catastrophic probability.
Hydroman400: 532: Sorry, I don't get it. 10^(-7) by 1/20 catastrophic gives 5*10^(-9) per engine . Now you have to multiply by the number of engines, 4, and you get 20*10^(-9) which is 2*10^(-8). Not nearly as good as 1*10^(-9). Per ChristiaanJ, it's still not certain what timespan the original 10^(-7) applies to.
DevX, VFD: Thanks for the EEC power details. I'm still not clear whether the [various] shutdown signals come over a data bus or on wire discretes. If they're on wire discretes, are they routed separately in the wing?