The Airco DH.5 was a British First World War single-seat fighter aircraft designed specifically to replace the obsolete Airco DH.2. It was one of the first British fighter designs to include the improved Constantinesco interrupter gear, which allowed a forward-firing machine gun to fire through the propeller faster and more reliably than the older mechanical gears. It was also one of the earliest biplanes to feature a marked "back-stagger" of its wings.