"aa77" Final Approach Ground Speed Determination From The 84rades Radar Data, 84Rades and FDR data mutually INCONSISTENT?

post Jan 2 2009, 10:26 PM
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In 2007 The Pilots for 911Truth obtained the Flight Data Recorder (FDR) data of "AA77". In the same year in autumn John Farmer obtained the 84th. Radar Evaluation Squadron, Hill AFB, UT (84Rades) USAF/NEADS radar data from 9/11.
Booth are extensive data sets and booth are provided with flightpath analyses. - In case of FDR data there are the flight simulations which include the graphic projection of the main flight parameters (as apeed, altitude, bank angle, throttle...); in case of the 84Rades data there are then the flightpath studies of all 4 aircrafts (the Official conspiration theory considers being the planes used in 9/11 attacks) - made as projects in RS3 radar data decoding and screening software. Booth data sets were obtained via FOIA request from National Transportation and Safety Board (NTSB) - which is the main federal institution-agency which should investigate all aviation accidents. Both sets therefore could be considered as the official data about 9/11 events and therefore should be considered as a proof which could also serve for law enforcement purposes - as the 84Rades data in fact did, because they were provided for FBI investigation already 2 days after the tragic events of 9/11.

The purpose of this analysis was originaly solely to determine the range of possible speeds the "AA77" could fly during its final approach to the Pentagon - to determine the speeds of the "AA77" final approach from 84Rades data. For the analysis I've used the last 8 blips on The Plains ARSR-3 radar (PLA) which is located approximately 30 nautical miles (nmi) northwestwest from the Pentagon - so the "AA77" was really well in the range of the radar.
(The real range of PLA radar in the direction the "AA77" was flyiing from was empiricaly derived from how far the PLA radar have "seen" other planes in that southwestward direction - which the PLA radar did even in distance of approx. 190 nmi - although the "AA77" reappears - after a period of ~19 minutes of "invisibility" - on the PLA radar at the range of 147.5 nmi - which itself is weird and casts doubts about the 84Rades data credibility. But the 84Rades data credibility was not the main question of the original analysis).

Originally I posted the speed analysis in a thread in the Study, which was about addressing of the GL "arguments" against the "northern path".
However the results of the original analysis seemed to me be in such a contradiction to the results of the NTSB "AA77" flightpath study derived from FDR, that I decided to make a separate topic, to discuss this weird issue.

Last "AA77" blips from 84Rades and the groundspeed derived

Here are the last "AA77" PLA radar data decoded by USAF rs3 software:

[click the upper right corner to enlarge...or SOURCE]

On the screenshot from rs3 software you can see the data of the last 8 blips recorded by PLA radar. In fact there should be not 8, but 9 blips - the sweeping period of the radar is approx. 11.9 seconds - so there is surely one blip missing - which one can maybe expect, because the plane was probably already in a very low altitude above terrain.
We don't see any radar height in the data, because ARSR-3 radars don't read it, and we also don't see any Mode C altitude either, because the PLA radar didn't read any, most probably because the "AA77" didn't transmit any from the supposedly switched-off transponder.

Now we can project the Lat/Lon blip data into GoogleEarth to measure the distance between them, which will help us to determine the range of speeds the "AA77" could fly at its final approach. ( Blips are numbered with the red numbers, the long numbers are the timestamps of each blip - note they're all 4 hours after the actual eastern time when the events happened - which could be attributed to the use of an universal time by the US army - but this doesn't affect my analysis):

[click the upper right corner to enlarge...or SOURCE]

The projection of the blips beggins with the No.8 - it is the end of the big ~330 turn the "AA77" did while descending. Then it continues with 7. and from 6. is the trajectory already quite very straight towards the Pentagon. I've used the Google Earth measurement tool (not the calculator embedded in the RS3 software) to determine the distances between the projections of the blips. From it and the exact radar timestamps (with accuracy of 0.005 seconds) I was able to count the possible groundspeeds estimations:
I use this simple equation:

