New FDR Decode

Originally posted by turbofan
reply to post by trebor451

 

What does it take for you guys to put up a real debate and answer questions?

What is the tolerance of commercial category pressure altimeters?

John stated they are "highly inaccurate".

Do you agree?

Yes.

Now, explain the purpose of radio altimeters.

Originally posted by turbofan
reply to post by trebor451

 

What does it take for you guys to put up a real debate and answer questions?

What is the tolerance of commercial category pressure altimeters?

John stated they are "highly inaccurate".

Do you agree?

Please backup your reply with FAA and manufacturer data. I'll await
either reply and then post the real data for the readers to view.

Let me ask you this.....what would you place your life on, TF, at 50 feet and 500 knots........a barometric altimeter? or a radar altimeter? You can spout "tolerances" all day till the cows come home.....what would you base your life on?

As far as your lament about debate, I ask again.....PfT "research"? Tell me how one debates a club about these issues when they have shown a repeated inability to understand a) standard published departures from a military airfield, b) flight procedures around a prohibited area such as P-56, c) how NOTAMS are disseminated to airfields and air facilities throughout the US, d) air defense capabilities in and around the Pentagon, e) the structural integrity of Boeing aircraft (i.e. wings ripping off at the horrific speed of 450 KTAS.

Again, you people give yourself too much credit. In many, many cases you have absolutely no idea what you are talking about, and you ask me why there is no debate? Why did Cap't Bob kick me off his forum?

Seriously, TF, where would you place your life at 50 feet and 500 knots.

I don't understand why there is any attempt to correlate 77's FDR data with a flyover. At all. Because if it was a flyover, and did not hit, then why would the FDR itself be anywhere else but in the plane even to this day- assuming, that is, that the plane and all its passengers wasn't remotely piloted out to deep ocean and destroyed?

The bottom line is no one, including the FBI, can or will confirm that the FDR provided to the NTSB was indeed the FDR from AA77. The serial numbers were missing, as has been documented so many times here and elsewhere.

And to this day I have not seen one credible, or rational explanation for THAT.

[edit on Tue Oct 27th 2009 by TrueAmerican]

Originally posted by TrueAmerican
The serial numbers were missing, as has been documented so many times here and elsewhere.

And to this day I have not seen one credible, or rational explanation for THAT.

The serial numbers were missing? How would you know that unless you have personally seen the FDR/CVR in question? Was there a news report/news release that specifically stated the "serial numbers were missing"?

This is just another example of the Troother movement thinking they are more important than they are.

Why in the world would the FBI care in any way, shape or form that they need to make *you* happy by providing *you* with the serial numbers of the FDR?

Its *much* more fun to not give them to you and watch you people get apoplectic with indignation and rage that YOU donot hav ethe information.

How DARE the FBO not recognize PfT! *burp*

As to the accuracy of a pressure altimeter: considering the resolution of the adjustment which is 0.01" Hg increments and 1" Hg representing near enough to 1000', we could expect an accuracy in the order of +/- 10' if the instrument was perfect in every way. In practise the accuracy would be somewhat worse than that. A radar altimeter would be an order of magnitude better for very low altitude measurements and immune to air pressure anomalies produced at extremely low level, high speed flight.

Just my 2c

reply to post by Pilgrum


Turbo understands that pressure altitude is not used for landing purposes due to inaccuracy. That is why for IFR radio altimeters are used. The FDR captures readings from 4 different RA's located at different positions on the underside of the aircraft. All four show a consistent trajectory in this case. He has just run out of fly-over arguments.

If the FBI released every photograph and file they had, there would still be those who argue what they believe instead of what the evidence demonstrates. And so the FBI has not released the serial number of the fdr? What is the serial number supposed to be and how do you know what it is supposed to be. Seems to me that if they did release a serial number, then it will mean nothing to those who want it because none of them know what it should be.

reply to post by turbofan


I'm not totally up to date on all the discussions related to this FDR data that have have taken place here and particularly, on other forums I don't spend time at so just a question or 2 you may be able to answer for me:

The first decode of this data independant of NTSB was done in association with PFT members somewhat secretly (reasons for that are not important) and I'm talking about the 'readout2' I've seen mention of.

