@pattern
I'm not sure about this but I believe that the B52 didn't have any hydraulics in the vertical stabiliser - I'm sure someone here will correct me if I am wrong there.
When AA587 lost its fin it also lost all hydraulics since it was supplied by all three systems. Consequently there was no aerodynamic control of any sort available whereas, if I am right, the B52 at least had elevators and ailerons.