(number of seconds in hour/numberof seconds of the flight period)*number of miles travelled=speed in miles per hour
distance blip 7. - 1. = 6.83 mi
7. 13:36:24.715
1. 13:37:35.890
6.83 mi in 71.175 sec. = (3600/ 71.175)*6.83 = 345.46 mph

distance blip 6. - 1. = 5,68 mi
6. 13:36:36.555
1. 13:37:35.890
5.68 mi in 59.335 sec. = 344.6 mph

distance blip 5. - 1. = 4.60 mi
5. 13:36:48.395
1. 13:37:35.890
4.60 mi in 47.495 sec. = 348,7 mph

distance blip 4. - 1. = 3.14 mi
4. 13:37:00.275
1. 13:37:35.890
3.14 mi in 35.615 sec. = 317,4 mph

distance blip 3. - 1. = 1.90 mi
3. 13:37:12.190
1. 13:37:35.890
1.90 mi in 23.7 sec. = 288,6 mph

distance blips 8. - 6. - 1. = 1.98 + 5.68 = 7.66 mi
8. 13:36:12.875
1. 13:37:35.890
7.66 mi in 83.015 sec. = 332.2 mph

distance blips 8. - 7. - 6. - 5. - 4. - 3. - 1. = 0.75+1.22+1.07+1.50+1.26+1.90 = 7.7 mi ("average speed for the "straight period")
8. 13:36:12.875
1. 13:37:35.890
7.7 mi in 83.015 sec. = 333.9 mph

The blip X. is quite weird (although included in the 84Rades "AA77" flightpath study which is included in the original set of the disks provided by USAF to FBI). The timestamp is again the increase of ~11.9 sec. - so if we count then the speed would drop even more considerably.

distance blips 6. - X. = 5.7 mi
6. 13:36:36.555
X. 13:37:47.810
5.7 mi in 71.255 sec. = 288 mph
But this blip really - it could be anything but not a "AA77" position at the given time - so we should exclude it from our analysis.
I call this blip X. - because its position is quite inconsistent with the other blips (which look quite consistent with each other). Some say it's the radar echo not from the "AA77" itself, but of the fireball or smoke from the Pentagon explosion.

Average groundspeed for whole the 330 turn

Now for the illustration and further comparison I will plot the whole 330 turn. The blue points are the projected blips from the PLA radar. The numbers are timestamps shortened just to minutes : seconds . thousands of seconds. The yellow points are projections of the Gibbsboro radar (- GIB - the ARSR-4 radar located ~110 nmi northeast from Pentagon in NJ) blips - which are also available in the 84Rades data set for "AA77" in some cases (They're missing in majority of cases, mostly missing also the important information of ARSR-4 radar type - and that's the height data - but GIB search blips are readable just in the case of the part of the 330 turn at least for the positioning data, which are in good accord with the PLA data...although some of the blips - which are in the "raw" dataset - are "ommited" from the "AA77" flightpath study provided for FBI by 84Rades in their "AA77" flightpath study!...). The GIB pattern clearly copies the pattern of the PLA radar blips, although the average distance difference between the PLA and GIB blips projected for a same sweep time is ~0.3 nmi - which would almost exactly fit into the combined accuracy range as specified by 84Rades in the 84Rades cover letter.

[click the upper right corner to enlarge...or SOURCE]

If we measure the combined distance with the Google Earth measurement tool for the whole above marked path, we come to 31.09 miles. The timestamps are:
beginning: 32:26.360 , end: 37:47.810 -> the time difference: 321.45 seconds.
So we can count average speed for the whole projected path (3600/321.45)*31.09 = 348.18 mph



The ground speeds for the last 8 sweep periods of PLA are in the range from 288 to 380 mph - or between ~245 to ~330 knots.


