The Immelmann manoeuvre was first used in World War I aerial combat by German flying ace, Max Immelmann. This tactic was initially performed using Fokker Eindekkers, monoplane fighter aircraft. After attacking an aircraft, the attacker quickly reclimbed past the enemy aircraft and, on the verge of a stall, applied full rudder control to turn his aircraft around. The pilot then righted his aircraft at the top of the loop, facing down on the enemy aircraft, putting himself in a fresh attack position. The Immelmann was a tricky manoeuvre to perform, requiring the pilot to reposition himself at very low speeds. While it allowed the pilot to dive from above, approaching from any direction, it also made the plane vulnerable to attack. The slow hovering speed when performing the manoeuvre made the aircraft an easy target, causing its use to be discontinued.