Teledor(lessthan)serious
Must be fun to get an Airbus type...
Have you even read the Boeing contributions on this problem? you can find them here:
http://www.ifalpa.org/downloads/Leve...20aircraft.pdf
I would draw your attention to this extract:
The FAA/EASA have three rudder manoeuvre structural load design requirements, which the rudder and vertical fin must
meet in order to be certified3. These requirements are met for all airspeeds up to the design manoeuvring speed. In addition, newer
aircraft designs meet these requirements up to the design dive speed.
At a zero sideslip condition; the aircraft must be able to withstand a rapid rudder input to full rudder deflection. A Safety
Factor of 1.5 is then applied. This means the structure must have at least a 50% safety margin over the maximum load
generated by this manoeuvre.
Starting from a zero sideslip condition, the aircraft must be able to withstand a rapid rudder input to full deflection that is
held at full deflection until the maximum sideslip angle (over yaw) is achieved. The aircraft will exceed the maximum
steady state sideslip due to the dynamic response characteristics of the aircraft. A Safety Factor of 1.5 is then applied.
Starting from a maximum steady heading sideslip condition, the rudder is rapidly returned to neutral while maintaining
the sideslip angle. A Safety Factor of 1.5 is then applied.
During certification, Boeing does not flight test these exact conditions, but gathers flight test data to validate structural loads analysis.
This analysis, combined with ground structural load testing, ensures that the structure meets design requirements.
The FAA/EASA impose structural load design requirements in addition to these rudder manoeuvre requirements. These include
requirements for loads due to gusts, engine failure dynamics, and lateral control induced rolling conditions. Boeing aircraft vertical
fins can also sustain loads if the rudder is rapidly returned to neutral from the over yaw sideslip or the rudder is fully reversed from
a full steady state sideslip.
Note 3: These conditions are engineering design conditions that may be physically impossible to fly.
Also to Fig.3 which shows the sideslip response to cyclic rudder movements and Fig.4 that shows the torque on the vertical stabiliser due to cyclic application of rudder.
Now you may think it amusing to slag off Airbus with cheap shots, but there are folks on this forum that actually take things more seriously than that. Let me remind you that the extract quoted above comes from Boeing. Note the careful wording that their vertical fins can sustain loads if the rudder is rapidly returned from over yaw sideslip or the rudder is fully reversed from a full steady state sideslip. No mention of the fin being able to carry the torque if the rudder is fully reversed at peak over swing sideslip. And all that relates to a single application and reverse of rudder. Look at the effect of cyclic rudder application on sideslip and you will (or should be able to) see that applying full reverse rudder at a peak of an enhanced overswing sidslip is going to produce loads well in excess of the structural capability. And that is for a Boeing aircraft!
In their equivalent document Airbus do not specifically mention an ability to withstand loads if the rudder is rapidly returned to neutral from the over yaw sideslip or the rudder is fully reversed from a full steady state sideslip, but the fact that the AA587 fin failed at about 2.2 times the limit load (as against the statutory 1.5 times) shows that their design has similar structural reserves to Boeing. [And that was the fin with the factory repair that you suggest might have been faulty - don't you realise that any aircraft repair has to be designed to be at least as strong as the original structure!]
I can only concur with Air Rabbit that you might benefit from some serious study of aircraft design and construction.
BTW, you did not respond to my request for identification of the source of your original remark re FAA changes to Va. There was a long debate about the definition of Va in an earlier thread. Perhaps you should also read Keith William's contribution in #21 of the Va Manoeuvring thread