So When Do We Find Out, Where it was prior to 9/11 Options

[Aldo Marquis CIT]

Any word on that?

[UnderTow]

"There were no problems or delays in loading the data and seeing that the file is good.
About 11-13 flights were evident just by displaying airspeed in graph for the length of the file."

"We tried to export CSV the entire file for all params but gave up after a long time. We estimated the resulting CSV would have been huge and taken hours to process. You wouldn't even be able to begin to look at it unless you put it in a database. It would have been great to have, but oh well."

That said, what we have (if you look at even the limited file) is 'some' previous FDR On (or engines on) time only at the Dulles facility. While I did look at the full data in application, it was only for basic airspeed altitude stuff. We may get another chance in the future to see more.

[wstutt]

Any word on that?

Hi Aldo,

I have checked the coordinates in the uncompressed portions of the compressed AAL77 FDR file up to the final flight and found that they match with what I believe to be major commercial airports.

Up to 4 seconds of uncompressed data is generated when the FDR is starts up which I believe happens when the engines are started, so all the uncompressed portions that I can decode are at airports rather than during flights.

Unfortunately there is not enough data for me to get dates, but if you like I can post details of the coordinates and airports.

Warren

[rob balsamo]

Yes, please post it... (IMG:http://pilotsfor911truth.org/forum/style_emoticons/default/smile.gif)

Also, if you can post a detailed explanation of how you were able to decode it and/or post the program?

Thanks!

[wstutt]

Yes, please post it... (IMG:http://pilotsfor911truth.org/forum/style_emoticons/default/smile.gif)

Also, if you can post a detailed explanation of how you were able to decode it and/or post the program?

Thanks!

Hi Rob,

Since you're interested, I will post the program on my web site, however I'll modify it first to at least get rid of the hard coded folder names that are set to work for my computer. I'll add a few comments as well. At the moment the program only decodes the radio height and latitude/longitude coordinates.

I can also decode the following parameters:
FRAME COUNTER
SYNC WORD

I may also be able to decode the following parameters, thanks to the 573b.Short.txt file on UnderTow's web site:
VERTICAL ACCELERATION
ALTITUDE (1013.25mB)
LONGITUDINAL ACCEL
LATERAL ACCELERATION
GROUND PROX WARNING
COMPUTED AIRSPEED
GMT SECONDS
GMT HOURS
GMT MINUTES

Given that the uncompressed portions that I am able to decode are recorded when the plane is at the airport, these other parameters may not be of interest.

Do you think I should decode them anyway?

I'll hold off on positing the file so that if I add extra parameters to the program, the file matches up with what the program produces.

As to how I was able to decode the data, this post and figure 4.2-2 of this document were especially helpful.

I found that the words in the figure are 16 bit words stored Least Significant Byte first and that the Hamming Code & Page Parity occupies the last 11 bits of each page. Within each 16 bit word, the most significant bit is the first bit in the bit stream. Some pages are blank consisting entirely of 0xFFFF words and need to be skipped. After the text header of the file which occupies the first 176 bytes, there is a 32K word block from Flight Data Stream 0 followed by a 32K word block from Flight Data Stream 1 and then another 32K word block from Flight Data Stream 0 and so on. The recorded data starts at offset 0x3C00AA in the file and goes on to the end of the file before wrapping around to the beginning.

The uncompressed data can be built up by taking the first bit in the bit stream as the least significant bit of a 12 bit word and then building up subframes of 256 x 12 bit words each. Uncompressed subframes can be recognised by the sync word which is the first word of each subframe. The valid sync word values are 583, 1464, 2631 and 3512 as shown in Readout2.

My program takes two consecutive sync words in the correct positions to be an indication of uncompressed data. This method is not fool proof however and for some parts of the file it tries to decode compressed data as if it was uncompressed.

Warren.

[rob balsamo]

Thanks Warren,

I think UT would better understand the details of the decode process. However, please also be careful in posting the program as you may be asked to take it down since decode programs are proprietary and i have a feeling on a "need-to-know". But i suppose we can argue that we "need-to-know", (IMG:http://pilotsfor911truth.org/forum/style_emoticons/default/wink.gif)

No one has emailed me about your other UA93 program asking for it to be removed. Anyone contact you?

Also dont be surprised if it is argued that since the FDR data is already in question, and that no one personally knows who you are, that many may not take these decodes too seriously (although if it supports the govt story, im sure the govt loyalists will lap it up, regardless of source). Unfortunately, P4T wont be able to use any of it for publishing purposes as we havent done with the initial raw file decode except on this forum.

Thanks again for all your hard work.

