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U.S.Read's Flight 587
Part 5: The Radar Data
October 13, 2004
Brett Hoffstadt and Victor Trombettas
In this part of our preliminary report we present the radar data which
indicate that the tail and engine separations on Flight 587 (FL587)
occurred later than established by the NTSB's timeline. This
would mean, among other things, that the crew lost control of the
departed. Therefore, the NTSB has not
identified the real cause of the loss of control –– nor have they
identified the initiating event.
The primary radar data from JFK airport showed the following (other key
events in the timeline are added for reference):
several seconds of aggressive control inputs and three calls for
maximum power by the pilot, the "loud bang" is heard on the Cockpit
Voice Recorder (CVR). The NTSB assumes the tail has just
separated with the rudder breaking up into at least 12 pieces. The
aircraft is now 0.82 NM (nautical miles) north of the crash site and
traveling southerly at an altitude of 2,535 feet (see Figure 1).
9:16:01.20 a.m.: All
Digital Flight Data Recorder
(DFDR) data abruptly ends yet the DFDR is still powered for several
beyond this point. The aircraft is at an altitude of
Why has the DFDR lost the entire data
stream? One possible explanation is that an onboard
fire/explosion has taken out the main data line that runs under the
cabin floor on the right side of the aircraft. The NTSB has stated on
more than one occasion that the engines (which power the DFDR) had both
separated by this time and that was the reason for the loss of all
data. But in late 2002, the NTSB revealed that the DFDR was
point where it lost the data stream. They
have yet to explain how and why the data stream was completely lost ––
13 seconds before impact and before the aircraft had even begun its
descent. This is one of the more substantial clues that suggests
a significant event on board created electrical disturbances, and could
well explain the pilot's loss of rudder control and the
failure of the wing spoilers.
U.S.Read is in complete agreement with
the NTSB that FL587 is out of control at this time. Pilot Sten
Molin even tells us that himself –– as we hear him say in a stressed
Control", on the Air Traffic Control (ATC), Local Control
At this point in the timeline (and at this point over Jamaica Bay), if
the NTSB's conclusions about how and when the aircraft broke apart are
correct, we should have multiple pieces of aircraft debris that appear
on the JFK radar in the range of 0.60 to 0.82 NM (nautical miles) north
of the crash site. The tail and rudder debris should be closer to
0.82 NM, and there should be some evidence of both engine separations
near 0.60 NM.
What the JFK radar data shows
piece of debris, 0.68 NM north of the crash site, is seen on the JFK
radar data. The aircraft itself is now 0.58 NM north of the crash site
(Figure 2) at an altitude of 2,398 feet.
According to the NTSB's timeline, we would expect to see some of the
more than one dozen pieces of airborne debris on the radar data.
But we do not –– we only see one.
If the NTSB believes this farthest piece of debris is the tail, then
the implication is that in the 3.44 seconds between tail separation
(9:15:58.50) and the radar return at 9:16:01.94, the tail has traveled
forward 0.14 NM (850 feet –– almost the length of three football
in those 3.44 seconds. That would mean the tail flew forward (in the
same direction as the plane) at an average speed of 146 knots over
those 3.44 seconds.
Such a feat is aerodynamically impossible according to our contributing
experts. It is also contrary to all witnesses who saw the tail
separate, and reported that the tail immediately fell away from the
airplane. That is why some witnesses described the tail separation as
"a large piece flying off to the north" (as the plane was traveling
As illustrated in Part 1 of our Preliminary Report, the in-flight
an airfoil from an F/A-117 stealth bomber in 1997 showed exactly the
phenomenon –– the airfoil will quickly bleed off any forward momentum
and fall straight down:
this debris seen on radar
at 9:16:01.94 is the vertical tail, it
broke off later
than the NTSB
has declared in order to show up where it
did on radar. This would change the nature of this crash, and prove
the tail separation came after the aircraft was already
out of control.
