Others have commented on here before about how that idea is incorporated into flight control systems.
Here's an example with the Boeing 777 that uses separate architectures:
>The aircraft has triple redundant digital autopilot and flight director designed by Rockwell Collins. The BAE Systems (formerly Marconi Avionics) triple digital primary flight computers provide control limits and commands flight envelope protection. Each of the three primary flight computers contains three different and separate set of 32-bit microprocessors, Motorola, Intel and AMD, to manage the functions of fly-by-wire.