Essential Aircraft Autopilot Components

The aircraft autopilot system is a very important technology for safe and efficient flight, allowing for the vehicle to be guided without direct assistance from the pilot. While variations of the device may be found across differing aircraft models, most will include the same basic components, switches, and auxiliary units that enable them to function as intended. Generally speaking, there are four primary elements of the autopilot system, and these include sensing elements, the computing element, output elements, and command elements.

The sensing elements of the aircraft autopilot system are used to detect movements of the vehicle, and they include the turn coordinator, altitude control, and attitude and directional gyros. As movements are detected, the sensing elements will relay electrical signals to the autopilot system so that adjustments can be made as necessary to maintain a set path. For the attitude and directional gyros, such components may either be mounted within the cockpit or remotely. Beyond sending signals to the autopilot computer, many sensing elements will also provide their readings on cockpit displays.

The computer autopilot element serves as the brain of the entire system, and it may be either analog or digital. During typical aircraft autopilot engagement, the computer receives and interprets data from the sensing elements, creates commands and navigational inputs, and then relays instructions to the correlating output elements to make the needed adjustment or change. In some systems, an amplifier may be added in order to create stronger signals for processing as well as may be used by output devices such as servo motors. For an analog computing element, the amplifier and its circuitry serves as the computer autopilot system. Digital systems often feature solid-state technology for their operations, and signals are typically only amplified for output element instructions.

The output elements are the components that actuate control surfaces as directed by the computer, and they come in the form of servos. Depending on how flight controls are actuated, the autopilot servo design may vary. Mechanical systems that utilize cables will often have servo motors or electro-pneumatic servos for actuation. For hydraulic flight controls, electro-hydraulic autopilot servos are the primary type. Lastly, digital fly-by-wire configurations will regularly use the same actuation servos for autopilot as they would for manual control. With each type, it is important to know that servos will primarily utilize commands from the autopilot system when the system is engaged, rather than only those from the pilot. As such, the autopilot system should be disengaged if the pilot desires full governance over all flight controls.

The command element of the autopilot system consists of a command unit known as a flight controller. The flight controller is paramount to the overall operation of the autopilot system as it serves as the medium for the pilot to enable specific settings and engage or disengage the system. With a variety of buttons provided, pilots utilize the flight controller to relay instructions to the autopilot computer so that it can manage all servos. While the controls offered by the flight controller may vary, common commands include setting level flight, climbs, descents, and headings. While an on/off switch is provided on the command element for the means of engaging or disengaging autopilot, another disconnect switch will typically be provided on the control wheel in the case of a malfunction.

With the essential elements of the aircraft autopilot system and autopilot accessories, pilots can be alleviated of some control in order for them to focus on what is most important. As such, ensuring that your autopilot system is functional with reliable components can further ensure the safety of flight operations. At NSN Components, we are an online distributor of aircraft parts with over 2 billion new, used, and obsolete items readily available for purchase. Peruse our part listings today at your leisure, and our team of industry experts are readily available 24/7x365 to provide competitive quotes and assist with the purchasing process as needed.

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1. alex marsh
2. Posted on March 19, 2021
3. aviation

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