Editing Fly-by-wire (section)

=== Legislation ===
The United States [[Federal Aviation Administration]] (FAA) has adopted the [[Radio Technical Commission for Aeronautics|RTCA]]/[[DO-178C]], titled "Software Considerations in Airborne Systems and Equipment Certification", as the certification standard for aviation software. Any [[safety-critical]] component in a digital fly-by-wire system including applications of the laws of [[aeronautics]] and computer [[operating system]]s will need to be certified to DO-178C Level A or B, depending on the class of aircraft, which is applicable for preventing potential catastrophic failures.<ref>{{Cite web|url=http://www.aviationexplorer.com/Fly_By_Wire_Aircraft.html|title=Fly-By-Wire Aircraft Facts History Pictures and Information|last=Explorer|first=Aviation|website=aviationexplorer.com|access-date=2016-10-13}}</ref>

Nevertheless, the top concern for computerized, digital, fly-by-wire systems is reliability, even more so than for analog electronic control systems. This is because the digital computers that are running software are often the only control path between the pilot and aircraft's [[flight control surfaces]]. If the computer software crashes for any reason, the pilot may be unable to control an aircraft. Hence virtually all fly-by-wire flight control systems are either triply or quadruply [[redundancy (engineering)|redundant in their computers and electronics]]. These have three or four flight-control computers operating in parallel and three or four separate [[Bus (computing)|data buses]] connecting them with each control surface.{{Citation needed|date=May 2010}}