November 4, 2003 - by Victor
Trombettas
As we approach the 2nd anniversary of the 2nd worst aviation crash
in U.S. history, U.S.Read and the dozens of experts who have contributed
to our Flight 587 coverage extend our heartfelt sympathy to the
families of the victims. U.S.Read also feels a sense of
sorrow because we are convinced the truth of Flight 587 will never
be revealed. We have lost faith in the NTSB and any possible
Governmental oversight. The one arena we felt might still
hold some hope for the unveiling of this mystery -- the lawsuits
by the families -- will also fail to deliver the most precious
settlement -- the truth. U.S.Read does not believe that
the tail departing the aircraft was the cause of the crash.
Tail departure was no more the cause than the engine separations
were. Both tail and engine departures were a consequence
of some catastrophic event which led to a loss of control of the
aircraft and the subsequent in-flight breakup.
The day of the crash, Chairman Blakey's comment that "all
indications are that this is an accident" clearly showed
the U.S. Government's bias. We believe that this bias, this
rush to judgment, guided the NTSB down the wrong investigative
path that saw them ignore the witnesses and at times discredit
them. They have also misinterpreted the flight recorders and most
of the other evidence. This will all culminate in a probable
cause that will not accurately represent what happened that awful
morning two years ago.
In the year since the Hearings and the release of the factual
reports, U.S.Read's experts have seen many indicators of a flawed
investigation. Quite frankly, we are overwhelmed by it and do
not know where to begin in our coverage. Perhaps the first
thing we can say about the official investigation is that if we
accept what the NTSB is telling us, then we have more reason than
ever to believe that today's jetliners are terribly unsafe and
the NTSB and FAA have done nothing to change that.
What They Believe
Picture
1 at 9:15:53.2 - Load Limits Exceeded
Picture 1 shows Flight 587 at 9:15:53.2 (approximately
5.3 seconds before the NTSB believes the tail departed).
At this moment the aircraft was in only a 5 degree nose-right
sideslip (the nose was to the right of the direction of flight)
and the rudder was deflected to the left 11 degrees (the 2nd of
5 rudder movements -- a.k.a, the first "reversal" of
the rudder). It is important to note that in the 3 pictures
that follow, the aircraft is never in what the industry calls
an "upset". The blue and brown colored circular
ball is the artificial horizon indicator which shows bank (roll)
angle and the position of the nose with respect to the horizon
(pitch). For example, in Picture 1, the aircraft is in a 9 degree
climb and has a 10 degree left bank. The NTSB states the
FAA's tail limit loads (as defined by the FAA certification requirement)
were slightly exceeded at this moment. Simply by depressing
the rudder pedal just a couple of inches in both directions in
less than 2 seconds, the pilot has placed loads on the tail beyond
those the FAA felt should ever be experienced in service.
Picture 2 at 9:15:56.8 - Ultimate
Load Exceeded
Picture 2 shows the aircraft at 9:15:56.8 with a 7 degree nose-right
sideslip and the rudder deflected 10.2 degrees left (the aircraft
is almost completely level -- no noticeable pitch or roll angles).
We are told that now the tail's "ultimate load" has
been slightly exceeded. The "ultimate load" is
the limit load multiplied by a safety factor of 1.5. The
tail must survive this load factor for 3 seconds according to
the FAA requirement.
Picture 3 at 9:15:58.5 - Limit
Load exceeded by factor of 1.9 times
Lastly, Picture 3 shows the aircraft at 9:15:58.5 (when the NTSB
believes the tail departed) with a 10 degree nose-left sideslip
and the rudder deflected 11.5 degrees right (the nose is pitched
down only 3 degrees and there is an 8 degree bank to the right).
At this instant, the tail is suffering a load 1.9 times the limit
load and has performed as well as even a new tail could be expected
to perform. Just look at the aircraft in Picture 3 and understand
that the NTSB is telling us that (a) In this type of attitude
(this is still not an
upset by industry standards) the pilot had better not apply any
rudder in the opposite direction of the sideslip (or yaw), and
(b) the imposed stress on the tail is way beyond what it was ever
designed to endure.
What if an aircraft gets
into a sideslip because one engine has quit at some speed above
270 knots? How much rudder can a pilot use to compensate
for the sideslip that will ensue without exceeding load limits?
Half the available distance? That would mean the pilot could
only move his foot about a half inch (depending on the aircraft
model) -- since a little more than an inch would throw the rudder
to its full travel distance. Worse yet -- what if an unintended
sideslip ensues and the aircraft suffers an uncommanded rudder
movement to the opposite side? Then what? Flight 587
supposedly went from zero load on the tail (during the last rudder
movement in Picture 3) to beyond ultimate load in only four tenths
of a second. By no means enough time for a pilot to somehow
respond and prevent a catastrophe from occurring if the rudder
moves on its own.
We Do Not Believe
Of course, history tells us that this just can't be true.
If tails were really constructed with such low tolerances for
stress, surely, more tails would have fallen from jetliners long
before Flight 587. But what matters here is that the NTSB
believes this. Both the NTSB and the FAA have done nothing
about this very disturbing situation except to tell the airlines
to make the pilots aware of this new understanding, and warn pilots
not to reverse the rudder. U.S.Read's position is, as members
of the flying public, that if the NTSB and FAA really believe
this, then increasing the certification requirement appears to
be an absolute necessity. This has not been done. We see
no indications that anything sensible will be done. All
they have done is put the pressure on pilots to be aware of how
sensitive the rudder system is and how easily a tail can break
off.
Ultimately, U.S.Read does not believe that tail separation was
the cause of the crash. The very evidence the NTSB has presented
to establish the load calculations and rudder movements mentioned
above are unsupported by the Flight Data Recorder. That is just
the tip of the iceberg. The evidence does suggest that at the
time of Picture 3, something catastrophic had already occurred
to Flight 587. The tail very likely was still attached beyond
this point and departed up to 8 seconds later. If the flight
data recorder, the cockpit voice recorder, the radar data, the
tollbooth video, the debris field, the Air Traffic Control tapes,
the eyewitnesses, were all correctly interpreted, without the
NTSB's bias, the initiating event before the assumed tail separation
point would be clearly identified. U.S.Read hopes to cover
all this in more detail in upcoming articles.
Our warmest thoughts and prayers are with the families.
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at airdisaster.com