Originally Posted by
Volume
Unfortunately younger engineers do no longer believe in true (hardware) redundancy... On some modern aircraft there is no more physical positive/negative relief valve, there is just a software function in the outflow valve controller, which operates the failed outflow valve in case the outflow valve or the controller fails... We will probably learn one day, that this is not the best idea.
Could you give an example?
The newest type I know is the CSeries and it has both software protection and 2 safety valves and an extra inward relief valve.