We can also conclude that - if the 84Rades data are real and the measuring in the Google Earth is sufficiently accurate - then the ground speed of the "AA77" during the last 1.5 minutes of the flight didn't exceeded ~365 knots and most probably not even ~330 knots. So then the speed of "420 knots"
- proposed by some - (or even 465 knots as is the last speed in FDR) in scope of 84Rades data looks a bit like a nonsense.
(The FDR average speed for last 44 seconds of flight is >400 mph = ~350 knots for last 33 seconds even ~450 mph = ~390 knots)
[this two conclusions A. and B. are dependent on the accuracy of the Google Earth measurement tool and we can't rely on it - I've put it here just because it was the core of my original analysis]


The average ground speed for the last 8 sweep periods of the PLA radar is 333,9 mph or ~290 knots. But the average speed for the whole 330 turn was ~348 mph or ~303 knots - so there is a high probability, that the "AA77" decreased its speed during the last 1.5 minute of the flight NOT INCREASED - which is in direct contradiction with the FDR data decoded both in FDR files and in the NTSB animation. [and this conclusion is based on relative computing - virtually independent on the Google Earth measurement tool accuracy!!]


The inconsistence between speed pattern derived from the 84Rades data and the speed pattern derived from the FDR is inspectional.

Although we can't be exactly sure about the Lat/Lon positions derived - because the accuracy of the radar positioning is according to 84Rades cover letter within range of 1/8nmi (0.144 mi) - which still can't explain so huge difference between the speeds derived from FDR and speeds derived form 84Rades and at all it can't explain the opposite speed increase/decrease pattern - which is opposite in FDR and 84Rades respectively for the last ~5 minutes of the "AA77" flight. This leads me to conclusion that either the FDR or 84Rades data (or booth) are at least partially a fake.

The accuracy assesment of the PLA radar

From the 84Rades data can be derived the theoretical accuracy range of Lat/Lon positioning. For this purpose would be good to describe, how the Lat/Lon data are created from the raw radar data. The Lat/Lon position of the blip is determined by this raw data:
1. Timestamp - accuracy
0.005 seconds
2. Range - accuracy of
0.125 nmi = 0.144 mi = 231 meters
Azimut degree - accuracy 0.001 of one angular degree
(+ 4. Exact Lat/lon position of the radar which is fixed)

So, if we assume an object is flying at maximum speed derived from our analysis - 380 mph then
in - 0.01 seconds can travel 380/(100*3600) miles = 0.001055 miles = 1.697 meter;
2. the range accuracy is 2*0.144 miles = 462 meters (the actual position of the flying object can fluctuate in a circle of the diameter of 462 meters); and
3. maximum range (at the blip No. 1) from the PLA radar was exactly 30 nmi = 34.523 miles = 55559.382912 meters - so the 0.002 angular degree circle section of the circle with the radius of
55559.382912 meters = 0.002*((2π*55559.382912)/360) = 1.939 meter.

We see, that the cummulative accuracy of the radar depends almost solely on the Range data which are the least exact. The cummulative error range for positioning measurement of our "AA77" object is then ~
233 meters = 0.144 miles = 0.125 nmi, which is the same value noted in the 84Rades cover letter (at the page 2, paragraph 2) and it is a distance of aprox. the "radius" of the circle the Pentagon is circumsribed around.

If we then assume a chaotic Gaussian normal distribution scatter of the error, then for the whole 31.09 miles path (with computed groundspeed of 348.18 mph it signifies just:
100*(1/(31.09/0.144)) = 0.0046317*100 = 0.46%! (possible error of computed speed)

for 7.7 miles path (distance measured from blip 8. to 1. (with the computed ground speed of 333.9 mph) then:
100*(1/(7.7/0.144)) 0,0187013 = 1.87%

Cummulatively for the comparison - of the whole 330 path with the last straight segment from blip 8. to 1. - is then the maximum error 0.46%+1.87% = 2,33%. But the difference between 348 mph and 333.9 mph is (348.18-333.9)/(348.18/100) = 4.1% - and I therefore can assume (if I don't make a mistake somewhere) that the conclusions C. and D. are statistically proven - because even if the error of the radar measurement would be at its maximum value, the average groundspeed of the whole 330 maneuvre is here proven to be anyway slightly higher then the average groundspeed in the last straigt section between the blips 8. to 1. - And this, if I understand it well, directly contradicts the FDR data where (in contradiction to this derivations from 84Rades) the speed of the last period is really significantly higher (due to increasing of the throttle to max and a straight flight) then the speed during the previous maneuvre.

