Dennis and netters The reason that some planes can "lift" a wing in slow flight while others can't has to do with a long "arm" or simply the leverage that the rudder has due to the length of the tailboom. Although some of the trainers allow for use of the rudder alone to lift a wing during slow flights and stalls, this is mainly done by CFI's in training to build control confidence in the student so that the student gets used to small inputs, and being smooth, not because the rudder is the preferred control device. Some ultralights fly with only rudder and elevator due to their slow speeds allow for the application of rudder to make a turn which momentarily skids the plane, but slows the in board wing causing it to drop, while speeding up the out board, causing it to lift. The trainers do the same thing, and can "get away" with using this uncoordinated approach to turning. It is also to build confidence in the student for later spin recovery if ever it has to be done. Application of ailerons then will only cause a tighter spin. By design the rudder is only used to maintain coordinated flight to correct for yaw.
The wing washout is by design an attempt to maintain some aileron effectiveness as the aircraft slows down. Not always can they maintain positive aileron control near the stall, but that is the effort anyway. It is also more primarily apart of the design to insure that the stall occurs at the wing root, and not the tip so that the stall characteristics will be more forgiving, and more control is preserved than would be otherwise, (stall occurring at the wingtip first). Colin Rainey Sanford, FL