22-03-2014, 09:31 PM
Journal of 9
/11 Studies
Volume 37,
April 2013
1
Radar loss on 9/11
by Paul Schreyer
The radar coverage of the United States airspace is nearly complete.
In particular
the
northeastern
area, where all four
hijackings took place on 9/11, has no
"
gaps
"
whatsoever in
radar coverage.
Nonetheless there was radar loss on 9/11 with respect to the third hijacked
plane, American
Airline
s
Flight
77,
which
was reported to have
hit
the Pentagon.
American 77 took off at 8:20
a.m. EST
and was hijacked more than half an hour later.
It began
to change
its course at 8:54 and, while slowly turning to the left, its transponder was switched off
at 8:56.
1
Until then it had been displayed o
n the radar scopes of air traffic c
ontrol via the Higby
radar site. This was
a
"
beacon
-
only
"
site, meaning a site that could only display transponder
signals.
When
American 77 Ìs transponder was turned off, the plane was no
longer visible to
Higby radar.
2
Image 1: Higby Radar Coverage
Nonetheless the area was cov
ered by additional radar sites.
3
Several sites that
were not
"
beacon
-
only
"
tracked American 77 after its transponder had been turned off.
However the plane
was
lost
to controllers because of the way computers processed the radar data
-
and because of an
unexplained wide
-
ranging radar failure.
For the computer managing the incoming radar data, the airspace is divided into
"
radar sort
boxes
"
(illustrated by the re
d grid in the map above).
Each sort box is 16 nautical miles wide
and each is
assigned to a single radar site.
Additionally each sort box is assigned to a second
"
supplemental
"
radar site for safety.
If the first assigned site is declared to not work pr
operly,
for example because it is
taken down for maintenance, the computer starts to display the data
from the supplemental site on the
c
ontroller Ìs scope.
The data from all other radar sites covering
the area of the sort box is rejected and
not visible a
t all to air traffic controllers. This computer
process is called
"
selective rejection
".
4
Journal of 9
/11 Studies
Volume 37,
April 2013
2
Unfortunately
,
the exact assignments for the radar sort boxes crossed by American 77 during its
flight
are not publicly available.
As former air traffic controller Tom Lusch, an expert on the
problem of
"
selective rejection
,"
pointed out:
"
Missing is the information that informs us how
the radar sort
boxes were adapted.
"
5
It
i
s also unclear if the 9/11 Commission ever obtained
those
specific records.
However
,
the assignments can also be estimated from the distance of the
nearest radar sites to the
specific sort box if it is assumed that the nearest long range radar sites
would
always
be assigned to a sort box.
The spe
cific sort box t
hat
American 77 was crossing when
the transponder was turned off
was
assigned
to the Higby radar site.
Supplemental
to this
was
the
Lynch radar site (see map below).
This precise information
is no
t an
estima
te but was reported by the FAA.
6
Image 2:
Lynch Radar Coverage
Thus, when the controller lost the transponder signal and switched to
"
primary radar
"
on his
scope,
the computer started displaying the radar data received from Lynch.
The problem: Lynch
operated
poorly.
For unknown reasons it
did n
ot
"
see
"
American 77 in the precise area where
the transponder
was turned off.
That is
why the plane got lost for about 8 minutes, exactly when
it turned.
The problem with
the
Lynch radar site was known to air traffic controllers and managers at
the
India
napolis
Air Route Traffic Control Center (Indy Center) before 9/11, as interview notes by
the 9/11 Commission
reveal.
7
However
,
the Commission apparently f
ailed to investigate why
Lynch operated so
poorly and also
why the FAA, being in charge of
the radar sites, had allowed
this.
In fact
,
planes do disappear temporarily from radar from time to time for a number of technical
reasons.
Yet the instance of turning off a transponder in a small zone, internally assigned to a
supplemental radar site wh
ich is known to insiders to be faulty, appears suspicious.
Journal of 9
/11 Studies
Volume 37,
April 2013
3
American 77 reappeared on the scopes of Indy Center only at 9:04 via Lynch radar site. At 9:07
,
the plane apparently crossed into a sort box that was assigned to
the
Bedford radar site and was
subs
equently displayed
via Bedford without a problem.
8
It is
also worth mentioning that Flight 77
did not
turn off its autopilot while being hijacked.
Instead the
autopilot was functioning throughout the radical change in course back to
Washington. It stayed o
n
until approximately 9:08 when it was shut off for thr
ee minutes and
turned on again.
