Editing Fly-by-wire (section)

{{Short description|Electronic flight control system}}
{{Other uses}}
{{More citations needed|date=May 2024}}
{{Use dmy dates|date=October 2023}}
{{Use American English|date=February 2022}}

[[File:Airbus-319-cockpit.jpg|thumb|The [[Airbus A320 family]] was the first [[airliner]] to feature a full [[glass cockpit]] and digital fly-by-wire flight control system. The only analogue instruments were the [[Radio direction finder#Radio-magnetic indicator (RMI)|radio magnetic indicator]], brake pressure indicator, standby altimeter and [[artificial horizon]], the latter two being replaced by a digital [[integrated standby instrument system]] in later production models.]]
'''Fly-by-wire''' ('''FBW''') is a system that replaces the conventional [[aircraft flight control system#Hydro-mechanical|manual flight controls]] of an aircraft with an electronic interface. The movements of flight controls are converted to electronic signals, and [[flight control computer]]s determine how to move the [[actuator]]s at each control surface to provide the ordered response. Implementations either use [[Aircraft flight control system|mechanical flight control]] backup systems or else are fully electronic.<ref name=suth >[https://web.archive.org/web/20200115234428/https://apps.dtic.mil/dtic/tr/fulltext/u2/679158.pdf Fly by Wire Flight Control Systems] Sutherland</ref>

Improved fully fly-by-wire systems interpret the pilot's control inputs as a desired outcome and calculate the control surface positions required to achieve that outcome; this results in various combinations of [[rudder]], [[Elevator (aeronautics)|elevator]], [[aileron]], [[Flap (aeronautics)|flaps]] and engine controls in different situations using a closed [[Feedback#Electronic engineering|feedback]] loop. The pilot may not be fully aware of all the control outputs acting to affect the outcome, only that the aircraft is reacting as expected. The fly-by-wire computers act to stabilize the aircraft and adjust the flying characteristics without the pilot's involvement, and to prevent the pilot from operating outside of the aircraft's safe [[performance envelope]].<ref name="Crane">Crane, Dale: ''Dictionary of Aeronautical Terms, third edition'', page 224. Aviation Supplies & Academics, 1997. {{ISBN|1-56027-287-2}}</ref><ref name=unstable/>