That particular decoding must have revealed the existance of the extra (incomplete) packet at the end of the raw file consisting of the altitude data we're discussing here now. Have you acknowledged that data prior to W Stutts's decode and revelation of it and, if not, why?

The reason I ask is that it appears that all the discussions prior to this latest work have revolved around what the NTSB .csv shows as the last altitude (and other parameters) readings when it would be quite obvious to anyone actually decoding the data that extra readings existed.

Thank you for your reply, "Pilgrum"

Originally posted by Pilgrum
As to the accuracy of a pressure altimeter: considering the resolution of the adjustment which is 0.01" Hg increments and 1" Hg representing near enough to 1000', we could expect an accuracy in the order of +/- 10' if the instrument was perfect in every way.

Not a bad answer, however I was looking at the accuracy of the reading,
not the 'resolution'.

Here are some FAA and FAR specifications for Pressure Altimeters:

rgl.faa.gov...$FILE/AC43-2B.pdf

In practise the accuracy would be somewhat worse than that.

Interesting. The manufacturers state that Pressure Altitude is more accurate
as you get closer to sea level. The FAA/FAR also has tighter tolerance
requirements for altitudes closer to sea level for certified altimeters used
in commerical aircraft.

Which source did you get your information from?

A radar altimeter would be an order of magnitude better for very low altitude measurements and immune to air pressure anomalies produced at extremely low level, high speed flight.

What 'anomalies' are you speaking of?

What does the speed of flight have to do with altitude pressure readings?

Thank you for answering these questions.

To Trebor:

Here is the FAA procedure for setting using PA. RADAR alt. is used on
approach below 1500 feet and landing the aircraft.

www.faa.gov...

FAA Tolerances:
adsb.tc.faa.gov...

Wow, look at that! From - 1000 feet to 10,000 feet ASL the Pressure Altimeter must
read within 20 feet of actual altitude! Is that HIGHLY INNACURATE?

Let's see the RADAR alt. are much more precise at +/- 1 foot, or 2%
(whichever is higher):

www.rockwellcollins.com...

In summary, it's very safe to say that a Pressure Altimeter is VERY
accurate.

So, the pressure alt. shown in the decode is STILL TOO HIGH TO HIT
THE PENTAGON and LIGHTPOLES.

P.S. TrueAmerican, I agree with your statement about serial numbers
and the authenticity of this data...however, we must analyse this information
and show the readers that sensor information proves the aircraft did not
hit the lightpoles.

Originally posted by Pilgrum
reply to post by turbofan

 

The reason I ask is that it appears that all the discussions prior to this latest work have revolved around what the NTSB .csv shows as the last altitude (and other parameters) readings when it would be quite obvious to anyone actually decoding the data that extra readings existed.

It appears that the last frames of data were only partial frames. In other words only some of the parameters were recorded, others are missing. The NTSB simply wasn't interested in that data perhaps because they were under a deadline to get info to the FBI. They along with everyone else already knew the outcome, so it wasn't necessary. Since then, that missing
data has been exploited by delusional fools and paranoid frauds along with those who apologize for terrorist's actions.

Why did PFT not admit or not realize they were there is a vey good question.

Also, if they were interest in the truth and whether or not this FDR belonged to the AA 77 aircraft, why did they not decode some of the additional data from previous flights to establish the authenticity of the box.

It's going to be difficult to claim the box is fake when all of that previous flight information is decoded and revealed. Some has been decoded already and there is no question of identity of the box.

Turbofan can argue the accuracy of a pressure altimeter versus a radar altimeter all day long as long as he gets instructions from his master.