9
Now, what are the conclusions?
Miles Kara, who investigated the issue for the 9/11
Commission,
said
that he was
also
intrigued by the loc
ation of the turn initially
.
However he is
convinced that it
was not more than a coin
cidence.
10
Nonetheless
,
an important question is why
the alleged hijackers
waited for more than half an hour before they took over and turned the
plane.
One can only guess
because there is no cle
ar
explanation for this behavio
r.
One thing
is
ve
ry obvious, however:
the
earlier the plane would have been turned, the more likely the plot
would have been successful.
Why
wait
for more than 30 minutes,
while flying
away from the
intended target?
For exam
ple,
American
Airlines Flight
11 was apparently hijacked only 15
minu
tes after take
-
off.
On the other hand
,
it is
clear from investigating the radar sort box programming that American
77
would have remained completely visible to air traffic control if it
had turned 6 to 8 minutes
before
or even earlier.
W
ere the alleged al Qaeda hijackers aware of this?
We
do not
know, but probably not.
At least
there is no evidence for any contact between al Qaeda operatives and insiders with knowledge of
the Lynch rada
r gap.
Could some planners outside al Qaeda have known?
Yes, this is possible.
As
mentioned, the information was not public, but
was
available
only
to insiders before 9/11.
Therefore
it all depends on a specific interpretation: Was the location of the t
urn a coincidence or
not?
D
isappearing from radar screens actually was essential
for the success of the terrorist Ìs
mission.
What would have
happened if the plane had not
become
lost
to controllers at 8:56?
First, air traffic control w
ould have observed t
he full 180
-
degree turn of American 77.
At 9:00 it
was heading east.
For the past five minutes controllers had tried to contact the plane via radio
without success.
So there was loss of communication
and
the plane was dramatically off course.
Additionally the transponder signal had disappeared.
Altogether, 9:00 a.m. would have been the
appropriate time to alert the military and call for the scrambling of fighter jets.
In reality this
had
not
happened only because, without any radar signal, co
ntro
llers
had apparently
thought th
at th
e
plane had
crashed.
If the military had received the call at 9:00, Langley Air Force Base would have been able to get
fighters in the air at about 9:15.
This was the case at
Otis Air Force Base, where NEADS had
rec
eived a call at
8:38 and the jets were in the air at 8:52.
If the Langley jets had taken off at
9:15, they would have
been vectored to American 77 and would have reached the plane then at
approximately 9:27
about
10 minutes before it
crash
ed
.
It is doub
tful if a shoot
-
down order could have been issued by that time.
But at least
-
and the
following fact is constantly underestimated
-
the fighter pilots could have taken a deep look into
Journal of 9
/11 Studies
Volume 37,
April 2013
4
the
cockpit of the hijacked plane
to
see who was actually at the cont
rols.
This would have
helped to confirm i
f it really was Hani Hanjour,
the alleged pilot, who reportedly
could not
even
fly a Cessna safely, and whose presumed boarding is
not backe
d by any airline check
-
in data.
11
But that
did not
happen because of the loss of radar
precisely
at the turning point of American
77.
About the author:
Paul Schreyer, born 1977, is a German author and journalist,
writing for the
online journals
Global Research
, Telepolis,
and others. He is author of the b
ook
"Inside 9/11."
At the Journal of 9/11 Studies he previously published the paper
"
Anoma
lies of the air defense
on 9/11,"
in October 2012. His website is http://www.911
-
facts.info.
