chicken6...as wot i rote, the secondary effect of use of ailerons is adverse aileron yaw.
Roll has no secondary effect, it is the motion the aircraft performs when it rotates about its longitudinal axis, whatever may cause that roll.
To demonstrate adverse aileron yaw, select reference point on the horizon, apply aileron without rudder and roll aircraft.
Aircraft nose will yaw in opposite direction to roll.
point out the effect on balance indicator.
Roll back to wings level.
Do same in opposite direction. if student hasn't yet thrown up, could continue this rolling motion to left and right. the yaw will be more evident. Also tell student to look at wing tip (should be maintaining lookout anyway).
The wing tip will magnify the effect of yaw by moving back and forward describing a oval or egg shaped passage through the air.
Rolling left, left wing tip moves forward.. rolling back to wings level, wing tip moves back.
Now repeat with co-ordinated use of rudder, show difference(Nose, wing tip, ball, stomach).
Ultimate demo, max. rate roll, collision avoidance( Watch maneouvre speed!).