Windy, when speaking about a separate soft which accesses the FSX ingame failure 'generator' or just fails certain systems, I think there is such a thing. At least partially and perhaps in a setup together with a career mode of some kind.

Now those things access what FSX offers, so it won't go as deep as a light bulb or certain CBs but it'll stay at e.g. engine 1 failure or a non working gear. Now some addons allow a sort of instructor station to access them, so one can really fail a subsystem or cause wonky freqs on the power generation. So this would go in the direction of my or our dream, a fully workable and maintainable 707.  :D

Now I don't know if there would be a market for something like that to be honest. Well, I never thought that there is a market for flight sim addons, just a few years back.  :-[