Notes:
(1) 9/11 Commission Report, pp. 9, 25
http://govinfo.library.unt.edu/911/report/911Report.pdf
(2) FAA Memorandum
"
AAL 77 Flight Path Information
,"
17.09.01
http://de.scribd.com/doc/13950396/T8
-
B3
-
FAA
-
Gl
-
Region
-
Fdr
-
AA
-
77
-
Radar
-
Info
-
Emails
-
Withdrawal
-
Notice
-
Memo
-
and
-
Questions
(3) Tom Lusch Ìs Website, June 2010
http://tomlusch.com/tomlusch/tomlusch/AAL77.html
(4)
"
Selective Rejection of Low Altitude Radar Data at Air Route Traffic Control Centers: An
Unsatisfactory Compromise
,"
26.09.1988, Thomas G. Lusch
http://www.tomlusch.com/tomlusch/tomlusc...SelRej.pdf
(5) Email from Tom Lusch, 11.01.13
(6) FAA Memorandum „AAL 77 Flight Path Information", 17.09.01
http://de.scribd.com/doc/13950396/T8
-
B3
-
FAA
-
Gl
-
Region
-
Fdr
-
AA
-
77
-
Radar
-
Info
-
Emails
-
Withdrawal
-
Notice
-
Memo
-
and
-
Questions
(7) Tom Lusch Ìs Website, see
"
May 7, 2012 update
"
http://tomlusch.com/tomlusch/tomlusch/AAL77.html
9/11 Commission, Interview notes Charles Thomas, 04.05.04
http://tomlusch.com/tomlusch/tomlusch/AAL77_files/NARA to Lusch 20090820.pdf
(8) Email from Tom Lusch, 15.01.13, information based on NTAP flight data for AAL 77
(9) NTSB, Office of Research and Engineering, Flight path study
-
American Airl
ines Flight 77,
February 19, 2002
http://www.gwu.edu/~nsarchiv/NSAEBB/NSAEBB196/doc02.pdf
(10) Email from Miles Kara, 13.11.12
9/11 Blogger,
"
Discussion with Miles Kara about 9/11 air d
efense
,"
16.12.12
http://911blogger.com/news/2012
-
12
-
16/discussion
-
miles
-
kara
-
about
-
911
-
air
-
defense
(11) 9/11 Commission Report, p. 452, note 11
http://govinfo.library.unt.edu/911/report/911Report.pdf
9/11 Commission, Team 7, Box 18,
"
American Airlines Ì response to the February 3, 2004
requests by the 9/11 Commission
C&F Ref: DTB/CRC/28079
,"
15.03.04, Desmond T. Barry /
Condon & Forsyth LLP, on behalf of American Airlines, p. 96
http://www.911myths.com/images/7/71/Team7_Box18_AAL
-
QFR
-
Responses.pdf
/11 Studies
Volume 37,
April 2013
1
Radar loss on 9/11
by Paul Schreyer
The radar coverage of the United States airspace is nearly complete.
In particular
the
northeastern
area, where all four
hijackings took place on 9/11, has no
"
gaps
"
whatsoever in
radar coverage.
Nonetheless there was radar loss on 9/11 with respect to the third hijacked
plane, American
Airline
s
Flight
77,
which
was reported to have
hit
the Pentagon.
American 77 took off at 8:20
a.m. EST
and was hijacked more than half an hour later.
It began
to change
its course at 8:54 and, while slowly turning to the left, its transponder was switched off
at 8:56.
1
Until then it had been displayed o
n the radar scopes of air traffic c
ontrol via the Higby
radar site. This was
a
"
beacon
-
only
"
site, meaning a site that could only display transponder
signals.
When
American 77 Ìs transponder was turned off, the plane was no
longer visible to
Higby radar.
2
Image 1: Higby Radar Coverage
Nonetheless the area was cov
ered by additional radar sites.
3
Several sites that
were not
"
beacon
-
only
"
tracked American 77 after its transponder had been turned off.
However the plane
was
lost
to controllers because of the way computers processed the radar data
-
and because of an
unexplained wide
-
ranging radar failure.
For the computer managing the incoming radar data, the airspace is divided into
"
radar sort
boxes
"
(illustrated by the re
d grid in the map above).
Each sort box is 16 nautical miles wide
and each is
assigned to a single radar site.
Additionally each sort box is assigned to a second
"
supplemental
"
radar site for safety.
If the first assigned site is declared to not work pr
operly,
for example because it is
taken down for maintenance, the computer starts to display the data
from the supplemental site on the
c
ontroller Ìs scope.
The data from all other radar sites covering
the area of the sort box is rejected and
not visible a
t all to air traffic controllers. This computer
process is called
"
selective rejection
".
4
Journal of 9
/11 Studies
Volume 37,
April 2013
2
Unfortunately
,
the exact assignments for the radar sort boxes crossed by American 77 during its
flight
are not publicly available.
As former air traffic controller Tom Lusch, an expert on the
problem of
"
selective rejection
,"
pointed out:
"
Missing is the information that informs us how
the radar sort
boxes were adapted.
"
5
It
i
s also unclear if the 9/11 Commission ever obtained
those
specific records.
However
,
the assignments can also be estimated from the distance of the
nearest radar sites to the
specific sort box if it is assumed that the nearest long range radar sites
would
always
be assigned to a sort box.
