Mechanical Failure
The possibility of mechanical failure as a pertinent factor
in the crash of EgyptAir Flight 990 did not require prompting by Egyptian
officials or news media to arise. In the three year period prior to the incident,
EgyptAir 990 was the third Boeing jet to experience a fatal crash after taking
off from New York's JFK Airport on what would have been a transatlantic flight
(TWA 800 and SwissAir
111). This fact alone was enough to prompt concern.
Soon after the crash, different sources began to ask questions.
As mentioned in the previous section, three weeks after the
crash the Austrian Institute of Aerospace Medicine and Space Biology theorized
that a "flight stabilizer breakdown" could have caused the Boeing
767 aircraft to disengage the autopilot and begin its fatal decent. This story,
which ran in the Washington Post ("Austrians offer malfunction theory
of EgyptAir crash") and was referenced in Egyptian and Muslim press to
give credence to a mechanical failure theory, did not last long. Once more
flight data became available to the NTSB investigators, the stabilizer runaway
scenario did not conform with the evidence(1)(2).
Salvaged wreckage of Flight 990
Boeing in the spot light.
In a case of bad timing for Boeing, several stories developed
around the same time as the crash which helped to encourage pursuance of theories
like the one above. For instance, just two days before EgyptAir's crash, NTSB
officials announced that "Boeing had concealed from NTSB officials investigating
the TWA Flight 800 crash a report which shows that the aircraft manufacturer
was well aware of the dangers of a fuel tank explosion in its 747 jets."
NTSB and FBI investigators battled for a year and a half over the proposed
causes of the crash of TWA 800. The FBI (and Boeing) focused on terrorism
as the culprit while the NTSB eventually settled on a fuel tank explosion
in the left wing. If the report, which was produced in 1980, had been given
to investigators, they would have instantly focused on the fuel tank explosion
as a possible scenario. (3)
Then, less than a month after the incident with EgyptAir, the
FAA "ordered a special inspection of Boeing Co. after a series of quality-control
problems, including the discovery by American Airlines mechanics of 16 improperly
tightened bolts in a Boeing 767 tail section" (Washington Post, "FAA
Calls A Special Inspection Of Boeing" Nov. 26, 1999) (1)
The results
of the investigation were announced a year later and most likely did not
have any direct bearing on EgyptAir 990, but the timing of the investigation
in relation to the crash did nothing to improve Boeing's image.
As must be considered, and was stated in articles by the World
Socialist Web Site:
Boeing Corporation would have a vested interest in the discovery
of a startling piece of evidence on the cockpit tape that obviated the need
for a protracted examination of the wreckage. A prolonged probe, whatever
the ultimate findings, would raise doubts about the safety of the 767 aircraft,
with potentially damaging, if not disastrous, consequences for the company's
profits and financial stability. (4)
This suspicion was enhanced by the NTSB's abrupt change in
focus from a mechanical problem to a pilot suicide theory. On Monday, November
16, the NTSB along with officials from Boeing and representatives of the company
that makes the plane's engines, Pratt & Whitney, comprised a "cockpit
recorder group" that proceeded to analyze the cockpit voice recording:
Reports leaked to the press said the initial reading of the
tape did not indicate that the pilots fought with each other, that any of
the crew attempted to commit suicide, or that someone entered the cockpit
and caused the crash. But as the Washington Post reported on Tuesday, November
17: "The tone of the investigation changed overnight. A day ago, the FBI
was saying with certainty that no evidence of criminal acts had been found.
And numerous federal law enforcement and political sources, who Sunday night
said a preliminary reading of the Boeing 767's voice recorder contained
no indication that the plane was deliberately crashed by someone in the
cockpit, are now not so sure."(4)
Barry Grey, the author of the wsws.org article further speculates
that the catalyst for this sudden shift in scrutiny is the discovery of the
Islamic prayer supposedly repeated by the relief co-pilot, Gamil al-Batouti.
He claims further that this is evidence of the FBI attempting to get mechanical
failure out of the picture and gain control of the investigation. (4)
Another unsettling anomaly involving Boeing is the fact that
the EgyptAir 767 that crashed "came off the assembly line at the Everett,
Washington plant in the fall of 1989 just before another 767, built for the
Austrian airline Lauda, which crashed in 1991 in Thailand." The Lauda
jet crashed because of a mechanical malfunction in which the reverse thrusters
deployed in mid-flight. The reverse thruster scenario was suggested in the
first few days of the EgyptAir incident, but was discounted rather quickly.
However:
The Everett plant was working such heavy overtime during
1989 that it produced widespread complaints from rank-and-file machinists,
ultimately sparking a 48-day strike which began October 4, 1989. The Egyptair
jet was delivered September 26, 1989, the 282nd to be built, and the Lauda
jet followed on October 16, 1989, the 283rd, with work completed by nonunion
personnel after the strike began. (3)
In all probability, these coincidences are just that, coincidences,
but in an important and complex investigation such as an unexplained plane
crash, all the various factors and components need to be considered.