How is he going to argue the longitudinal and lateral acceleration or more than -.5 G left and over - 1 G longitudinally (the maximum able to be recorded) in the last frame. The aircraft was not pulling up over the building, it hit something substantial to produce those readouts. I wonder what it was?

Originally posted by Pilgrum

The first decode of this data independant of NTSB was done in association with PFT members somewhat secretly ... 'readout2'

That particular decoding must have revealed the existance of the extra (incomplete) packet at the end of the raw file consisting of the altitude data we're discussing here now.

Yes, it's true members of P4T callobrated with ARINC and Boeing reps to
decode the .fdr file. The original decode "readout2" initially showed data
beyond the last full frame, however I do not know the details as to "what
was seen", or "valid".

A member of P4T by the name of "Undertow" has all the details if you would
like to contact him directly.

Have you acknowledged that data prior to W Stutts's decode and revelation of it and, if not, why?

I don't believe anyone has acknowledged this extra data; at least not to
my knowledge.

The reason it is not important (answer to your 'why') is because the
Pressure Altitude still shows too high to hit light poles.

The RADAR Alt. analysis along with the other supporting parameters also
shows trends of the aircraft being too high.

When you view the data parameters as a whole, and study the trends with
respect to the aircraft's position you can understand the behaviour of the
plane more clearly.

For instance, at 1 mile from the Pentagon wall, the plane was xxx feet
and moving xxx knots. Controls, accelerometers, etc. show changes
as the flight progresses.

If the RADAR altitude suddenly shows a change in altitude of 60 feet while
the accelerometers, or Pressure Altitude follows a trend, you can conclude
that the plane was passing over an object.

RADAR altimeters use RF [radio frequency] signals t determine height by
sending out frequency waves and measuring the speed of return once
boucing off an object.

Pressure altimeters use (local) atmospheric pressure to determine height
so flying over objects (buildings, trees, etc.) has no effect on the PA reading.

The reason I ask is that it appears that all the discussions prior to this latest work have revolved around what the NTSB .csv shows as the last altitude (and other parameters) readings when it would be quite obvious to anyone actually decoding the data that extra readings existed.

It's a valid question. Keep in mind the NTSB data has errors; specifically
in this topic altitude. The CSV altitude and animation altitudes do not
coincide throughout the flight. This is a problem and easily detected by
aviation professionals.

As it has been corrected and exposed by P4T, we have to ask why these
parameters differ if both files (animation and CSV) are derived from the
same .fdr file.

Some will say the animation is "a working copy". but they don't understand
the the PA at the beginning of the animation is fine, while the PA crossing
through 18,000 feet ASL does not match the CSV changes in the BARO COR column.

You are aware of the 'snap back' that I'm referring to?


Anyway, just remember:

Radar Altimeters are not used for the approach until they are in the
clearway zone approaching a runway on a Cat III ILS autoland. The
pressure altimeter will also correspond during this approach, unlike
at the Pentagon.

Originally posted by ReheatTurbofan can argue the accuracy of a pressure altimeter versus a radar altimeter all day long as long as he gets instructions from his master.

I don't have a master, but I'll take you up for a live radio/video debate
any time... in REAL time.

That way we can determine who needs their master around to help them
out.

Are you game? Mackey was too chicken, maybe you can man up?

How are you going to explain the difference in PA and RAD Alt. at the
end of the file?

Are you going to use bird strikes as your excuse?

Funny how that 80+ page thread at JREF is just a laugh after laugh.
Even moreso now that Mr. Stutt proved nothing got erased.

I hope your helpers are much better than those within that thread!

posted by TrueAmerican
The serial numbers were missing, as has been documented so many times here and elsewhere.

And to this day I have not seen one credible, or rational explanation for THAT.

posted by trebor451

The serial numbers were missing? How would you know that unless you have personally seen the FDR/CVR in question? Was there a news report/news release that specifically stated the "serial numbers were missing"?

