The Primary Movements of Aircraft
There are six main types of motions within the various phases of flight: three in which airplanes must combine the movement with the power applied, and another three relative to the axis:
Climb
This is one of the movements which combines the displacement of the aircraft with the power applied. In this case, the pilot applies increased speed so that the plane can take off from the ground and gain altitude.
Descent
While power is increased during the climb, the opposite is evident during the descent. By decreasing speed in a controlled manner, altitude is lost to reach the destination and facilitate the landing maneuver.
Turning
The turning movement involves numerous pilot skills: selecting the bank angle, yaw angle, pressure control, applied speed and altitude, pedal use, etc. There are different types of turns depending on their intensity and speed.
Pitching
Now we move on to the movements of airplanes relative to their imaginary axes. To talk about pitching, we must first talk about the airplane’s transverse axis – that is, the axis that runs across the width of the airplane, from wingtip to wingtip. Pitching is the rotation of the airplane relative to its transverse axis, the upward or downward movement of the airplane’s nose. It´s carried out by the elevator, usually located at the rear of the airplane, to control altitude.
Rolling
Now we need to focus on the longitudinal axis, which runs from the nose to the tail. The movement an aircraft makes along this axis is called roll, and this motion is produced by the ailerons, the hinged flight-control surfaces forming part of the trailing edge of each wing. When these ailerons are turned, the difference in lift between the wings causes the aircraft to tilt left or right. It´s used in maneuvers such as changing flight direction, the aforementioned turns, or, in the event of turbulence or crosswinds, to maintain stability.
Yaw
The imaginary axis we should focus on in the yaw motion is the vertical one: it would pass through the aircraft’s center of gravity and would be perpendicular to the transverse and longitudinal axes. Yaw is the left and right movement of the aircraft’s nose, controlled by the rudder, and It allows for trajectory control and is one of the movements involved in turns. (Incidentally, in Spanish it´s referred to as a guiñada – “wink” – because it´s similar to the alternate blinking of the left and right eyes.
3 of the Quirkier Terms
Not all aircraft movements are voluntary or desirable, which doesn’t mean they can’t be controlled. In fact, speaking of peculiar movements, it’s fitting to mention one that’s involuntary and another that compensates for it.
Dutch Roll
This is a movement usually caused by a disturbance, such as a gust of wind. It consists of an oscillation of the aircraft, both yaw and roll (i.e., it moves left and right), as if forming a figure eight in the air, and bears some similarity to the movement of ships on the high seas. Why is it known by this name? It´s not at all clear, but one school of thought holds that it has to do with the first Dutch sailors who landed in the so-called Dutch East Indies (now Indonesia) and the sensation that the ground was moving after a long time at sea (commonly known as “land sickness”). But another relates it to the rhythmic swaying movement in a style of Dutch ice skating. Be that as it may, it´s not a good thing, but can be corrected by another movement, this one voluntary:
Yaw Damper
Faced with a safety hazard such as the Dutch roll, this is a system specifically designed to eliminate it through a complex system integrated into the autopilot. What if the autopilot doesn’t engage? No problem, because the yaw damper is constantly working, regardless of whether the autopilot is engaged or not. What’s more, no plane takes off without this function in operation. As we always say, safety on board an airplane is paramount!