How Planes Control their Direction Airplanes have three axis of rotation. They are the longitudinal, vertical, and lateral axis. The longitudinal axis is what allows an airplane to turn. The lateral axis is what allows the airplane to pitch up and downwards so that the airplane can gain or loose altitude. The vertical axis is what allows the plane to be looking in the same direction in which it is actually moving/turning in. The control surfaces on the wings and empennage allow the motion on these axis to be controlled. The ailerons control the roll on the longitudinal axis by allowing one wing to have more lift than another. The elevator on the horizontal stabilizer "varies the amount of force generated by the tail surface and is used to generate and control the pitching motion of the aircraft" according to NASA. The rudder on the vertical stabilizer which is also part of the empennage allows the yaw movement on the vertical axis. At the point where all three axis meet is the center of gravity of the plane. It is very crucial that the center of gravity is in the correct spot in the plane (noted by manufacturer) because if it isn't, the plane will not fly in a stable matter making the flight unsafe, or it just won't fly at all.