The spe
cific sort box t
hat
American 77 was crossing when
the transponder was turned off
was
assigned
to the Higby radar site.
Supplemental
to this
was
the
Lynch radar site (see map below).
This precise information
is no
t an
estima
te but was reported by the FAA.
6
Image 2:
Lynch Radar Coverage
Thus, when the controller lost the transponder signal and switched to
"
primary radar
"
on his
scope,
the computer started displaying the radar data received from Lynch.
The problem: Lynch
operated
poorly.
For unknown reasons it
did n
ot
"
see
"
American 77 in the precise area where
the transponder
was turned off.
That is
why the plane got lost for about 8 minutes, exactly when
it turned.
The problem with
the
Lynch radar site was known to air traffic controllers and managers at
the
India
napolis
Air Route Traffic Control Center (Indy Center) before 9/11, as interview notes by
the 9/11 Commission
reveal.
7
However
,
the Commission apparently f
ailed to investigate why
Lynch operated so
poorly and also
why the FAA, being in charge of
the radar sites, had allowed
this.
In fact
,
planes do disappear temporarily from radar from time to time for a number of technical
reasons.
Yet the instance of turning off a transponder in a small zone, internally assigned to a
supplemental radar site wh
ich is known to insiders to be faulty, appears suspicious.
Journal of 9
/11 Studies
Volume 37,
April 2013
3
American 77 reappeared on the scopes of Indy Center only at 9:04 via Lynch radar site. At 9:07
,
the plane apparently crossed into a sort box that was assigned to
the
Bedford radar site and was
subs
equently displayed
via Bedford without a problem.
8
It is
also worth mentioning that Flight 77
did not
turn off its autopilot while being hijacked.
Instead the
autopilot was functioning throughout the radical change in course back to
Washington. It stayed o
n
until approximately 9:08 when it was shut off for thr
ee minutes and
turned on again.
9
Now, what are the conclusions?
Miles Kara, who investigated the issue for the 9/11
Commission,
said
that he was
also
intrigued by the loc
ation of the turn initially
.
However he is
convinced that it
was not more than a coin
cidence.
10
Nonetheless
,
an important question is why
the alleged hijackers
waited for more than half an hour before they took over and turned the
plane.
One can only guess
because there is no cle
ar
explanation for this behavio
r.
One thing
is
ve
ry obvious, however:
the
earlier the plane would have been turned, the more likely the plot
would have been successful.
Why
wait
for more than 30 minutes,
while flying
away from the
intended target?
For exam
ple,
American
Airlines Flight
11 was apparently hijacked only 15
minu
tes after take
-
off.
On the other hand
,
it is
clear from investigating the radar sort box programming that American
77
would have remained completely visible to air traffic control if it
had turned 6 to 8 minutes
before
or even earlier.
W
ere the alleged al Qaeda hijackers aware of this?
We
do not
know, but probably not.
At least
there is no evidence for any contact between al Qaeda operatives and insiders with knowledge of
the Lynch rada
r gap.
Could some planners outside al Qaeda have known?
Yes, this is possible.
As
mentioned, the information was not public, but
was
available
only
to insiders before 9/11.
Therefore
it all depends on a specific interpretation: Was the location of the t
urn a coincidence or
not?
D
isappearing from radar screens actually was essential
for the success of the terrorist Ìs
mission.
What would have
happened if the plane had not
become
lost
to controllers at 8:56?
First, air traffic control w
ould have observed t
he full 180
-
degree turn of American 77.
At 9:00 it
was heading east.
For the past five minutes controllers had tried to contact the plane via radio
without success.
So there was loss of communication
and
the plane was dramatically off course.
Additionally the transponder signal had disappeared.
Altogether, 9:00 a.m. would have been the
appropriate time to alert the military and call for the scrambling of fighter jets.
In reality this
had
not
happened only because, without any radar signal, co
ntro
llers
had apparently
thought th
at th
e
plane had
crashed.
If the military had received the call at 9:00, Langley Air Force Base would have been able to get
fighters in the air at about 9:15.
This was the case at
Otis Air Force Base, where NEADS had
rec
eived a call at
8:38 and the jets were in the air at 8:52.
If the Langley jets had taken off at
9:15, they would have
been vectored to American 77 and would have reached the plane then at
approximately 9:27
about
10 minutes before it
crash
ed
.
It is doub
tful if a shoot
-
down order could have been issued by that time.
