However, the final result of the development was Fokker's pushrod control mechanism, "Gestängesteuerung", which allowed the aircraft's forward-firing machine gun to fire only when the propeller was out of the line of fire. As incorporated into the famous Fokker "Eindecker", its use directly led to a phase of German air superiority known as the Fokker Scourge. Despite its shock effect on the enemy, the first Fokker interrupters remained unreliable and were prone to failures. Both Oswald Boelcke and Max Immelmann survived failures which resulted in propellers being shot off and even engines pulled out of their mountings due to the engine becoming unbalanced by the loss of the propeller. Immelmann's eventual death in combat has also been attributed to interrupter gear failure as the aircraft was seen to break up in mid-air while engaged against a Royal Flying Corps F.E.2b.