While planes had already been used in the war for scouting, on 1 April the French pilot Roland Garros became the first to shoot down an enemy plane by using a machine gun that shot forward through the propeller blades. This was achieved by crudely reinforcing the blades so bullets which hit them were deflected away.
Morane-Saulnier Type L is the type of plane that was first shot down by frenchman Roland Garros (inset)
Max Immelmann in 1916, First German WW1 flying Ace
Several weeks later Garros was forced to land behind German lines. His plane was captured and sent to Dutch engineer Anthony Fokker, who soon produced a significant improvement, the interrupter gear, in which the machine gun is synchronised with the propeller so it fires in the intervals when the blades of the propeller are out of the line of fire. This advance was quickly ushered into service, in the Fokker E.I (Eindecker, or monoplane, Mark 1), the first single seat fighter aircraft to combine a reasonable maximum speed with an effective armament; Max Immelmann scored the first confirmed kill in an Eindecker on 1 August.
Fokker E I
This started a back-and-forth arms race, as both sides developed improved weapons, engines, airframes and materials, which continued until the end of the war. It also inaugurated the cult of the ace, the most famous being the Red Baron. Contrary to the myth, antiaircraft fire claimed more kills than fighters.
Our Family at War 