Posted on 12/19/2001 7:23:07 AM PST by Incorrigible
12/19/01
BY TED SHERMAN
STAR-LEDGER STAFF
[New York, NY] -- The tail control surfaces of the doomed American Airlines Airbus A300 that crashed in New York last month malfunctioned during a routine preflight check, investigators revealed yesterday.
While they said the problem apparently had been resolved by resetting a computer, a similar American Airlines Airbus was grounded in Lima, Peru, earlier this month after pilots reported the plane had begun "fishtailing" shortly after takeoff.
Meanwhile, the European manufacturer of the passenger jet is refurbishing a simulator to examine possible malfunction scenarios within the rudder system of the aircraft, according to the National Transportation Safety Board, which is heading the investigation into the Nov. 12 crash of Flight 587.
WAKE TURBULENCE
The American Airlines Airbus bound for the Dominican Republic went out of control just minutes after takeoff from John F. Kennedy International Airport, as it flew in the turbulent wake of a much larger Boeing 747 jumbo jet.
Much attention has been focused on the tail and vertical fin of the jet -- made of light-weight, carbon-reinforced plastic composite panels. The recovered wreckage shows the fin separated cleanly from the fuselage as if cut by a knife, just before the plane spiraled down, killing all 260 passengers and crew. Five people on the ground also were killed.
The Airbus made wide use of composite structures throughout its airframe -- materials widely used in military aircraft but only recently being used to replace metal and alloys in commercial jets. Since the accident, U.S. and French aviation authorities called for the visual inspection of every Airbus A300 in operation, amid growing concerns of a major design flaw.
To date, no inspection has turned up anything unusual, but United Airlines -- which employs a more rigorous ultrasound inspection of its Airbus fleet -- said last week it discovered a tiny flaw in the vertical fin of an Airbus A320's tail section. The airline found a small separation in the carbon fiber, but believed the problem was "insignificant," and returned the plane to service without repair.
The rudder controls of Flight 587 also have loomed large in the investigation. According to the black box data from the plane, the rudder made five large swings just after it passed through the wake vortex of the 747, and before the aircraft began to break up. According to the NTSB, a review of Flight 587's maintenance log shows that on the morning of the accident, a pitch trim control and the yaw damper would not engage during a pre-flight check.
The yaw damper moves the rudder in small increments to keep the plane stable so it flies straight ahead. The pitch trim control helps move the plane up or down.
The maintenance log showed that the computer controlling those components was reset by a mechanic, which resolved the problem, and NTSB investigators found there were no other maintenance items noted regarding the vertical stabilizer or rudder system when the aircraft took off.
After the incident in Lima this month, mechanics there replaced the aircraft's yaw damper actuator.
SAVING THE PIECES
Most of the wreckage of Flight 587 is now in containers at a storage facility in Harrison, N.J. The tail section was delivered to NASA's Langley Research Center in Hampton, Va., the week of Dec. 3 and is undergoing nondestructive inspection -- including ultrasound, tap-testing and photography using heat-sensitive film.
The NTSB also is looking into the aircraft's auxiliary power unit, a small jet engine used to provide power for aircraft systems while on the ground and also for emergency electrical backup during flight. The unit is located in the tail of the aircraft and tests are being conducted to determine how much of its heat may be directed onto the vertical stabilizer.
"We're trying to come up with the right testing protocols," NTSB spokesman Ted Lopatkiewicz said of the ongoing investigation. "At this point we're eager to see what we can learn from those tests."
Not for commercial use. For educational and discussion purposes only.
Others may disagree.
Fore more articles on Flight 587 click *AA Flight 587 or AA Flight 587
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What rock have you been living under? According to NTSB the pilot suicidally deliberately crashed the plane. This has been stated publicly, and well before 9/11. Only people in denial are the Egyptians. There's no "Mystery" at all.
Meeting the deadline was impossible from day one. You can't screen luggage for bombs with machinery that hasn't been manufactured, can you?
Don't you just hate those pesky little details? *smile*
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