Posted on 01/04/2004 2:32:44 AM PST by BenLurkin
That question has been answered for those with the ability to do a liitle of their own non-conspiratorial based reseach with the amount of material about this event on the web nowadays - your overlooking some of the more substantative excerpts I've posted above certainly gives me a clue where you're coming from, too; convincing folks such as yourself is an possible task, I'm convinced. All I can do is present the substantial, factual evidence by the competant folks and leave the reading to the readers ...
If you wish continually paint every catastrophic event that has occurred with a conspiratorial paint-brush - have at it. Just remember that technology's operation isn't based on black magic, every physical system has limits and sooner or later a failure can be expected to occur - usually though a combination of adverse circumstances ...
Yeah. Why don't we.
But let's look at specifics involving that 13 year old aircraft and it's 13 year old airframe bearing tail number N14053 (AA FLT 587 that day) -
- excerpted from: www.aviationtoday.com/reports/iceberg.htm
Hmmmm ... it seem to me that there's more than enough to look at with just this series of aircraft (the A300 Airbus series) as well as this particular aircraft for potential inherent deisign flaws or service issues (repair mistakes).
- A300-600R N14053's (AA Flt 587's) computer and flight control system: According to the NTSB, N14053's maintenance log revealed that during a preflight check on the morning of the accident, "the yaw damper and a pitch trim control would not engage ... The computer controlling these functions was reset."
- A300 rudder problems: Less than two weeks after AA587, another American A300-600R (tail No. N7055A) fishtailed after takeoff from Lima Peru. Similarly, on May 11, 1999, American A300-600R tail No. N7082A, a third aircraft in American's A300 fleet, during approach to Miami and go-around suffered 5-11 degrees of continuous erratic and uncommanded rudder deflection resulting in extreme yawing.
Maintenance personnel in Oklahoma had apparently cross-connected wiring from the flight control computers to the yaw actuator valves. (Implementation of a subsequent FAA Airworthiness Directive revealed another aircraft to have been cross-wired.)
Records reveal that earlier, in September 1996, another American Airlines A300 had just climbed to 31,000 feet when violent shaking began, accompanied by an uncommanded 5-6 Hz. rudder pedal movement that the flight crew could not override. The captain declared an emergency and landed.
Did AA587's flight data reflect similar uncommanded control issues that led to disaster? Given several instances of cross-wiring and issues with N14053's computerized yaw damper control, could the above instances indicate ongoing problems involving these items and possibly the rudder limiter?
Is there a maintainability challenge with such increasingly complex systems? And to what extent is computer/autopilot override by the pilot of Airbus aircraft more complex than it needs to be under high-stress emergency conditions?
- A300-600R N14053's (AA Flt 587's) vertical stabilizer: A folded ply had apparently allowed minor separation in the left center fin attachment lug during the manufacturing process more than 13 years earlier. Repaired before delivery with a number of rivets, it was found still firmly attached to the left central fuselage clevis even though the skin and fin structure above the lug had been entirely torn away.
Were there any equivalent undetected anomalies in the upper portion of the fin? Will the fin's skin and internal structure be completely disassembled to look for such anomalies?
- Previous A300-600R N14053 incidents: In November of 1994, an FAA Incident Data System Report records that this same aircraft encountered clear air turbulence whose severity caused injury to 47 passengers and damage to the aircraft.
This aircraft was 13 years old.
How many landing/takeoff cycles had it undergone, involving alternate cold-soak temperatures of -45 degrees Fahrenheit to -60° F at altitude followed by ground temperatures up to 95° F?
Were there other significant turbulence events [during it's lifetime]?
Given such stresses and alternating temperature/pressure changes over 13 years and 37,500 flight hours, what were the combined effects on rigidity, integrity, and fatigue-resistance of the composite vertical stabilizer?
And did extreme rudder movement at 300 mph apply significant torsion along the hingeline of a fin whose stiffness might have degraded, triggering the kind of dangerous aeroelastic divergence hypothesized above?
It should be noted that while Airbus documents indicate testing over thousands of cycles equivalent to almost three airframe lifetimes, there is no indication of load-bearing testing under the extreme range of temperatures (and pressure changes) involved in the multiple heat-soak/cold-soak cycles experienced in daily service (see ASW, Jan. 14).
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