III.

World War I

As the threat of war in Europe grew before 1914, potential German use of zeppelins (see Airship) for military purposes led Britain's military authorities to look seriously at military aviation; early in World War I, Paris and London were first bombed by zeppelins, which were subsequently withdrawn from use because of their extreme vulnerability. The first United States military aircraft, built by Wilbur and Orville Wright, was tested and accepted in 1909.

The future of air warfare lay with propeller-driven aircraft, first used by the Italian army during the Italo-Turkish War of 1911-1912 to observe movements of the Turkish forces. Britain founded the Royal Flying Corps (RFC) in 1912. When hostilities broke out in 1914, the Allies and the Germans had about 200 aircraft each on the Western Front. The first planes were primarily scout and reconnaissance types, such as the Vickers FB5, slow and vulnerable to anti-aircraft fire. In 1915 the French flying ace Roland Garros became the first person to shoot down a plane by firing a machine-gun through his propeller. The Dutch aircraft designer Anthony Fokker, working with the Germans, developed the Fokker Eindecker, using an interrupter gear to permit machine-guns permanently mounted on a plane to fire through the propeller without damaging the blades; with this modification, and the development of speedier planes, the era of fighter aircraft was born.

Aerial combat produced the aces whose fame became legendary: Germany's Baron Manfred von Richthofen (known as the Red Baron), Georges Guynemer and Charles Nungesser of France, Britain's Albert Ball, William Bishop of Canada, and Eddie Rickenbacker of the United States.

Earlier in the war, bombs were dropped by hand over the side of the cockpit. Later, heavier aircraft were developed, and bombsights and standardized bomb fittings ensured greater effectiveness in striking military and civilian targets. By the war's end in 1918, 254 tonnes of bombs had been dropped in raids over England, causing 9,000 casualties. Although not to be compared with World War II statistics, these raids were psychologically and strategically important, resulting in the diversion of aircraft from the front for air defence at home. The use of massed air power at the front reached its peak in 1918 in the battles of Château-Thierry, St Mihiel, and the Meuse-Argonne. The effect of raids by the RFC on the German forces in March 1918 helped to stop them breaking through.