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| A control surface on an airplane is sort of like a wing with an airfoil that can change its shape. In figure 1a the top of the stabilizer-elevator surface is creating a compression effect via deflection while the bottom surface is creating a downward pull (inverse lift) by moving the air farther which creates a lower pressure. This forces the tail down and the nose up. By the nose being pointed up the thrust line of the engine is also pointed up and will pull the airplane skyward. Figure 1b is just the opposite and will cause the opposite to happen. |
| Figure 2 depicts the same effect with the Rudder. In this case a right Yaw will result. |
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Figure 3 depicts this effect with the ailerons. Viewing the plane from the rear, the right aileron is deflected up pushing the right wing down. The left aileron is deflected down pushing the left wing up. This will result in a right bank. In order to control the airplane properly, these three control axis are not usually applied and held in position. They are applied for only a short time to position the airplane in the attitude you desire. For instance, provided you have enough engine power, up elevator is applied and held. The plane won't just keep climbing, instead it will keep pitching the nose up and over making 360 degree loops until the elevator is neutralized. The same holds true for the rudder and ailerons as the airplane will keep yawing and rolling until the respective controls are neutralized. |