Aerial warfare was still in its infancy in WWI, the airplane having been invented only fourteen years prior to the start of the war. One of the greatest disadvantages to fighter airplanes was the pilot's inexperience. Most pilots were killed during training exercises. If a pilot was lucky enough to survive this, he was often killed by pilots more experienced than himself. Fighter planes had limited armament and limited fuel supplies in WWI, meaning they could only inflict a minor amount of damage over a limited space.
The planes did have many advantages. A good fighter pilot could capture the imagination of his country and be used to promote the war and sell war bonds. Fighter aircrafts helped to promote the concept of air war in general and their effectiveness against the dirigibles, ended the idea that blimps would be the primary air arm in future wars. Fighter planes could also be used as reconnaissance, scouting enemy trenches and noting the effects of artillery barrages. Fighter aircraft could also be used to protect the early bombers of the period, though these bombers had limited payloads and range.