AA587 Accident at JFK:
Forget the rudder.! We are talking about a larger and more
effective flight control surface in the vertical stabilizer.! This
extensive surface area of the fin and rudder, when struck by the
force of the rotating vortices, BROADSIDE, first on one side and
then the other, creates a tremendous shear force at the joint
structure.
At some point in time the 0.3, 0.4, and the 0.8 G forces break
the rudder control linkages to the rudder actuators. The free
floating rudder now moves with the directional changes in wind
shear forces and indicates the forces applied on the tail fin.
The designers, due to the requirement for control in engine out
on take-off, have now come up with a very sensitive weather
vane.! The 0.8 G force against the large fin will induce an
abrupt yaw motion, creating an instantaneous Dutch roll into a
steep left bank and a -30 degree dive attitude. There is no
evidence the pilot had use of right rudder to assist in any
recovery attempt, although he used full right aileron application
to counter the left bank.