Home  Blog  what is a fly-by-wire flight control system?

What Is a Fly-By-Wire Flight Control System?

If you have ever wondered how a pilot gives input on the control stick, yoke, or  rudder, then this blog is for you. Traditionally, airplanes had steel wires running from the control column to the ailerons, elevators, and rudders. The ailerons control roll, the elevators control pitch, and the rudders control yaw. Roll, pitch, and yaw define the movement of aircraft on three different axes, and the combination of these controls is what allows pilots to have a successful flight.

When a pilot pulls the control stick back, the aircraft can carry out different movements. On older jet aircraft, the control columns were connected to a series of high tension cables and pulleys, allowing pilots to manually maneuver the flight control surfaces. In fact, the Cessna 172 is a trainer aircraft that still takes advantage of mechanical flight control systems. Even large jets used to benefit from such systems until they were later transitioned into Hydro-Mechanical flight controls that utilized hydraulic pumps to assist pilots.

Fly-by-wire is just one example of a modern flight control system with an electronic interface that replaced the manual flight controls found in traditional systems. In a fly-by-wire system, the pilot’s input is converted into electronic signals that are transmitted via wires, and it uses a computer to determine how to move each control surface in order to achieve the desired performance from the aircraft. Today, fly-by-wire systems have been improved to interpret the pilot’s control input as the desired outcome and calculate the control surface activities necessary to achieve the desired ends.

Early mechanical flight control systems were heavy, and the high tension lines that controlled the surfaces experienced continuous wear, making them susceptible to snapping from fatigue stress. If the tension lines snapped, this would cause the aircraft to crash as there are no backup systems. Instead, this control system relied on the pilot’s muscle power to fight the control sticks during unconventional situations like wind-shear or stalls. Obviously, this made it unsafe in many large jet aircraft. As such, the Hydro-Mechanical control system provided a feasible solution.

The first airliner that utilized a fly-by-wire system was the Avro Canada CF-105 Arrow in 1958, followed by the Concorde in 1968. The Concorde’s fly-by-wire system contains solid-state components and system redundancy, alongside computerized navigation, automatic search and tracking radar features, and feedback mechanisms to keep pilots informed. The most modern version of fly-by-wire systems based on control laws can be found in the A320, which is equipped with a full glass cockpit.

To operate a fly-by-wire system, a pilot commands the stick to make the aircraft carry out a certain maneuver. Meanwhile, the flight control computer calculates and issues those commands to the electronic controllers for each surface. The controllers at each surface receive these commands and move actuators attached to the control surface until it has moved in the desired direction. The controllers measure the position of each surface with sensors like LVDTs. Aircraft with fly-by-wire systems are furnished with many sensors and gyroscopes to sense small movements in pitch, yaw, and roll and maintain stability.

If you find yourself in need of aircraft parts and components that you can steadily depend on for your operations, rely on ASAP AM Spares. ASAP AM Spares has an ever-expanding inventory with over 2 billion items, all of which have been vetted for fit and function. Get started today to see how we can fulfill your operational needs!


Recent Twitter Posts