Here is an alleged photo from the official US Department of Defense Pentagon 911 book of the alleged FDR planted on some guy's footprints. Perhaps you can see a serial number?

[atsimg]http://files.abovetopsecret.com/images/member/fdf9715396cf.jpg[/atsimg]

FDR from Pentagon 911 book

reply to post by SPreston

Here is an alleged photo from the official US Department of Defense Pentagon 911 book of the alleged FDR planted on some guy's footprints. Perhaps you can see a serial number?

Oh I love it!LOL that was a good one. You can clearly see that bone yard piece of wreckage was just planted on the pavement you can clearly see the wet foot prints underneath. LOL The FBI in their desperate attempts in staging evidences were very sloppy in their presentation. You just proved the FBI are lairs and the evidences is false.

reply to post by turbofan


Whops, you forgot to explain that brick wall suspended by a skyhook above the Pentagon lawn that caused the maximum longitudinal deceleration able to be recorded by the FDR in the last partial frame of data. Since you say the altitude was too high to hit anything, that brick wall had to have been suspended because that accelerometer readout indicates AA 77 hit something very significant!

There is no longer anything to debate and the FDR that you and your ilk have been trying exploit to support delusions has now bitten you in the posterior and proven you wrong. My condolences to you and your kind. When is the funeral?

Originally posted by turbofan
I don't have a master, but I'll take you up for a live radio/video debate
any time... in REAL time.

Really. Cap't Bob would take issue with that, no doubt.

Here's a question I don't expect an answer to.

Why are you even concerned about the FDR? Since it is all "faked", why even go to the trouble? It certainly can't be to demonstrate PfTs bona fides since their Camp Springs 1/P-56/NOTAMS/Gopher 06/SAMS at the Pentagon/Light Pole "Simulation" "analysis" belie any basic knowledge or understanding of these issues or how they should be addressed.

"We'll prove the FDR was recording the correct aircraft parameters as its stealth/invisible fly over was accomplished so the FDR could be pulled from the aircraft (before the aircraft was totally destroyed somewhere) so it could be planted in the building".

That's *almost* as good as all PfT's military people agreeing there were SAMs at the Pentagon.

Must be for entertainment value.

I don't see what you both are so worked up about? Have you even
studied the data trend that was uncovered?

How does this new information fit your 'theory'? Are you guys going
to toss away the 'missing seconds' BS that you cried about for all these
years?

If not, then explain how the last four seconds of RAD Alt. along with
all the other supporting parameters allows for hitting the poles?

How far were the poles from the "impact wall"?

How fast was the last recorded speed?

How high were the poles "clipped"?

I really don't see how you both feel so sure about this 'new find'. You
just take one parameter and forget about the rest?

I've been away on vacation for a week, and just getting to this new data.
Give me a couple of days and I'll be sure to update my latest post to
confirm the fdr file does not support the OGCT.

Originally posted by turbofan
I don't see what you both are so worked up about? Have you even
studied the data trend that was uncovered?

I'll ask this again and maybe at some point it'll be answered.

Why are you even concerned about the FDR? Since it is all "faked", why even go to the trouble? It certainly can't be to demonstrate PfTs bona fides since their Camp Springs 1/P-56/NOTAMS/Gopher 06/SAMS at the Pentagon/Light Pole "Simulation" "analysis" belie any basic knowledge or understanding of these issues or how they should be addressed.

This really is a waste of time, since turbo likes to duck the data and its trends and assert specifications instead. Fact, PA is given as between 42-44 when the plane is on the ground at Dulles. Fact, the elevation of Dulles ranges from 270 to 290. Corrected (according to P4T) for local pressure, the PA is 342-344 feet under ideal circumstances (stationary). And this is for the take-off of AAL77.