But it would be good to corroborate it again for example with the estimated speed between the blips 4. and 1. :
The estimated speed there is 317.4 mph, the distance travelled is 3.14 miles - so the statistically estimated error of position measurement would be: 100*(1/(3.14/0.144))+0.46=0.04586 = 5%. But the difference between 348.18 mph and 317.4 mph = (348.18-317.4)/(348.18/100) = 8.84%

And for the blips 3. to 1. the estimated speed there is 288.6 mph, distance travelled 1.9 miles - so the statistically estimated error of position measurement would be 100*(1/(1.9/0.144))+0.46 = 8% - but the difference between 348.18 mph and 288.6 mph is (348.18-288.6)/(348.18/100) = 17.1% - even more convincing...

Well, I'm not completely convinced about the 84Rades data credibility - in fact I don't the data are untampered - there are too much of it at least "missing" (as the missing period of "UA175" after the start on NOR radar, as the hardly explainable extensive "invisibility" periods on the "AA77" and "UA93"journeys...) but if I would really need (which I don't) to decide which of the two data sets (FDR or 84Rades) are more credible, I would chose the 84Rades - because the data set was supposedly created almost immediately after the 9/11 events and immediately handed to the law enforcement - so the space of time for altering, manipulating or forging of the data would be much shorter (~2. days) and would probably consist just of a "deleting" - than in the case of the FDR data - which rested unpublished nor handed to law enforcement literally for years, so there was plenty of time to forge it. Circumstational reasons for this choice would be also the fact, that the FDR was recovered on unknown location and therefore there is not an undisturbed chain of custody - which would in case of the legal proceedings mean, that such a proof would be inadmissible. But the sole fact, that the NTSB would provide the public with the two mutually contradictory datasets about the most heinous terrorist crimes in the american history would be in my opinion surely a cogent argument for beginning an investigation of NTSB. ...Yes, sure, who would do anything like that...

Positioning source:
The public Google maps source for my private Google Earth research and subsequent drawings


NOTE: The 84Rades data originated from NORAD-USAF radars (and subsequently were reported about by 84 Radar Evaluation Squadron at Hill AFB in Utah - to FBI - already on September 13 2001 - and then to NTSB) were obtained on FOIA request last year by John Farmer aka BCR-bluecollarrepublican, former 911Ommissioner, and subsequently published. John Farmer then shortly after even established the public forum dedicated solely to the research of the 84Rades data.
But when I posted there in autumn 2007 serious posts discussing the numerous anomalies in the data (and also my doubts about the overall credibility of the data - arising from the numerous weird issues in it) the forum was almost immediately after my postings deleted as a whole - not just my posts, or the respective thread - the whole forum was wiped from the internet. To this day I don't know if it was deleted by the John Farmer himself or by somebody else. - When I'd then asked John Farmer via email what happened with the 84Rades forum (I naively thought it was moved somewhere) I've received just a laconical reply: "It no longer exists...." After it I didn't get any further communication from him anymore, even I've tryied it several times.
Fortunately I still keep the backup copies of the whole data sets - in the state as it was first published - in the original ISO rar archives - which can prove or disproove the authenticity with numerous timestamps in the many files contained.

I please the reader in advance to forgive me the possible mistakes in the grammar - as I'm not an English native. This analysis is just an inspiration for the deeper study of the 84Rades vs. FDR.
This is not a "finished scientific paper", it's just a suggestion where the search for convincing proofs might be directed. - I think, that if there would be above any doubt proven, that the FDR and 84Rades data significantly differ in the inner consistency of the data patterns - then it would be in my opinion another quite strong proof of the coverup. And who makes a coverup is usually the perpetrator or its accomplice.

