Fly-by-Wire

Fly-by-Wire (FBW) is a flight control system in which the pilot's control inputs are converted to electronic signals and transmitted by wire to flight control computers, which then command hydraulic actuators to move the control surfaces. There is no direct mechanical linkage between the cockpit controls and the flight surfaces.

Advantages of fly-by-wire include:

• Envelope protection: The computers can prevent the pilot from exceeding safe flight parameters (excessive angle of attack, G-loads, or bank angles)
• Weight reduction: Electronic wires are lighter than mechanical cables, pushrods, and pulleys
• Optimized control: Computer-mediated control allows for aerodynamically unstable designs that offer better fuel efficiency
• Redundancy: Multiple independent computer channels provide fault tolerance

The Airbus A320 (1988) was the first commercial fly-by-wire aircraft. Today, virtually all modern airliners use FBW systems, including the Boeing 777, 787, Airbus A320/A330/A340/A350/A380 families. The two manufacturers have different FBW philosophies: Airbus uses hard envelope protections that the pilot generally cannot override, while Boeing allows the pilot to override protections with sufficient force.