Tenth Update On NTSB Investigation Into Crash Of American
Airlines Flight 587
Transportation Safety Board has 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
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.
The team has completed its examination of the flight control
cable routing for possible failure modes that could have led to the
accident. The team has also examined the design of the A300-600
rudder limiter system and performed comparisons of other
The group has examined
issues related to the directional stability and control
characteristics of the Airbus A300-600, obtaining expert
information on pilot/aircraft coupling design issues, evaluating
aircraft response to differing rudder designs, and examining the
service history of the A300-600 for high tail load events that
might involve issues related to the accident.
The Safety Board currently expects to deliberate over a final
accident report in a public meeting in Washington, D.C. during the
Spring of 2004.