Ptkay, the accident has nothing to do with Va, please read the entire thread.
The accident was caused by the pilot trying to use the rudder to assist the roll of the aircraft during a wake encounter. He did not intend to use full rudder, but a strongly suspected design flaw in the rudder control system, caused the pilot to apply full rudder deflection when he did not intend to.
Again please read the entire thread, and the other thread regarding this accident.