Originally posted by HarryC
I see a previous post recommends that you approach at an angle to the runway then use rudder to straighten up to the runway. Clearly if you have a 3 channel trainer then all you have is rudder, but apart from this special case (and there canĘt be many 3 channel trainers left these days) you should never never ever use rudder as a means of turning an aeroplane. Rudder does not turn a plane. A turn comes from banking the wing so that the inclined lift changes the direction of travel, the fin then tries to keep the plane straight into the new direction of the airflow like the flights on a dart. A turn always comes from banking, not from yawing. Use of rudder at low speeds is asking for a spin. The rudder is there to assist the fin in keeping the plane aligned into the airflow, known as balanced flight, not to push it out of balance except in aerobatic manoeuvres.
Harry
Sorry just plane wrong.
Rudder controls yaw, which is turning within the plane formed by the pitch axis line and the roll axis line. While its true you turn tighter by rolling then using pitch control to convert lift into a turn, the rudder will still give plenty of turning control.
Use of rudder should be stressed durring training on landings. At low airspeed the ailerons can cause severe adverse yaw effect and can cause a violent tip-stall on some planes. You won't see this problem as much with a 4-ch trainer, because the design is intended to prevent it from happening. Try using ailerons and no rudder for an approach with a heavy scale warbird... you'll be picking up pieces. Failure to learn to use the rudder is one reason for a lot of model aircraft crashes. Low, slow and using ailerons for correction is often a recipe for disaster.
The rudder can sometimes save you in case of aileron system failure too.