Autopilot on Airplanes
posted Wed Jan 17, 2024 by Ceci Mungovan
Autopilot is a type of system used to direct the plane on a set course that doesn’t need constant adjustments or guidance from a human. It is predominately used on passenger planes. Autopilot basically keeps the plane stable, flying in the air and on its predetermined path. It can be faster to respond and make more precise adjustments than a human pilot. It is usually switched on after takeoff and switched off before landing. In some rare cases, it can perform a landing independently, but there are very strict criteria for scenarios where that would happen. If there is low visibility, the autopilot can assist the pilot in the landing by using sensors and GPS. Autopilot can also help in the climb to cruising altitude after takeoff.
There are different types of autopilot, depending on how many movements of the plane that it can affect, called axes. The most basic type of autopilot can only influence one element, called a single axis. The maximum is three because there are three different directions a plane can maneuver. The three motions are pitch, yaw, and roll. Pitch rotates around the y-axis, yaw rotates around the z-axis, and roll rotates around the x-axis.
There are sensors on the plane to detect changes in movement. The sensors send information to the autopilot software. For example, if the plane started tilting to the left, the sensors would detect that and send a signal to the system. Then, the autopilot would adjust accordingly to level off the plane. Once level again, the autopilot would stop that movement to avoid over-adjusting the plane to tilt to the right.
Autopilot is a part of the other software on the plane, called flight management system (FMS). FMS provides all the data needed to control the plane. It is used to provide information on all of the factors that can influence air travel. Flight management systems incorporate the features needed for a flight to be successful, getting from point A to B. It is the plane’s equivalent of a car’s GPS, like Google Maps. FMS are made up of multiple machines that all work together. Its most crucial job is handling navigation and flight plans. The system is used to calculate trajectory during the flight based on outside factors and the pre-determined flight plan, and manages global air traffic and keeps track of where planes are in relation to each other. Before FMS existed, planes needed to have flight engineers and navigators on board to do these things.
Autopilot isn't perfect, and sometimes it can malfunction. The most common malfunctions are in servos, mechanisms that detect and correct errors in delicate machines on the plane. It helps the mechanisms move and stay aligned. The motor can break or there can be issues with the connection between the parts. The sensors responsible for telling the position of the plane can also fail. In these cases, the pilot would turn the autopilot off and operate the plane manually. Autopilot error is rare though, and it still makes fewer mistakes than human pilots do. Around 80% of error are human errors versus 20% being caused by mechanical problems. Without autopilot, the pilot would have to make all of the fine adjustments that are constantly required to keep the plane level and in the air. This would be very difficult because of all the different variables that exist in flying a plane. It is mentally taxing and leaves a lot more room for error. Autopilot makes air travel easier for everyone from the passengers, to the pilots, and air traffic controllers.