ExSp33db1rd summed it up very well:
it's AGEING that's the problem, not the AGE.
I've just lost my Class 1 ( but not yet Class 2 ) due to medical issues related to ageing, I've no problem with that. S**t happens.
Competency is the issue. It is
impossible to use any specific age as a point where competency ends (or begins for that matter). Degradation in competency occurs from ageing of course, as well as disease, lifestyle, and other factors.
Old F*rts lke ExSp33db1rd (and me) understand that we are degrading (in too many ways!) and we acknowledge that -- and accept it. But it
can be assessed (as in his example re Class 1 v/s Class 2).
grizz