The Nieuport 17 reached the front line in March 1916, and was used by many British squadrons as well as the Aéronautique Militaire. Powered by a 110 hp (later 130 hp) Le Rhône radial engine, it had outstanding maneuverability, and an excellent rate of climb. It was generally armed with a synchronized Vickers mg or an above-wing Lewis machinegun, although rarely with both. The Lafayette Escadrille, American volunteers in French service, used the “Sioux” markings on its Nieuports after April 1917.