Originally Posted by
Outwest
I have wondered as well why we have that button, is it in fact a certification requirement?
Probably not a certification requirement as such, but certification requirements often relate to the outcome rather than the way to achieve it. So for example there might be some requirement relating to safety being ensured with some sort of AP runaway, and an easy way of achieving that is to have a fast disengage button. So it's probably a means of compliance rather than a requirement in itself. But if you have "hung your hat" on that as a means of compliance, it could be difficult to find another means.