Use Aircraft Rudders Correctly

If you fly aircraft, then it is likely that you have been confused by the rudder. Just what does it really do, and how can it be used correctly?

Steps

Know what the rudders are used for. The purpose of the rudder, or tail rotor in a helicopter is to minimise drag mostly, and reduce motion sickness for passengers when maneuvering.
- Drag is minimised by using the rudder to keep the fuselage aligned with the direction of flight. This makes the aircraft present the least area to the air through which it is flying.
- Motion sickness is reduced by using the rudders to prevent the aircraft from wallowing in turbulence - i.e. stopping the aircraft from yawing opposite the direction of roll. This will help to prevent airsickness by reducing the arcing left to right pendulous movement that results from using ailerons alone to maintain straight and level.
Ignore the balance ball and keep your eyes open. The best way to use the rudder correctly in straight and level flight is to ignore the balance ball, and open your eyes wide to take in the picture out the front without focusing on one spot to the exclusion of the "big picture".
The idea is to make sure the wings are level, and this is important, because if the wings are perfectly level, then any tendency to turn is due to yaw. The rudder is used to prevent any heading excursions while coordinating the ailerons to maintain wings level.
- This is more efficient than continually referring to the balance ball because you "take your eyes off the ball" when you look away from the picture out the window.

Imagine the aircraft has a long rod through the propeller spinner coinciding with the roll axis extending to the horizon in both directions fore and aft. Your job is to ensure that the aircraft rolls around this axis only or the rod will dig into the ground in front or behind.
Motion sickness is induced when conflict occurs between what your eyes are seeing, and what your balance organs in the middle ear are sensing. Keeping your eyes focused on the horizon, or some stationary reference point during aerobatics will help reduce the conflict. And keeping your mind off feeling sick will help as well. A passenger who is feeling sick could be given the task of looking out for any conflicting traffic that is in the area, even if there is none advised by ATC. Or you could get them to help you fly the aircraft straight and level for a while if they are in the front seat.

This is intended as advice for training or licensed pilots only. It is intended to aid in understanding of the purpose of the rudder only, and not flight instruction.