Okay, here's an option: you roll crits as normal. The first x (x being the no. of redundancy for the ship) which cause a reduction in speed, AD or impair SAs are ignored (but they are still treated as criticals, and they still do their extra damage). Only the speed/AD/SA reduction is removed.
As has been mentioned before, having a spare engine doesn't stop the first blowing up, it simply stops the ship from grinding to a halt.
As has been mentioned before, having a spare engine doesn't stop the first blowing up, it simply stops the ship from grinding to a halt.