There are two versions of the famous WWI fighter plane
, the Spad VII and the Spad XIII.
The Spad VII was a French-made single-gun biplane that first flew in July 1916 it is famous as the plane used by the volunteer American pilots in the Escadrille Lafayette, which eventually became the 103rd Aero Squadron.
The Spad XIII had two Vickers 303 machine guns to counter the newer twin-gun German designs, and was fielded in August of 1917. It was the plane most identified with Eddie Rickenbacker's Hat-in-the-Ring Squadron.
There was a lesser-known earlier version that was a two-seater, a "pusher" design (The prop was at the back of the plane) with the gunner's nacelle in front of the pilot so he could fire unobstructed. It was heavier and slower than a single-seat fighter, for obvious reasons, and so wasn't very successful.