Of course, one very useful aspect of the rudder that, so far, has not been discussed is keeping the aircraft straight when one of the engines fails (assuming you're not flying an Airbus or 777
). If, for instance, your right engine fails, then you find yourself in a position with the same thrust coming from the left side of the aircraft and distinctly less from the right, causing the aircraft to yaw to the right. This will then require left rudder to yaw the nose back to the left and keep you on your merry and straight way. The good thing is, just like elevators on light aircraft, airliners have trim for all of the flight controls (ailerons, elevators/horizontal stabiliser, rudder), so you don't have to sit there all day with a bootful of rudder in to keep the thing straight. Once you're level and the thrust of the live engine(s) on the opposite side to the 'dead' engine reduces, then so does the need for as much rudder input and, therefore, rudder trim. Finally, the further from the fuselage the engines, the more of a yawing moment in produced. For example, a 717 with it's engines mounted on the body of the aircraft will produce far less yaw than a 767 with the engines out on the wings, just as the failure of an inboard engine on a 747 will have less effect than if an outboard engine gives up the will to live.
Apart from that, jet pilots are very lazy because they don't use the rudder pedals, apart from a bit of steering during takeoff and landing and somewhere to rest your feet during the hours of cruise.....until it's time to go into the bunk.
