Quote:
Now I'm a bit confused...
The Boeing guy says don't use rudders unless XYZ which excludes countering turbulence at low level..and I would assume Airbus' advice is similar... so based on that the handling pilots' actions were ill advised at best...
And the Airbus apparently had known defects which would have caused the failure and should have prevented it from being operated commercially initially...
Does anyonelese think that somewhere along the line somebody allowed a plane with a known flaw to be operated in a manner inconsistent with the advice of reputable aircraft builders...
Now I know its not as simple as that but it really does beg the question...if the weaknesses were known and the flying techniques were also known (Im' making an assumption here that the advice from Airbus re rudder operations is not dissimilar to that from Boeing...) how did this airline manage to train its pilots to operate such an aircraft in such a manner? Its almost as if the knowledge from one source was not combined with the knowledge for another in order to create the full picture....very curious.
|
I may be wrong on this (I don't think so, however), but I do not believe that Airbus ever cautioned any operator against rapidly deflecting the rudder to full deflection in one direction followed by full deflection in the opposite direction in the A-300. As some or all of you may know, the A-300 is not a FBW aircraft, so the flight and upset recovery techniques used in the later Airbus FBW aircraft (A-318, 319, 320, 321, 330, 340, 380) would not apply to it. The admonition against this type of rapid, cyclic rudder deflection only came to light
after the accident, when Airbus asserted that certification standards did not require the aircraft to be able to withstand this sort of action. Interestingly enough to me, I believe that the authorities had to conclude that Airbus was, in fact, correct with their assertion.
Up until the accident, I had never heard of this type of failure mode in a certified aircraft that was flying below Va. I know of no pilot that knew of this type of weakness in an aircraft. Pilots have always been taught (yes, even "Flying" Magazine's J. Mac McClellan) that flight at or below Va in any aircraft would prevent structural failure. The airplane would simply not be able to generate the aerodynamic force necessary to cause damage before an aerodynamic "stall" would occur. Flight through severe or worse turbulence, of course, would alter that rule a bit, due to the very rapid and uncontrollable changes in airspeed possible in this type of turbulence.
At my airline, airspeed limits have always been given in the "limitations" section of our Aircraft Operators Manual (AOM), along with the admonishment not to use full control deflections above the Va speed. That was it. Now, however, our manual states (as does every operator's, I believe) additionally that full and rapid rudder deflections, first in one direction, and then the other are to be avoided at all speeds, even those well below Va due to the possibility of structural failure.
As far as I know, this is not something anyone at AA (or any operator of the A-300) knew about before the accident. I believe this is something everyone discovered afterward - that no aircraft is technically required to be able to withstand this kind of back and forth rapid deflection of the rudder.
This is what I am aware of, btw. I do not claim to be the expert here. I am simply someone who is a pilot in this industry with a genuine professional interest in it (for 15+ years).