. The type became the first specifically designed bomber capable of defending itself. It was armed with forward firing Vickers .303 machine gun mounted on the nose and twin Lewis machine guns mounted in the observers cockpit. The type could carry up to 322lb of bombs under the fuselage and on wing racks. The type entered service with the RFC in January 1917 and stayed in service until the end of the war. In the spring of 1917, the RNAS also employed the DH.4 for coastal patrol. It was a hugely popular aircraft, easy to fly and very reliable. Powered by the Rolls Royce Eagle engine it was able to gain higher altitude and speed than the German fighters at the time.

Most of the DH.4’s were built in America by Daytona-Wright and shipped over for the American forces in 1918. It was the only combat aircraft to be built by the Americans during WW1.

After the war many DH.4’s continued to be in service with a large number being converted for civilian scheduled flights throughout Europe.