Multiple redundant flight control systems have been the subject of continuous development since the 1950s. Early examples include the automatic landing systems of the BAC 1–11 and the VC10; these were followed by the full flight envelope control systems fitted to the Concorde and Tornado. These examples all use analogue computing techniques, with redundancy levels appropriate to the individual fail-passive or fail-operational requirements of each system.

However, recent advances in digital technology have enabled highly sophisticated flight control systems to be implemented which would be wholly impractical using analogue computing methods. Furthermore, digital computing is amenable to self-monitoring techniques which can be used not only to improve system maintainability, but also to augment the cross comparison or majority voting algorithms which have been developed on analogue systems.