Originally Posted by
Rainboe
With horizontal stabilators, the structure passes through the fuselage and is structurally easier to support. A moving fin would just be a pivot with the flight control above it. It would take a lot of fuselage strengthening to prevent deformation and to support a whole moving fin, for a structure that would not get a great deal of use. A rudder on the end of the fin does a satisfactory job- a whole moving 'finilator' would be far heavier, and still end up weaker. I know of no aeroplane at all that uses this solution.
Well, one advantage of a stabilator over elevators in the rear end of a fixed tailplane is alleged to be that shocks might limit elevator effectiveness, whereas moving the whole tailplane up to leading edge is alleged to be better.
But the same reasoning might apply to fin and rudder... when does a rudder have enough authority to compensate for a violent unstart of an outboard engine...