Flight Training - Three Lessons From Steep Turns

I was asked the question, "Why can't I keep my bank angle and speed steady in 45 degree turns?"

While this question looks quite simple, it is a very good one. There are several very useful concepts you can learn by understanding what happens in a constant altitude, constant airspeed 45° bank.

Let's assume that you enter a left turn by coordinating your aileron and rudder. As your angle of bank increases you have to pull back further on the elevator control. Once the bank approaches 45°, you once again coordinate your aileron and rudder movement to stop the roll and maintain a constant bank but you must continue pulling back on your elevator control.

1. Where you look now is very important. Most important is that you notice where the horizon cuts the top of the instrument panel. A quick glance at the artificial horizon will verify that you are indeed at 45 degrees. In most airplanes, that tiny white ball in the center of the artificial horizon instrument will be just slightly above the instrument's horizon. But be careful: don't stare at that instrument.

Now glance at the altimeter quickly. Is it moving? Verify that the ball has been centered. Before you move any controls, look out the window straight ahead. Then adjust your angle of bank and pitch attitude. One more time take a quick scan of the instruments. Keep this scan going. But spend most of your time looking outside.

Notice that I did not include the airspeed indicator in your scan. It is not important. If you hold altitude and bank constant, your airspeed will settle down and quit moving.

Interestingly enough, your aileron and rudder controls are to the right of neutral even though you are in a left turn. When you turn left your right wing inscribes a bigger circle through the air than your left wing. So it must travel faster. Since it is going faster, it produces more lift. Of course, when the right wing produces more lift than the left wing the airplane wants to roll to the left. So you must deflect the left aileron down and the right aileron up. In other words, you must keep the aileron control slightly to the right of neutral in a left turn.

2. Now you know that airplanes are unstable in roll. The fact that it wants to increase its bank once a bank has been established and the airplane is turning tells you this. So it requires your input to keep the bank from increasing.

It may not be obvious but you are in a slight pitch up angle of attack. This is because your airplane must lift 141% of its weight. The increased angle of attack causes P-factor. Just as you must compensate for P-factor in a climb, you must compensate for P-factor in a steep turn. That is why you must push on the right rudder pedal. So there you are: turning left even though you are keeping the rudder and aileron to the right of neutral. Steep turns to the right are not exactly symmetric to steep turns to the left. P-factor persists. More often than not you will find that you are pushing on right rudder pedal in a right turn even though your aileron control is slightly to the left of center.

Steep turns, like any other realm of flying, require that you move the controls to adjust the airplane's attitude. You should not move your controls to some pre-conceived position but only to change attitude.

3. The absolutely most useful lesson to learn from tight turns is to fly the airplane by controlling its attitude not by moving its controls to some preconceived position. By comparison, the facts that you eventually put the controls in a position opposite to the direction of turn to maintain a steady bank and that an airplane is unstable in roll are just curiosities.

Executing steep turns is an important and useful skill to master. It is also an essential exercise when becoming familiar with an airplane.

Doug Daniel is a long time pilot, flight instructor, software engineering manager and author. His department developed the software for the out-the-window-displays for the space shuttle, F-117, RS-71 and numerous other exotic airplanes. His writing focuses on flying techniques designed to make flying easier and safer. If this was interesting, visit his website at http://PrivatePilotTrainingOnline.org.