Aircraft Accident Brief Ntsb/aab-02/01 (Pb2002-910401): Egypt Air Flight 990, Boeing 767-366er, Su-Gap - National Transportation Safety Board Page 150
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160 crew recovered the airplane because those were the flight characteristics when the FDR stopped
recording. Precisely what happened after Flight 990 recovered is unknown because both the
CVR and FDR stopped recording. It does appear, however, from the location and condition of
the left engine, that pieces of the airplane, including the left engine, departed the airplane prior to
the beginning of the second, fatal dive toward the ocean. The loss of the left engine -- likely due
to an overstress of the airplane during the ascent back to 24,000 feet -- created an asymmetrical
load on the airplane from which recovery was virtually impossible. Consequently, regardless of
the reason that the airplane initially departed cruise flight, there is a substantial argument that the
reason that Flight 990 crashed was because it lost a major component -- the left engine -- which
rendered the airplane unstable and unrecoverable.
26.
(Page 58) As a result of the EgyptAir’s January 12, 2001 response to the Boeing
submission, the NTSB was compelled to conduct further simulator tests and bench tests of the
pressure relief valves of the elevator control assembly. These additional tests were required
because of the incorrect data -- identified by EgyptAir -- that Boeing had submitted to the NTSB.
The inaccuracies in the Boeing submission resulted in incorrect blowdown data for the elevator
which was subsequently used as the basis for some of the airplane performance analysis. These
facts should be included in the report to document the inaccuracies of the Boeing performance
data relied upon by the NTSB. The variances in Boeing data demonstrate how easy it is to move
the FDR flight profile towards, or away from, the E Cab simulator profile for a dual actuator
failure. This aspect of the investigation underscores the manner in which the factual record and
the subsequent analysis was selectively developed in the draft report.
27.
(Page 59) The NTSB’s assertion that there was “no evidence of any ATC
problems or issues” is incorrect. The ATC transcript included in the docket shows that Flight
990 was “lost” in the ATC system during the handoff from New York TRACON to New York
ARTCC. Further, the controller did not attempt to contact Flight 990 until six minutes after the
accident sequence began and almost four minutes after the airplane crashed into the ocean. It
appears that the light early morning air traffic may have lulled the controller into a period of
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