Originally Posted by
bill fly
So when designing on probabilities of failure, it isn’t enough to examine a single system or to presume that everything else in the cockpit is normal. Some basic design rules need looking at here.
This raises an important question of 'grandfather' certification with a new model variant. When one change is made, does every other system on the aircraft need to be considered from scratch?
In retrospect this should have been done, and the facts are now beyond doubt. The regulatory details may not be clear, or subject to interpretation.