What is FBW on Boeing 737? (Fly-By-Wire)

Fly-by-Wire (FBW) is an advanced electronic flight control system that has revolutionized the way aircraft are flown. It replaces the conventional mechanical systems with electronic ones, allowing for greater precision and control. The Boeing 737-800, a popular commercial aircraft, has also adopted this technology, enhancing its safety, efficiency, and performance.

FBW on the Boeing 737-800 is an integral part of the aircraft’s flight control system. It uses computers to translate pilot input into electronic signals, which are then sent to actuators that move the control surfaces. This allows for a more direct and precise control of the aircraft, reducing the workload for pilots and enhancing flight safety.

One of the key advantages of FBW is its ability to provide automatic flight envelope protection. This feature prevents the aircraft from exceeding its structural limits and operating outside its safe flight envelope. The FBW system constantly monitors the aircraft’s performance and applies necessary corrections to keep it within safe parameters. This adds an extra layer of safety, especially during challenging flight situations.

Furthermore, FBW enables the Boeing 737-800 to have features like autothrottle and autopilot, which enhance the aircraft’s performance and operational efficiency. The autothrottle system automatically controls engine power, adjusting it according to the flight conditions and desired speed. This ensures optimal fuel efficiency and reduces pilot workload. The autopilot system allows the aircraft to fly on a predetermined course, making precise flight path adjustments and reducing the pilot’s workload during long-haul flights.

Overall, FBW on the Boeing 737-800 brings numerous benefits to both pilots and passengers. It enhances safety by providing automatic flight envelope protection and reduces the workload for pilots through features like autothrottle and autopilot. The precision and control offered by FBW also result in smoother and more comfortable flights for passengers.

How does Fly-by-Wire work?

Fly-by-Wire works by replacing the traditional mechanical connections between the pilot’s controls and the aircraft’s control surfaces with electronic signals. The pilot’s input is translated into electrical signals by sensors and then transmitted to the flight control computers. These computers process the signals and send commands to the actuators, which in turn move the control surfaces to achieve the desired aircraft response.

The digital nature of Fly-by-Wire allows for greater precision and accuracy in controlling the aircraft. It eliminates the potential for mechanical interference or degradation, resulting in more consistent and reliable flight control. The system also provides feedback to the pilot through electrically-driven control inputs, giving a sense of the aircraft’s response.

The Fly-by-Wire system on the Boeing 737-800 uses redundant computer systems for increased reliability. This means that multiple independent computers are constantly cross-checking each other’s output, ensuring accuracy and enhancing the system’s fault tolerance. In the event of a computer failure, the FBW system seamlessly transfers control to a backup system, further enhancing the aircraft’s safety.

Benefits of Fly-by-Wire on the Boeing 737-800

The adoption of Fly-by-Wire technology on the Boeing 737-800 has brought several benefits that positively impact the aircraft’s performance, safety, and efficiency.

1. Enhanced Safety

Fly-by-Wire system provides automatic flight envelope protection, preventing the aircraft from entering unsafe flight conditions. It constantly monitors the aircraft’s behavior and takes corrective actions to keep it within safe limits. This feature reduces the risk of human error and ensures the aircraft operates within its structural limits, enhancing overall safety.

2. Improved Efficiency

FBW enables the Boeing 737-800 to have advanced features like autothrottle and autopilot, which contribute to operational efficiency. The autothrottle system optimizes engine power, leading to fuel savings and reduced emissions. The autopilot system allows for precise flight path control, minimizing deviations and optimizing flight routes, resulting in reduced fuel consumption and improved overall efficiency.

3. Enhanced Control and Maneuverability

Fly-by-Wire provides precise and direct control over the aircraft’s flight surfaces. It eliminates mechanical linkages, which can introduce friction and imprecision. This results in improved control responsiveness, making the aircraft more maneuverable and enhancing its handling characteristics. Pilots can execute precise maneuvers and adjustments, leading to safer and smoother flight operations.


Fly-by-Wire technology has significantly enhanced the performance, safety, and efficiency of the Boeing 737-800 aircraft. Its advanced electronic flight control system provides automatic flight envelope protection, improved fuel efficiency through features like autothrottle, and precise control and maneuverability. For pilots and passengers alike, Fly-by-Wire has transformed the way commercial aircraft are flown, ensuring a smoother, safer, and more comfortable travel experience.

For More: What is TMS on Boeing 737? (Thrust Management System)