If this debris is not the tail, then even more so
this challenges the
NTSB's timeline because it means something else separated before the
tail did. We believe this is a critical point, and our assessment is
that this piece on radar at this time is not
the tail. We take
this position because the NTSB believes that when the tail broke
off it created an airborne debris field of more than a dozen pieces (we
agree with them on this point –– this is consistent with the eyewitness
statements and the debris field). More than one of those pieces
would be visible on radar. This does indeed occur –– but not until
later in the crash sequence
–– as we will outline here. Also,
eyewitnesses have stated the tail was not the first debris to separate
(some described debris from the fuselage or wings striking the vertical
and that the tail separated after they noticed the aircraft on fire,
and lower in the sky than normal –– which would also mean the aircraft
had begun it's descent before the tail separated. At this point in the
timeline, at 9:16:01.94, the aircraft has yet
descending. In fact, it won't begin losing altitude for another
A bright flash and
a huge smoke/mist trail emerge from the aircraft (visible on the
tollbooth video). It is at this time the aircraft begins to lose
altitude in a nose-up and/or horizontal attitude (Figure 3
below). The aircraft is at an altitude of 2,428 feet (from the
NTSB's Tollbooth Video Study).
3 - from tollbooth video (video frame 91653 frame 22) –– just after the
frame times are not the same as Air Traffic Control times)
transponder does not reply to the JFK
radar. The transponder reports back to the radar facilities on
the altitude of the airplane. Why wasn't the transponder functioning?
The NTSB hasn't explained this significant malfunction, and the plane
is just beginning its descent (it is still at an altitude of 2,400
feet), still in a horizontal attitude, as
confirmed by the tollbooth video in Figure 3 above.
Therefore, it cannot be argued that the aircraft was wildly out of
9:16:06, and in an unusual attitude, and therefore could not detect the
radar signal and
reply. Along with the cessation of DFDR data, the failure of the
transponder suggests something catastrophic had occurred on board which
negatively affected critical systems.
9:16:06.35 to 9:16:07.11:
These JFK radar returns show
the farthest item is 0.63 NM north of the crash site and there is only one
item at that range. However,
the radar shows two
0.33 and 0.40 NM north of the crash site (Figure 4).
Why is there more
debris closer to the crash site and still no debris near where the NTSB
says the tail separated, at 0.80 NM? That is where most of the debris
should be (if the NTSB timeline is correct).
transponder does not reply to the JFK radar
again. Though the aircraft is descending, it is still in a mostly
horizontal attitude as shown on the tollbooth video (Figure 5).
5 - from tollbooth video
(video frame 91657 frame 20)
9:16:11.06 to 9:16:11.51:
Aside from the aircraft
itself, these JFK radar returns show four airborne
objects behind FL587 (Figure 6). Flight 587 is at an altitude of
approximately 1,600 feet.
Three of the four are 0.09 to 0.46 NM north of the crash site –– a
significant distance from where the NTSB claims the tail and engines
absence of debris at 0.80 NM supports what the majority of
witnesses have told U.S.Read about when the tail separated over Jamaica
Bay and where the majority of rudder debris was in fact recovered ––
much closer to the Bay seawall than the NTSB has reported.
Cockpit Voice Recorder (CVR) recording (assumed
time of aircraft impact).
Taken alone, the JFK radar data suggests that tail separation and
engine separations occurred after the flash and smoke/mist trail seen
on the tollbooth video at 9:16:06.2. That is because the radar
sees only one
piece of debris
before this time. Several pieces of
debris weren't seen until 9:16:11.06 –– more than twelve seconds after
NTSB claims the tail departed
The tail, rudder, and engines were the largest items that
separated in-flight and were therefore the most likely objects to be
seen on radar. But this cluster of objects on radar appeared much
than the NTSB claims the tail and engines fell from the aircraft.
And if this cluster of debris seen by radar after 9:16:06 is the tail
and engines, as we have concluded, what was the debris seen at 9:16:01?
As with all the evidence, a close look at the radar data creates more
challenges for the NTSB in their search for answers –– the radar data
certainly does not support
As we have been outlining in our multi-part Preliminary Report, our
conclusion is that all
evidence suggests the tail departed after
the crew had lost control of
the aircraft –– that tail
separation was not the cause of the crash.
In Part 6 of our report, we will examine the
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