LittleKeepings - so that's the final word, is it? A bit arrogant, perhaps?
Might you provide a pointer to Mr. Farley's wise remarks for those who would care to read it again without a long excavation journey through the archives?
The details of certification and testing - whether true to the issue or not - are but a small part of this complex situation.
Every fool who flies (or does the math) knows that one can harm the structure of an aircraft, large or small, by horsing it around enough to breach some structural limit.
What is so remarkable about the situation with the carbon-tail Airbus is that the margin of safety between normal flight operations and auto-destruct seems to have dwindled to nearly nothing - in the normal, everyday, best case, mind you - as a result of particular design, manufacturing, and control characteristics incorporated into the aircraft.
It is wildly disingenuous to argue that all the current information about the general strength limitations and doubtful long-term maintainability of the carbon fiber tail, the idiosyncracies of the yaw damper / rudder actuators, vagaries of the YD control logic, the high breakout thresholds at the rudder pedals and other as yet unpublic details about the flight controls were visible or widely understood by flight crews, training managers and regulatory officials prior to the crash of AA587.
I find it hard to believe that many (or any) people had previously evaluated those factors correctly in a context similar to the present case.
Some compromise with reality is appropriate in commercial aircraft design. Nobody is arguing for the repeal of gravity or aerodynamics. The issues here have meaning both for he pilots that fly 'em and folks that design 'em. The issues have to do with how the hard physical realities connect through fallible materials to human nature.
The 100-year evolution of aircraft has caused them to be fitted with progressively more sophisticated instrumentation that helps ordinary mortals (with ample flying skills) keep them right side up and pointed in the desired direction under the wildly variable circumstances of commercial aviation. Passenger aircraft have a panopoly of systems that work to increase the safety and health of the passengers and crew. High among these are monitors and indicators that show critical data such as whether the wheels are up, down, or somewhere inbetween, lights and screens that show what is on fire at a given moment, and guidance for a myriad of management details ranging from COFFEE OVERTEMP to GROUND PROXIMITY.
AA587 points to an apparent propensity for the Airbus tail to depart the aircraft during easily initiated and fairly unremarkable manoeuvering.
If tail breaking off is such a readily accessible risk, then surely some effective operational warnings would be appropriate. The fact that warning mechanisms are not part of the A300 design proves that the high risk of engaging this catastrophic failure mode in normal flight conditions was not 'common knowledge', as some argue.
If the situation is really one that a skilled pilot can stumble into on a clear day while launching a flight in a 'perfect' aircraft, then probably the Airbus flight crews need better real-time information about where the aircraft is in the envelope, and maybe also an extra interlock or two to help keep them on the warm side of eternity.
Rather than taking the CYA position that the crew should have known intuitively what was happening 40 meters behind them in those few critical seconds, would it not maybe make sense to talk about adding some better information for the guys up front? Perhaps a little indicator that pulls together the already available information about the flight envelope and says in red: "TAIL CRITICAL".
Sadly we cannot rewind the clock. The noise here is about is how to make sure this never happens again. Right?
Last edited by arcniz; 20th Nov 2002 at 08:25.