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  • worksntv@aol.com
    ... From: NTSB Press Releases Reply-To: Date: Tue, 15 Jan 2002 13:33:31 -0500 NTSB Advisory National
    Message 1 of 1 , Jan 16, 2002
      ---------- Original Message ----------------------------------
      From: NTSB Press Releases <NTSBPressReleases@...>
      Date: Tue, 15 Jan 2002 13:33:31 -0500

      NTSB Advisory
      National Transportation Safety Board
      Washington, DC 20594

      January 15, 2002


      The National Transportation Safety Board today released the
      following updated information on its investigation of the November 12 crash
      of American Airlines flight 587 in Belle Harbor, New York, which resulted in
      the deaths of all 260 persons aboard and 5 persons on the ground.

      Vertical Stabilizer and Rudder

      The aircraft's tail section has been in NASA's Langley Research
      Center in Hampton, Virginia since early December. In the intervening weeks,
      the Safety Board has conducted a series of non-destructive tests to
      determine whether the vertical stabilizer and rudder had any pre-existing
      flaws before the accident. Some delamination has been noted, but at this
      time it is not known whether this occurred before impact or as a result of

      Contrary to recent press accounts, the Board has not ruled out
      either mechanical malfunction or structural defect as causing or
      contributing to the accident. Work at NASA Langley will take many more
      months and will transition to more extensive and intrusive tests of the
      stabilizer and rudder.

      Although the flight data recorder showed significant rudder movement
      during the last moments of flight 587, it is not known what caused the
      movement - whether it was mechanically induced or pilot activated - or what
      role, if any, the movement played in the separation of the vertical

      The Safety Board is surveying salvage yards for an intact A300-600
      vertical stabilizer and rudder as an exemplar for potential tear down and
      examination. The undamaged exemplar could be helpful to investigators as
      they examine the accident airplane's composite materials and attachment


      In the course of the NTSB's continuing investigation, over 350
      eyewitnesses to some segment of the accident sequence have been identified.
      Those who have not already provided written statements or been interviewed
      by NTSB personnel will be contacted shortly. Some of these individuals
      mentioned observing fire or smoke before the plane impacted the ground,
      although the majority of them do not. Although at this time no physical
      evidence of an inflight explosion or fire has been discovered, the Board is
      taking into full consideration the observations of all witnesses. Witness
      statements will be made part of the public docket of this investigation.

      As previously announced, the Safety Board has established a web site
      (AA587wit@...) for eyewitness statements. All persons who can provide
      eyewitness testimony about this accident who have not yet been in contact
      with Safety Board personnel should contact the NTSB through this site.

      Flight Data Recorder

      The flight data recorder continues to be analyzed. That process is
      taking a little longer in this case because signals for some parameters on
      this aircraft are "filtered" before they reach the flight recorder. The
      filtering operation is used to smooth data that drive cockpit displays so
      that the needle (or other indicator) does not jump around. This filtering
      is accomplished by averaging the data over time. When large, rapid
      movements are made, this averaging will distort the recorded data; rapid,
      extreme control movements are clipped off. As a result, the readings on the
      recorder show what the gauges were telling the pilots, not necessarily what
      was actually occurring on a real-time basis to the aircraft. This will
      require some aircraft testing and then further computations by Board staff
      to get the true readings on some parameters of interest like rudder,
      elevator, and aileron movement. Although this has added to the workload of
      investigators, it is not expected to affect the quality or the timing of the
      Board's final product.

      In 1994, the Safety Board recommended to the FAA that such filtering
      systems be removed from information sent to flight data recorders. The FAA
      told the NTSB that its 1997 final rule amending FDR requirements "precludes
      the use of a filter and specifies the seconds-per-sampling interval for all
      parameters." Based on that information, the Safety Board closed its
      recommendation as "Acceptable Action" on August 9, 2000. The Safety Board
      has alerted Airbus and the FAA of the problem noted on the recorder
      recovered from American Airlines flight 587.

      - 30 -

      NTSB Press Contact: Ted Lopatkiewicz
      (202) 314-6100

      This message is delivered to you as a free service from the National
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      releases is available at http://www.ntsb.gov/pressrel/pressrel.htm.

      For questions/problems, contact donaldl@...

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