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Our understanding is that below maneuvering you should not have failure due to control movement. That is not to say that you couldn’t get yourself into another area that would have consequences.
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The equation for maneuvering speed according to the book "Aerodynamics for Naval Aviators" on page 339.
is Vp = Va (square root) n-limit
Vp = maneuver speed
Va= stall speed
n-limit= limit load factor
another way to find it would be the point were a the stall line crosses above the load limit factor in a Vn diagram. also there is a safety factor added in because a gust load may be encountered why at this speed.
So the Va is biased on load factor.
"The flight load factor is defined by the proportion between airplane lift and weight where:
n= L/W
n=load factor
L=lift, lbs
W= weight, lbs"
so 10,000lb aircraft with 20,000lbs of lift would be 2 "G's" or a load factor of 2.
you cant change weight on the fly... but how you increase lift is increasing the airfoils Angle of Attack. And how you do that is with the elevator.
Va is only a number that involves exceeding the limits in pitch. Not rudder... so as i understand the AA flight didn't exceed the limits in pitch.. and was below Va... but still over "G'ed" the structural limit of the vertical stabilizer by swinging the rudder back and forth violently a few times.
You may never be able to exceed the structural limits of any of your controls on a fighter aircraft below Va but on other aircraft... such as a really big transport category aircraft...... the speed of Va is only a guideline for pitch and is not guaranteeing ANY limits of any OTHER control surface..
I'm not trying to be a jerk here...or to beat you up over this or anything... but this is something that could kill you and anyone flying with you. Anything beyond this explanation is is starting to get over my head and i would be happy to refer you to someone who could talk to you on a more technical level or who is carrying more credentials then i have so far obtained..
-Nick