Yaw-rudder not used very much in bigger airplanes?
 

Something that has gotten stuck on my mind is why bigger airplanes almost always only rely on ailerons for correcting horizontal position on the approach, is this a misconseption or is there a reason why yaw isn't used as much?

It tends to tear the tail off: http://www.pprune.org/forums/showthread.php?t=154775

- bit late with the 'Cabin Secure, then Rainboe?:) :)

In modern airliners fitted with yaw dampers, rudder input is probably only necessary during crosswind landings / takeoffs, and for directional control during the landing and takeoff roll. ( and to correct for asymetric thrust during an engine failure)

This applies to all aircraft, big and small. When freed from the ground, you have the ability to make turning more comfortable. Instead of being thrown towards the outside of the turn, in an aircraft you can now make this force be felt in a vertical direction by banking the aircraft (by using the ailerons instaed of the rudder). It is also more efficient aerodynamically to do this (less drag) and whilst it is possible to change direction just using the rudder alone, the secondary effect of rudder is bank. This is because the outer wing will have a greater airflow over it and as a result, generate more lift and therefore bank the aircraft anyway.

Amongst other reasons (conected with stability), the yaw damper will also smooth the secondary effects of aileron and as a result provide a smoother ride.

PM

...except that your discourse did not quite answer the OP's question.

The reason that explicit rudder input is not used in modern airliners is, as TotalBeginner noted above, that the yaw damper systems also act as turn coordinators. A second reason is that the combination of spoiler and aileron for roll control negates the adverse yaw that many aileron-only airplanes suffer.

However, MANY (maybe even "most") small airplanes require some amount of rudder input along with aileron to coordinate the turn. In fact, aircraft with long wingspans (e.g., many gliders), turn better with rudder input in advance of the aileron input. This is, again, because the adverse yaw caused by the downward-deflected aileron (more lift => more drag on that side) will otherwise cause an initial yaw in the wrong direction.

thanks alot