Some propose that such things as engine-braking control are morally wrong because they take aspects of control away from the rider. Let's think about that. As World War II began, fighter pilots found themselves acting as engine-management systems as well as having to fly the airplane. Propeller pitch, throttle opening, engine rpm, supercharger boost, and impeller drive ratio, plus fuel-air mixture were all his responsibility as well. The American innovation of the constant-speed propeller handled two of these extra variables but, in combat, pilots still had too much to do. German engineers then created the kommandogerat, or "control apparatus," a hydro-mechanical computer that integrated all functions into a single power lever; move it this way for more power, the other way for less. This made Fw 190 pilots more effective by allowing them to concentrate exclusively on flying the aircraft.