Turns are more complex than they look. There are a few things to do in a turn and they are all very important.
An airplane turns by banking to the side. This bank allows some of the lift from the wing to pull the airplane in the direction of the turn.
But there is more to it. In fact, turning an airplane requires simultaneous use of the ailerons, rudder, and elevator controls.
But using some of the lift to turn means less lift to keep the airplane flying. So maintaining a constant altitude in a turn, requires some additional back pressure on the yoke, so the aircraft pitches up and the wing produces more lift. The amount of back pressure needed varies with the turn. Less than 15 degrees of turn requires almost no back pressure, while 30 degrees of bank or more requires a noticeable amount of back pressure.
Another issue while turning concerns the ailerons. Before I explain it, note that a turn requires the pilot to use the ailerons to bank the plane, but then when the plane reaches the desired bank, the ailerons are moved back to the neutral position. To take the airplane out of the bank, the pilot moves the ailerons away from the direction of the turn and then back to neutral when the wings are level.
Any time that the ailerons are moved they affect the airplane. The aileron is raised to reduce lift on the wing to be lowered. The other wing needs to be raised and the aileron there is lowered, pushing more air down and increasing lift. But with lift comes drag. There are two types of drag but we will focus on induced drag, which is the one that is proportional to lift. As lift increases, drag increases.
All this means that the wing being raised has more drag and the wing being lowered has less drag while entering a bank. Once established in the bank the differential drag is not a factor because the ailerons are neutral again.
This means that an aircraft banking to the left will experience an increase in drag on the right wing while moving into the bank.
This is another force to counteract, and the rudder is the tool for the job. While rolling into a turn push a small amount of rudder in the direction that you are turning. So overall the aileron and rudder should be moved in the same direction.
How much rudder is needed can be detected by feeling the airplane pulling your body to one side or the other, or looking at “the ball”, or inclinometer. If the inclinometer is not centered you will feel your body being pulled to the side, just like in a car.
To correct for this, if you aren’t sure which way to move the rudder, just remember: Step on the Ball!
If the ball in the inclinometer is to the left of center, then you will feel a pull to the left. Apply more left rudder and center the ball, and you will not feel a pull in either direction. That is why a plane can turn without the passengers feeling it happen.
Practice is the key to making smooth turns using the ailerons, rudder, and elevator. Eventually, this can come naturally and you won’t have to think about it.
If you are turning to a given heading, say directly north, and you keep the plane banked at 30 degrees until you reach a north heading, you will end up heading 015 or 345 degrees. Why? Because the plane continues to turn as you roll out of your bank. Luckily there is a simple rule of thumb that is very reliable.
Lead you rollout by half of your bank angle.
If you are banking with a bank of 30 degrees then start rolling out 15 degrees before you reach the desired heading.
The video below has more info about the marking on a standard attitude indicator that show bank angle.
Look before turning
It is natural to look in the direction that you intend to go. Don’t fall out of this habit in an airplane because the sky isn’t always as big as you think. In a high-wing airplane you need to look before you turn since you will not be able to see to the side while turning.
Lift the wing by banking away from your turn initially. Verify that another airplane is not there and then begin your turn. Do not neglect this habit, even in the simulator, because it is a habit and it will be harder to pick it up later.
Watch the video below to see an overview and demonstration of this information.