Axes of an Aircraft

in Physics

An airplane in flight is controlled around one or more of three axes of rotation. These axes of rotation are the longitudinal, lateral, and vertical. On the airplane, all three axes intersect at the center of gravity (CG). As the airplane pivots on one of these axes, it is in essence pivoting around the center of gravity (CG). The center of gravity is also referred to as the center of rotation.

On the brightly colored airplane shown in Figure 3‑60, the three axes are shown in the colors red (vertical axis), blue (longitudinal axis), and orange (lateral axis). The flight control that makes the airplane move around the axis is shown in a matching color.


Figure 3-60. The three axes of an airplane.

Figure 3-60. The three axes of an airplane.

The rudder, in red, causes the airplane to move around the vertical axis and this movement is described as being a yaw. The elevator, in orange, causes the airplane to move around the lateral axis and this movement is described as being a pitch. The ailerons, in blue, cause the airplane to move around the longitudinal axis and this movement is described as being a roll.