[wstutt]

Thanks Warren,

I think UT would better understand the details of the decode process. However, please also be careful in posting the program as you may be asked to take it down since decode programs are proprietary and i have a feeling on a "need-to-know". But i suppose we can argue that we "need-to-know", (IMG:http://pilotsfor911truth.org/forum/style_emoticons/default/wink.gif)

No one has emailed me about your other UA93 program asking for it to be removed. Anyone contact you?

Hi Rob,

I definitely agree that we "need-to-know". No one has contacted me about removing my UAL93 FDR decoder program. I'll continue to provide the program as long as I can and as long as I believe there may be interest in it. No one seems to have asked for what I presume is proprietary information in the links I mentioned in my earlier post to be removed either since they're still there.

Also don't be surprised if it is argued that since the FDR data is already in question, and that no one personally knows who you are, that many may not take these decodes too seriously (although if it supports the govt story, im sure the govt loyalists will lap it up, regardless of source). Unfortunately, P4T wont be able to use any of it for publishing purposes as we havent done with the initial raw file decode except on this forum.

I'm happy to let the program stand on its own merit. One reason I provided the source is so that if anyone regardless of what they believe about 9/11, thinks that the program incorrectly decodes the data, they can email feedback to me using the links on my web site.

I understand that people may not wish to use data that does not come from an official source and that I have not used complete official documentation to create the program. That is their choice.

Thanks again for all your hard work.

Your welcome. Thanks for the work you are doing to raise the important issues concerning the data provided by the NTSB. I would not know about them otherwise.

Would you like the extra parameters to be decoded that I mentioned in my earlier post?

Warren.

[rob balsamo]

Sure, the more information you provide, the better. Thanks again..

[wstutt]

Sure, the more information you provide, the better. Thanks again..

Thanks Rob, I'll get to work on it. I'll probably start a new topic when the program is ready.

Warren.

[wstutt]

After the text header of the file which occupies the first 176 bytes,

Sorry, that should have been 170 not 176.

[wstutt]

...

Also dont be surprised if it is argued that since the FDR data is already in question, ...

Hi Rob,

When you say the FDR data is already in question, do you mean the compressed FDR file, the NTSB CSV files, Readout2 from UnderTow or something else?

Thanks,
Warren.

[rob balsamo]

The raw FDR file is in question due to time stamps, the fact it was never prepared for public distribution, and the fact the NTSB and several FDR Companies say were arent supposed to have it. The only thing we can argue with Govt Agencies are the files prepared, plotted and provided by the NTSB, which are the original csv file and animation. The reason we cannot use the raw FDR file for anything is because the first question asked by govt agencies will be, who decoded it for you? The person who helped us decode the raw file is from an FDR Company and will readily lose his job if we give a name. I suppose we could now probably use your name for the decode, but you would have to be present during any questioning, if hopefully one day, it gets to that point.

[wstutt]

Thanks Rob,

I hadn't thought of that. I would like to see another investigation as well. Perhaps the investigation could subpoena the raw FDR data along with the complete technical documentation required to decode it and that would settle questions over the FDR data.

In the mean time I have completed work on my program to decode the small fraction of the FDR file that is uncompressed. I plan to upload it along with the source and some output files to my web site as soon as I can get my web hosting provider to get the C# one click installation process working (the same as what I used for the UAL93 FDR Decoder)

I want to get this resolved shortly for two reasons, since in addition to providing these programs to help researchers such as yourselves, I am also using them as examples for potential employers of C# programming that I have done. This is because I have no commercial experience in programming in C# although I have several years commercial experience programming in other languages.

I'll start a new topic as soon as I get everything uploaded.

Warren.

[rob balsamo]

Thanks Warren,

Unfortunately, we probably wont be using most of it, if any at all, due to the fact we cant argue it. But like i said, the more information the better and im sure the govt loyalists will lap it up if any part supports the govt story, regardless of source.

Our main concern right now is the information prepared, plotted and provided by the NTSB/FBI which doesnt support the govt story.

[wstutt]

Thanks Rob,

I believe I understand what you are saying is that you need to use the strongest and least disputable evidence available that would stand up in court and that would be the official NTSB/FBI supplied CSV files, plots and reports.

I've got no problem with that.

I'd still be working on decoding the FDR data even if it was only for me.

Warren.

[rob balsamo]

(IMG:http://pilotsfor911truth.org/forum/style_emoticons/default/thumbsup.gif)


and sorry for the typo in your name.. i'll fix it... (IMG:http://pilotsfor911truth.org/forum/style_emoticons/default/wink.gif)