<P> Use of the term "ace" to describe these pilots began in World War I, when French newspapers described Adolphe Pégoud, as l'As (French for "Ace") after he became the first pilot to down five German aircraft . The British initially used the term "star - turns" (a show business term), while the Germans described their elite fighter pilots as Überkanonen (which roughly translates to "top guns"). </P> <P> The successes of such German ace pilots as Max Immelmann and Oswald Boelcke were much publicised for the benefit of civilian morale, and the Pour le Mérite, Prussia's highest award for gallantry, became part of the uniform of a leading German ace . In the Luftstreitkräfte the Pour le Mérite was nicknamed Der blaue Max / The Blue Max, after Max Immelmann, who was the first fighter pilot to receive this award . Initially, German aviators had to destroy eight Allied aircraft to receive this medal . As the war progressed, the qualifications for Pour le Mérite were raised, but successful German fighter pilots continued to be hailed as national heroes for the remainder of the war . </P> <P> As the German fighter squadrons usually fought well within German lines, it was practicable to establish and maintain very strict guidelines for the official recognition of victory claims by German pilots . Shared victories were either credited to one of the pilots concerned or to the unit as a whole--the destruction of the aircraft had to be physically confirmed by locating its wreckage, or an independent witness to the destruction had to be found . Victories were also counted for aircraft forced down within German lines, as this usually resulted in the death or capture of the enemy aircrew . </P> <P> Allied fighter pilots fought mostly in German - held airspace and were often not in a position to confirm that an apparently destroyed enemy aircraft had in fact crashed, so these victories were frequently claimed as "driven down", "forced to land", or "out of control" (called "probables" in later wars). These victories were usually included in a pilot's totals and in citations for decorations . </P>

Who is the us air force’s all-time leading ace