Originally Posted by Carl Spackler

You are correct. Nobody disagrees that a vertical stabilizer adds to stability. Stability is different than control. There is simply no aerodynamic facts to back up the premise that you lose control and crash if you lose the vertical stabilizer. None.

You talked previously about Dutch Roll. In the old 727 days, we trained in recovery from severe Dutch Roll with the Yaw Damper inoperative. The recovery technique involves the use of aileron only - you never want to touch the rudder.

Carl