But at least
-
and the
following fact is constantly underestimated
-
the fighter pilots could have taken a deep look into
Journal of 9
/11 Studies
Volume 37,
April 2013
4
the
cockpit of the hijacked plane
to
see who was actually at the cont
rols.
This would have
helped to confirm i
f it really was Hani Hanjour,
the alleged pilot, who reportedly
could not
even
fly a Cessna safely, and whose presumed boarding is
not backe
d by any airline check
-
in data.
11
But that
did not
happen because of the loss of radar
precisely
at the turning point of American
77.
About the author:
Paul Schreyer, born 1977, is a German author and journalist,
writing for the
online journals
Global Research
, Telepolis,
and others. He is author of the b
ook
"Inside 9/11."
At the Journal of 9/11 Studies he previously published the paper
"
Anoma
lies of the air defense
on 9/11,"
in October 2012. His website is http://www.911
-
facts.info.
Notes:
(1) 9/11 Commission Report, pp. 9, 25
http://govinfo.library.unt.edu/911/report/911Report.pdf
(2) FAA Memorandum
"
AAL 77 Flight Path Information
,"
17.09.01
http://de.scribd.com/doc/13950396/T8
-
B3
-
FAA
-
Gl
-
Region
-
Fdr
-
AA
-
77
-
Radar
-
Info
-
Emails
-
Withdrawal
-
Notice
-
Memo
-
and
-
Questions
(3) Tom Lusch Ìs Website, June 2010
http://tomlusch.com/tomlusch/tomlusch/AAL77.html
(4)
"
Selective Rejection of Low Altitude Radar Data at Air Route Traffic Control Centers: An
Unsatisfactory Compromise
,"
26.09.1988, Thomas G. Lusch
http://www.tomlusch.com/tomlusch/tomlusc...SelRej.pdf
(5) Email from Tom Lusch, 11.01.13
(6) FAA Memorandum „AAL 77 Flight Path Information", 17.09.01
http://de.scribd.com/doc/13950396/T8
-
B3
-
FAA
-
Gl
-
Region
-
Fdr
-
AA
-
77
-
Radar
-
Info
-
Emails
-
Withdrawal
-
Notice
-
Memo
-
and
-
Questions
(7) Tom Lusch Ìs Website, see
"
May 7, 2012 update
"
http://tomlusch.com/tomlusch/tomlusch/AAL77.html
9/11 Commission, Interview notes Charles Thomas, 04.05.04
http://tomlusch.com/tomlusch/tomlusch/AAL77_files/NARA to Lusch 20090820.pdf
(8) Email from Tom Lusch, 15.01.13, information based on NTAP flight data for AAL 77
(9) NTSB, Office of Research and Engineering, Flight path study
-
American Airl
ines Flight 77,
February 19, 2002
http://www.gwu.edu/~nsarchiv/NSAEBB/NSAEBB196/doc02.pdf
(10) Email from Miles Kara, 13.11.12
9/11 Blogger,
"
Discussion with Miles Kara about 9/11 air d
efense
,"
16.12.12
http://911blogger.com/news/2012
-
12
-
16/discussion
-
miles
-
kara
-
about
-
911
-
air
-
defense
(11) 9/11 Commission Report, p. 452, note 11
http://govinfo.library.unt.edu/911/report/911Report.pdf
9/11 Commission, Team 7, Box 18,
"
American Airlines Ì response to the February 3, 2004
requests by the 9/11 Commission
C&F Ref: DTB/CRC/28079
,"
15.03.04, Desmond T. Barry /
Condon & Forsyth LLP, on behalf of American Airlines, p. 96
http://www.911myths.com/images/7/71/Team7_Box18_AAL
-
QFR
-
Responses.pdf
"Let me issue and control a nation's money and I care not who writes the laws. - Mayer Rothschild
"Civil disobedience is not our problem. Our problem is civil obedience! People are obedient in the face of poverty, starvation, stupidity, war, and cruelty. Our problem is that grand thieves are running the country. That's our problem!" - Howard Zinn
"If there is no struggle there is no progress. Power concedes nothing without a demand. It never did and never will" - Frederick Douglass
"Civil disobedience is not our problem. Our problem is civil obedience! People are obedient in the face of poverty, starvation, stupidity, war, and cruelty. Our problem is that grand thieves are running the country. That's our problem!" - Howard Zinn
"If there is no struggle there is no progress. Power concedes nothing without a demand. It never did and never will" - Frederick Douglass