"very nearly like" is also extremely dangerous when it comes to risk prevention. People are pattern-matchers, and if 99% of flying the plane is the same except

"very nearly like" is also extremely dangerous when it comes to risk prevention. People are pattern-matchers, and if 99% of flying the plane is the same except the part that will kill you if you don't do it the new way--well, people will do it the old way and die. That's infinitely more true in an emergency situation where you tend to fall back strictly on training and instinct. If you want to jar people into different behavior, the interface needs to be different as well. Otherwise it looks like the same old contract. I think many of us kind of know this from GUI/API/whatever design, but there's no reason jet planes would be any different.