.. that would seem to imply that FCS is software, it is a lot more than just that! This is one design for example showing some of the components-
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FCC- Flight Control Computer
FCS- Flight Control System
OSAS- Output Signal Analysis & Selection
ISAS- Input Signal Analysis & Selection
CLAW- Control Law
The FCS consists of four individual FCCs, and each FCC includes a single OSAS, ISAS, and CLAW component, as well as several other components, includes logic for fault tolerance etc.
The Airbus A380
fly-by-wire flight control system has quadruplex redundancy i.e., it has five flight control computers where only one computer is needed to fly the aircraft. Consequently, an Airbus aircraft can afford to lose four of these computers and still be flyable. Of the five flight control computers, three are primary computers and two are secondary (backup) computers.
The primary and the secondary flight control computers use different processors, are designed and supplied by different vendors, feature different chips from different manufacturers, and have different software systems developed by different teams using different programming languages. All this redundancy reduces the probability of common hardware- and software-errors that could lead to system failure.
The multiple redundant flight control computers continuously keep track of each other’s output. If one computer produces deviant results for some reason, the flight control system as a whole excludes the results from that aberrant computer in determining the appropriate actions for the flight controls.
By replicating critical sensors, computers, and actuators, Airbus provides for a
“graceful degradation” state, where essential facilities remain available, allowing the pilot to fly and land the plane. If an Airbus loses all engine power, a
ram air turbine can power the aircraft’s most critical systems, allowing the pilot to glide and land the plane (as happened with
Air Transat Flight 236.)
In my case study of the Boeing 737 MAX aircraft’s anti-stall mechanism, I examined how relying on data from only one Angle-of-Attack (AoA) sensor caused two accidents and the aircraft’s…
www.rightattitudes.com
Finally the significance of RSS in FCS
RSS is probably one of the largest technical advances on the F-16, simply means that the aircraft is balanced in the pitch axis for subsonic flight conditions such that the center of lift for the wing is at, or ahead of, the center of gravity. Therefore, it is necessary for the tail to be a lifting tail. Even though RSS concept allows reduced structual weight and higher T/W, the RSS system will diverge immediately if pitch stability augumentation is not continuously active.
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