This post has been edited by tumetuestumefaisdubien: Apr 4 2015, 09:21 AM
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Posts in this topic
- tumetuestumefaisdubien   "aa77" Final Approach Ground Speed Determination From The 84rades Radar Data   Jan 2 2009, 10:26 PM
- - JFK   You may be interested in comparing your results wi...   Jan 2 2009, 10:48 PM
|- - tumetuestumefaisdubien   QUOTE (JFK @ Jan 1 2009, 01:48 AM) You ma...   Jan 3 2009, 04:40 AM
- - dMole   Thanks tume. JFK and I had a couple of related th...   Jan 16 2009, 10:40 PM
- - tnemelckram   I thought I'd add to Tumes' RADES Radar Pl...   Jan 17 2009, 09:42 PM
- - dMole   I split the Google Earth-specific posts to Researc...   Jan 20 2009, 03:02 PM
- - tnemelckram   Corrected link for Post 5 above, also not showing ...   Jan 20 2009, 10:12 PM
- - dMole   For the 4 resultant vectors: red ADW= brg 61 degr...   Jan 21 2009, 12:19 AM
- - tnemelckram   Hi dMole: Thank you for your quick work. You did...   Jan 21 2009, 05:46 PM
- - rob balsamo   Interesting work guys. It appears Radar plots from...   Jan 22 2009, 09:35 AM
- - dMole   OK, here is the CAD/graphical method I used to ...   Jan 23 2009, 02:39 AM
- - dMole   I forgot to post the bearings of those resultant h...   Jan 23 2009, 03:25 AM
- - tnemelckram   Hi dMole! Thanks for quickly putting the RADE...   Jan 24 2009, 05:31 PM
- - dMole   TN, I get 6 decimal places in this version of Goog...   Jan 24 2009, 06:39 PM
|- - tnemelckram   Hi dMole! QUOTE TN, I get 6 decimal places in...   Jan 24 2009, 11:03 PM
|- - dMole   QUOTE (tnemelckram @ Jan 24 2009, 08:03 P...   Jan 25 2009, 12:54 AM
|- - dMole   QUOTE (dMole @ Jan 24 2009, 09:54 PM) I...   Jan 25 2009, 06:25 AM
- - tnemelckram   Annanudderting: It looks like it would take a hel...   Jan 24 2009, 06:52 PM
|- - dMole   QUOTE (tnemelckram @ Jan 24 2009, 03:52 P...   Jan 24 2009, 07:13 PM
- - dMole   OK, on that RADES resultant displacement vector (R...   Jan 25 2009, 02:07 AM
- - dMole   [Reply to TN's Google Earth work- some posts h...   Jan 25 2009, 03:19 AM
- - tnemelckram   Corrected Link for Post No. 19 above: http://www....   Jan 25 2009, 12:34 PM
- - tnemelckram   Hi dMole! 1. I posted a corrected link for my...   Jan 25 2009, 01:00 PM
- - dMole   While these are likely the DME/VOR beacon location...   Jan 31 2009, 02:31 AM
- - dadeets   QUOTE (tumetuestumefaisdubien @ Jan 2 2009, 0...   Oct 25 2010, 07:23 PM
|- - woody   QUOTE (dadeets @ Oct 25 2010, 11:23 PM) T...   Oct 26 2010, 04:11 PM
- - dadeets   QUOTE (tumetuestumefaisdubien @ Jan 2 2009, 1...   Oct 26 2010, 05:06 PM
|- - tumetuestumefaisdubien   QUOTE (dadeets @ Oct 26 2010, 09:06 AM) T...   Dec 26 2010, 07:14 PM
|- - Paul   QUOTE (tumetuestumefaisdubien @ Dec 27 2010, ...   Jan 10 2011, 12:48 AM
|- - tumetuestumefaisdubien   QUOTE (Paul @ Jan 9 2011, 04:48 PM) So le...   Jan 10 2011, 12:05 PM
- - rob balsamo   Guys, I just remembered, I think tume is out o...   Oct 26 2010, 05:35 PM
- - woody   Thanks for the link, Rob. I have to check to the...   Oct 27 2010, 04:54 PM

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