As was stated previously, due to the fact that Egypt is an
important customer of the Boeing Company, representatives of EgyptAir as well
as Egyptian government officials downplayed the possibility of mechanical
failure in the beginning. Not only did Egypt's president, Mubarak insist on
Boeing's integrity, but Captain Abdel-Fattah Orabi, who piloted the doomed
craft on its first leg from L.A. to New York, also defended the company's
reputation. The Egyptian paper, Al-Ahram Weekly, stated "another reason
why the chief pilot insists the plane did not suffer a technical problem is
because 'Boeing is a highly respected manufacturer and its reputation is in
a class of its own in comparison to other plane-makers.'" He continued to
explain that the 767 has been designed to handle a plethora of emergency scenarios,
and in all but the most extreme, can either safely recover or safely land.
(5) It should
be noted, however, that at this time, Egypt was still attempting to push the
idea of a missile or bomb as the most likely determinant for EgyptAir's destruction.
Once this hypothesis was officially ruled out, Egypt had no choice but to
investigate the potential for a mechanical failure.
As with any airplane crash investigation in which the participants
are attempting to recreate plausible scenarios based on inconclusive data,
the investigation of EgyptAir 990 was incredibly complex.
The tug-of-war that ensued over issues of mechanical failure
are extremely detailed and technical. For a complete understanding, one should
read the following sections of the NTSB
report: Bellcrank Anomalies (pgs. 12-13), Wreckage Information (pgs. 18-19),
Potential Causes for Elevator Movements During the Accident Sequence (pgs.
22-27), Additional Information/Submissions (presents EgyptAir's challenges
to the technical data regarding mechanical malfunction, pgs. 27-31) and Analysis-General/Mechanical
Failure/Anomaly Scenarios (pgs. 31-37).
After Egypt had turned over the investigation to the U.S.,
EgyptAir sent a team of pilot/investigators and engineers to Washington to
"assist" with the proceedings. Their research uncovered potential
scenarios, based on previous malfunctions of 767s, that could have occurred
in the case of EgyptAir. As William Langewiesche, a pilot and participant
in the study, describes in his article, The
Crash of EgyptAir 990, the elevators on a 767 are controlled by "three
redundant hydraulic circuits, driving a total of six control mechanisms called
'actuators,' which normally operate in unison." The Egyptian team discovered
"that if two of the six actuators were to fail on the same side of the
airplane, they would drive both elevators down, forcing the 767 to pitch into
a dive that might match the profile that had emerged from EgyptAir 990's flight-data
recorder." If this dual malfunction were to occur, corrective measures
taken by either pilot could result in the split elevator scenario that resulted
during Flight 990's recovery attempt. The NTSB had recovered 4 of the 6 actuators
and did not find any signs of failure, but they requested Boeing look into
the matter anyway. (7)
Boeing engineers calculated that a dual actuator failure
would not have deflected the elevators far enough down to equal the known
elevator deflections of Flight 990, and that such a failure therefore would
not have caused as steep a dive. . . After adjusting the measured effects
for the theoretical aerodynamic pressures of flight, they found-as they
had expected-poor correlation with the known record of Flight 990 elevator
positions. They believed in any case that either pilot could quickly have
recovered from a dual actuator failure by doing what comes naturally at
such moments-pulling back hard on the controls. (7)
[see also: Potential Causes for Elevator Movements During the Accident Sequence
(pgs. 22-27) and Mechanical Failure/Anomaly Scenarios (pgs. 33-37) in the
NTSB Report]
The Egyptians then requested that Boeing perform expensive
new wind tunnel research since Flight 990's speed during its dive was up to
0.99 Mach and Boeing had used the available research for their study which
was for the 777 model aircraft and only went up to 0.96 Mach. (6)
(NTSB Report Note #78) As Langewieshe postulates, Boeing acquiesced "because
Egypt kept buying expensive airplanes and was influential in the Arab world."
Boeing then went on to studying crash scenarios in their high-tech 767 simulator.
First, they ran simulations based on the FDR data and had Langewieshe and
other pilots work through the actual motions of the failed flight. In addition,
Langewieshe and another test pilot were able to split the elevators of a 767
on the ground by applying the 50 lbs. of force necessary to break the elevator
torque tube and shear the bellcrank rivets, in a manner that the NTSB claimed
had happened on Flight 990. Next, Boeing had the pilots run through simulations
of the dual actuator failures that EgyptAir was proposing could have happened
to 990. In all cases, the pilots were able to recover from the dive with little
difficulty. The engineers even made the test pilots self-impose delays of
up to fifteen seconds. Langewieshe says that even after he waited fifteen
seconds before attempting a recovery, he lost 12,000 feet but was still able
to return to normal flying afterwards. (7)(6)
Having lost the battle over a mechanical failure scenario,
EgyptAir and conspiracy theorists could only turn to a selective interpretation
of the cockpit voice recording. Once the CVR and FDR data were synchronized,
however, viewing Batouti's actions as a response to an emergency became extremely
difficult.
Sources:
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2003 Jacob Lunow. All rights revered, all wrongs
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