For this addon, allow me a small lecture of historical background for it. During the beginning of the First World War, military aviation was just becoming a reality, and the first aerial battles took place primarily with primitive fighters attacking equally primitive observation aircraft. The need to protect the observation aircraft led to greater use of fighters by both sides, as well as the development of fighters to shoot down the observation aircraft. The worst began when a brilliant Dutchman, Anthony Fokker, developed the "interrupter gear" which allowed a machine gun to fire through the propeller arc and not strike the blades. (There is a controversy about whether or not he did indeed develop the interrupter gear, but he is generally credited with it anyways because it was used on one of his own aircraft) The machine gun was mounted on the Fokker Eindecker, a primitive monoplane fighter, and this little aircraft created what was to be called the "Fokker Scourge." For months, the Eindeckers swept their opponents from the sky using their top-secret interrupting gear. The Allies answered with aircraft like the DH2, which mounted a forward-firing machine gun but employing a pusher-type engine arrangement. On conventional aircraft, machine guns were mounted atop the upper wing, above the proppeller arc. They were rudimentary arrangements, but they sufficed until the Allies could copy Fokker's sinister invention and mount it on their own aircraft.