The National Transportation Safety Board today
released the following update on its investigation of the
November 12, 2001, crash of American Airlines flight 587, an
Airbus A300-600, in Belle Harbor, New York, which resulted
in the deaths of all 260 persons aboard and 5 persons on the
ground.
Composite Lug Test
On August 13, 2003, the NTSB conducted a lug sub-
component structural test at the Airbus test facility in
Hamburg, Germany. Engineers from the NTSB, Airbus, American
Airlines, BEA, and the NASA Langley Research Center
supported the testing and analysis.
The test component was a rear main attachment lug from
an A310-300 Carbon Fiber Reinforced Plastics (CFRP) fin box
skin panel. The panel was originally constructed as a
manufacturing quality test article and was used to
demonstrate the interior quality of the skin panel.
The test was to demonstrate the behavior of the lug
under a load condition similar to that experienced by
American Airlines 587 during the accident flight. The load
condition used was derived from the flight data recorder
information and the subsequent structural finite element
analyses.
During the test, the lug structurally failed at a load
beyond its design ultimate limit. The test failure appeared
to be consistent with calculated failure load analyses
performed by both Airbus and NASA Langley. Work is
continuing at the Safety Board to continue refining a
reliable estimate of the loads on the AA587 fin during the
accident.
The Safety Board has obtained two other lugs for
testing. Two rear lugs were removed from the tail fin from
the A-300-600 aircraft that was involved in a loss-of-
control incident in 1997 as American Airlines flight 903
(see Fifth Update, February 25, 2002). These lugs will
undergo structural tests in December of this year and
February 2004 in Hamburg.
www.ntsb.gov