Flight Redemptions

What is A/THR in Aviation? (Autothrust)

Updated: February 18, 2024

Autothrust: Enhancing Safety and Efficiency in Aviation

Autothrust, also known as A/THR, is a significant technological advancement in aviation that has revolutionized the way aircraft engines are controlled. This automated system assists pilots in managing engine power and thrust settings, ensuring a smoother and more efficient flight. By taking advantage of this innovative feature, pilots can focus more on other critical aspects of flying, enhancing safety and reducing workload. In this article, we will explore the functionality and benefits of autothrust, as well as its impact on modern aviation.

The Functionality of Autothrust

Autothrust, as its name suggests, automatically controls the thrust produced by an aircraft's engines. It utilizes sophisticated computer algorithms, sensors, and actuators to continually monitor and adjust engine power settings based on various parameters such as aircraft speed, altitude, and pilot inputs.

When engaged, the autothrust system works in conjunction with the flight management system (FMS) and the autopilot. It receives information from the FMS, including the desired speed, climb or descent rate, and altitude constraints. Based on this information, the autothrust system modulates the engine thrust to achieve the desired performance.

One of the key features of autothrust is its ability to maintain a constant airspeed during various phases of flight. For instance, during takeoff, the system ensures that the aircraft reaches and maintains the desired takeoff speed, reducing the workload on the pilots. Similarly, during the climb, descent, and approach phases, the autothrust system adjusts the engine thrust to maintain a consistent airspeed, allowing for smoother and more efficient operations.

Enhancing Safety with Autothrust

The implementation of autothrust systems has significantly enhanced safety in aviation. By automating the management of engine thrust, pilots can focus their attention on other critical tasks such as navigation, communication, and monitoring the aircraft systems. This reduces the chances of human error and allows pilots to respond more effectively to unexpected situations.

Autothrust systems also play a crucial role in preventing stalls and maintaining proper speed margins. In the event of an impending stall, the autothrust system automatically adjusts the engine thrust to increase speed and prevent the aircraft from entering a dangerous aerodynamic state. This feature is particularly valuable during critical phases of flight, such as takeoff and landing, where maintaining a precise airspeed is vital for safety.

Furthermore, autothrust systems contribute to improved fuel efficiency. By optimizing engine thrust settings based on flight conditions, the system ensures that the aircraft operates at the most economical levels. This not only reduces fuel consumption but also minimizes environmental impact by lowering carbon emissions.

The Benefits of Autothrust

Autothrust offers several significant benefits to both pilots and airlines. Let's explore some of these advantages:

1. Reduced Pilot Workload

By automating the control of engine thrust, autothrust systems significantly reduce the workload on pilots. This allows them to allocate more attention to critical cockpit duties, such as monitoring the aircraft's systems, communicating with air traffic control, and making important decisions. Consequently, pilots can better manage their cognitive resources, leading to enhanced situational awareness and improved decision-making.

2. Improved Flight Efficiency

Autothrust systems optimize engine thrust settings based on flight conditions, resulting in improved flight efficiency. By maintaining a consistent airspeed and adjusting engine power as needed, these systems reduce fuel consumption and increase range. This not only benefits airlines by reducing operating costs but also contributes to a more sustainable and environmentally friendly aviation industry.

3. Enhanced Safety and Performance

Autothrust systems enhance safety by minimizing the risk of stalls and ensuring the aircraft operates within safe speed margins. By continuously monitoring the flight parameters and making real-time adjustments, autothrust systems help prevent hazardous situations and improve overall flight performance. This is particularly valuable during adverse weather conditions, where maintaining precise airspeed and control is crucial.

It is important to note that autothrust systems are designed to assist pilots and not replace their skills and expertise. Pilots retain ultimate control over the aircraft and can override or disengage the autothrust system when necessary.


Autothrust, or A/THR, has undoubtedly transformed the aviation industry by automating engine thrust control. This technological advancement has resulted in increased safety, improved flight efficiency, and reduced pilot workload. By maintaining precise airspeeds and optimizing engine power settings, autothrust systems contribute to a smoother and more efficient flying experience. As aviation continues to evolve, autothrust remains a critical component in enhancing flight safety and performance.

For more information on autothrust systems and their impact on aviation, you can visit Boeing's website.

Recent Posts