Airplanes were first used extensively in World War I. Airplanes were not used very much in fighting before World War I. It was the first war to use airplanes as weapons. Airplanes were first used for reconnaissance, to take pictures of enemy land and to direct artillery. Generals, military leaders, were using airplanes as an important part of their attack plans at the end of the war. World War I showed that airplanes could be important war weapons.