Airplane Flight Controls

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There are three primary flight control surfaces: the ailerons, rudder, and elevators. These control movement of the airplane around three corresponding axes: the vertical, longitudinal, and lateral. Figure illustrates the three axes of movement. These axes intersect at the airplane’s center of gravity.

Yaw is movement about the vertical axis—the nose appears to swing to the pilot’s left and right. Yaw is be controlled with the rudder via the rudder pedals. Roll takes place around the longitudinal axis and is controlled by the ailerons. Finally, pitch, or the movement of the nose up or down, as perceived by the pilot, takes place around the lateral axis, as governed through the elevators. As you will come to understand as you read through this book, understanding the correct use of flight controls—and how control inputs will affect the attitude, airspeed, and control of the aircraft—is one of the basic fundamentals to becoming a safe, competent pilot.

Figure depicts the ailerons, rudder, and elevator. This is the standard arrangement for most general-aviation airplanes. There are variations, such as the Beechcraft Bonanza, which has a V-tail, and some planes incorporate spoilers on the wings as opposed to ailerons, the Mitsubishi MU-2 being an example, and there are even a few with the elevators at the front, as in the Beechraft Starship, in a canard arrangement, but these represent the minority. 

Each of these flight surfaces is controlled by the pilot from inside the cockpit. Ailerons are controlled by the control wheel, or stick in some aircraft, through turning the control wheel or moving the stick from left to right. To roll the plane to the left, you turn the control wheel to the left; to roll right, you turn the control wheel to the right.

If the plane you are flying has a control stick, then lateral movement of the stick to the left or right rolls the plane to the left or right. Figure illustrates how ailerons cause the plane to roll. As you can see, in a roll to the left the right aileron moves down, while the left aileron moves up. We learned earlier in the chapter that greater camber on the airfoil generates more lift. The ailerons essentially increase the camber of the wing that has the lowered aileron, which increases lift for that wing. The wing with the raised aileron suffers from a reduction in lift, the end result in this example being that the right wing is generating more lift than the left wing. This imbalance in lift generated by the wings causes the right wing to rise and the left wing to drop. As a result, the airplane rolls to the left about the longitudinal axis. The same holds true for rolls in the opposite direction.

The elevator is also manipulated through the control wheel with forward and backward movement. Pulling back on the control wheel, or yoke, raises the nose of the airplane; moving the yoke forward lowers the nose—as depicted in Figure. 

As with the ailerons, pitch control through the elevators results from lift variation at the control surface.

Figure shows movement of the rudder to the left and right generating changes in camber, and lift, just as with the other flight controls. Like the other motions, this movement takes place about the plane’s center of gravity.

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