he newly invented airplane entered World War I as an observer of enemy activity (see The Beginning of Air Warfare, 1914). The importance of the information gathered by this new technological innovation was made evident to all the belligerents in the opening days of the conflict. The equal importance of preventing the enemy from accomplishing this mission was also apparent.
The French were the first to develop an effective solution. On April 1, 1915 French pilot Roland Garros took to the air in an airplane armed with a machine gun that fired through its propeller. This feat was accomplished by protecting the lower section of the propeller blades with steel armor plates that deflected any bullets that might strike the spinning blades. It was a crude solution but it worked, on his first flight Garros downed a German observation plane. Within two weeks Garros added four more planes to his list of kills. Garros became a national hero and his total of five enemy kills became the benchmark for an air 'Ace.'