Looking at PA on the ground at Dulles at the end of Flight #11 (as recorded in the FDR), the altitude is 120 - 121 feet! Now which is it turbo? Is the altitude at landing correct, or is it the PA at take-off?

So yes, I repeat, PA is highly inaccurate for these purposes. Or at least I call a difference of 80 feet a significant difference.

[edit on 28-10-2009 by 911files]

reply to post by turbofan


Hello Turbofan,

Thank you for your posts. I am not familiar with the reliability of the equipment you gentlemen are speak of. However, I have been reading posts here and several other forums that show the FDR does not really support the flyover theory. Warren Stutt seems to have done quite a bit of work. Reading his posts at PFT & JREF, he appears to be quite neutral regarding where he stands on the 911 issues.

So, I guess my question to you is; Do you still believe that the FDR supports the flyover theory?

Thank you in advance for your cooperation!

Dr. P

reply to post by 911files


While TF chews on that one....haven't seen this brought up yet:

Somewhere, somewhen, the P4T crowd tried to point to some evidence of lateral drift in the IRS position data, during the takeoff from IAD. Does anyone remember that particular red herring? I think they were actually attempting to use the fact that IRS drift occurs, in each individual unit, to "prove" their 'north-of-citgo' hypothesis.

Of course, those of us who have actually trained on, and flown the airplanes in question know more about how the systems work.

What I don't know, since there was no reason for me to have this knowledge, is whether the SSFDR records the Lat/Long data for all three IRSs, or just the left (Captain's). Maybe someone has this answer?

A quick review, for those who may not know how it works:

You initialize all three IRS platforms at your 'known position' (whether the gate, or a hardstand) and after about ten minutes (usually less) they are fully aligned, and in 'NAV' mode. They continue to be independent of each other, but the FMC software looks at what each unit 'thinks' is its position, and averages it to make the "mix' position, which is what the FMC references to. This "mix' position exists only in the FMC computations, and is displayed on your CDU screen --- INIT REF page. Depends, it can be found on other pages, especially in the Pegasus versions of the software. This 'mix' position is not recorded on the SSFDR.

Typical airline SOP (and I assume this was the procedure at AAL) is to line up for takeoff, spool the engines to stabilize them at about 40-50% N1, then TOGA to engage the autothrottles. The takeoff runway is in the FMC database, as part of your pre-departure prep...so the software is designed to "update" your position to all three IRSs when TOGA is pushed...since the database knows the Lat/Long coordinates of each runway threshold area.

This is fairly common in just about every modern FMC-equipped passenger jet today...especially in the Boeings (and I cannot speak to Airbus, have no experience in them, other than on the jumpseat --- rarely). But, I would assume the Airbus avionics and programming have similar traits.


All of the foregoing was to explain why the minor drift seen as the airplane taxied out for takeoff can't be used to "prove" anything about the actual lateral positional track over the ground in the final seconds. The IRSs are continually updating...when they're in AUTO...IF the hijackers selected VOR on the mode selector for the EHSI display, then the auto-update feature is disabled. Coupled with the maneuvering and higher-than-normal speeds at low altitude, the accuracy of the IRS position information cannot be used except in the broadest sense.


Much hay has been made of the DME from the DCA VOR/DME that is located at Washington national Airport.

Again...we've determined that there is a level of accuracy, per the manufacturer, of +/- 0.1 mile. So, a reading of, say, 1.5NM means that it could be anywhere from 1.4NM to 1.6NM. A NM is 6,067 feet in length, so one-tenth is 607 (rounded) feet. DME is not all that accurate, for this purpose, because it gives us a lot of margin. Locate the DCA VOR/DME, then draw three arcs, at the 1.5NM point, and the accuracy tolerance range....and try to have those arcs intersect the ground track of the airplane on the final approach run at the Pentagon.

There's not enough information, yet, just from that...ing information (True heading, in this case, since you're using a map that is plotted according to True North...eh....It's getting too complicated, I think I hear eyelids flapping....)