I was reading about the ERCO aircraft which apparently has a rudder-aileron linkage system that enables co-ordinated turns without the need for explicit rudder inputs. I've heard of Piper's having bungee cords for the same purpose.
Does such a physical linkage lead to perfectly co-ordinated turns under all conditions? Or is it only a coarse approximation & a skilled pilot can execute a better turn?
Why don't a lot more civil aircraft automate this co-ordinated turn feature? Is it because it is hard to automate or more that one wants the pilot to retain the ability to slip when necessary & execute un-coordinated turns sometimes?
Well, even if the latter were true, since 99% of all turns are co-ordinated one could just offer an override for the automated co-ordination feature, right?
A physical linkage is rather crude, but with a servo / feedback loop wouldn't it be possible to entirely eliminate the rudder pedals?