AA77 FDR Data, Explained

[Anti-sophist]

Originally Posted by Qubit

Don't forget VLSI concepts:
- Wiring and Interconnect: Elmore Delay, capacitance (fringing, interwire, cross-talk), low-k dielectrics, reduced swing, resistance, electromigration, inductance
- Gates: nmos, pmos, transient response, propagation delay, sizing, fan-in/out, subthreshold leakage
- combinational logic: logical effort, ratioed logic, pseudo-nmos, DCVSL, pass-transistors
- dynamic logic: charge sharing, backgate coupling, domino logic, differential domino logic
- sequential logic: latches, (positive/negative) edge triggered registers, C2MOS, TSPC, Schmitt Trigger, VCO

Etc, etc...just for starters

Sigh these are digital systems, and you haven't even built a NAND get yet, let alone a multiplexer or an ALU.... Better get to work. This document is gonna be 1000 pages before it's done.

[Skibum]

Quote:

This document is gonna be 1000 pages before it's done.

Unfortunatley, it will be 999 and 15/16ths pages past the attention span of the CTs.

[gumboot]

Originally Posted by Skibum

Unfortunatley, it will be 999 and 15/16ths pages past the attention span of the CTs.

And that's only if the cover has a nice picture on it...

-Gumboot

[UnderTow]

Originally Posted by Anti-sophist

You and JDX's dopey analysis is based on a misintrepretation of the CSV file.. that dopey intrepretation DOES assume bitrate and phase, inadvertently, by consequence of the way you are reading the file.

Ah see. Now we are getting somewhere. Please point out which dopey analysis you are referring to?

Also, please confirm or dismiss whether you believe every single crash investigation which uses FDR read outs also contains these error which you have designed. Because your paper could be describing any FDR and Tabular plot from any airplane right? Do you believe all investigations which use downloaded data from an FDR and make a table and graph out of it are flawed?

Originally Posted by AntiS

My initial intent was to properly analyze the data and debunk the variety of dopey conspiracy theories that abounded.

You never got to the 1st part, instead you waxxed on with your own assumptions and theories of errors. And the 2nd part is also incomlete becuase you have yet to specify which dopey theory you have debunked, other then to theorize how ALL fdr readouts beyond the raw file are flawed hopelessly and forensicly worthless.

You should dress up your paper and send it to the Boeing, L3 et all becuase I'm sure they could use the help in fixing these erorrs you have created.

Can you show one example from any FDR analysis of the massive errors you have given in your paper? After all, you "gathered up all the publically available flight-data-recorder information" right.(?)

I don't think your an idiot and I never said that. I think your paper is mush.

I'm glad we have been able to have this talk, but your intent seems to be more about debunking dopey stuff to gain Randi high-fives instead of actually examing the data. Regardless, after me and other "poor software engineers" get done doing another read-out from the raw file, I'll be sure to include you in the peer-review.

[Anti-sophist]

Originally Posted by UnderTow

Also, please confirm or dismiss whether you believe every single crash investigation which uses FDR read outs also contains these error which you have designed.

It's been answered. Repeatedly. Just to clarify, I don't think this investigation even suffered from these errors. My claims apply solely to the CSV file, which is not what the investigation is based on. The real invesitgation used the real data. You aren't. These errors apply solely to your amateur investigation based on incomplete data.

Quote:

Because your paper could be describing any FDR and Tabular plot from any airplane right?

Any derived CSV file in the format of the tabular CSV file from flight 77, yes. Luckily, real engineers use the real data.

Quote:

Do you believe all investigations which use downloaded data from an FDR and make a table and graph out of it are flawed?

Of course not. I believe that basing forensic analysis on data meant to be plotted, however, is flawed. Luckily no actual engineer would ever do that. They'd download the data in its raw form, and use that.

Quote:

And the 2nd part is also incomlete becuase you have yet to specify which dopey theory you have debunked

All forsenic analysis of the FDR data based on the CVS file, that I've seen form CTers, has flaws that are at least, in part, explained by this paper. I admit that this paper does not completely debunk all parts of all analysis (ie, it does not explain instrument error from an altimeter).

Quote:

other then to theorize how ALL fdr readouts beyond the raw file are flawed hopelessly and forensicly worthless.

Lie.

Quote:

You should dress up your paper and send it to the Boeing, L3 et all becuase I'm sure they could use the help in fixing these erorrs you have created.

Same, tired, strawman that you repeat every single post and I've answered 100 times. When are you going to stop repeating this tripe? When are you going to even comprehend what I'm saying?

Quote:

Can you show one example from any FDR analysis of the massive errors you have given in your paper?

Real FDR analysis doesn't have these errors. Why? Actual engineers can correct this error given the FDR data. You can't for two reasons. The first is that you don't have the full FDR data. I'll let you guess at the second.


Are you going to stop claiming that I am saying FDRs are flawed? Nope.
Are you going to stop claiming that I have found errors in actual FDR data? Nope.
Are you ever going to understand that the CVS file isn't the raw FDR data? Nope.
Are you ever going to understand these errors exist solely because the CVS file is not raw FDR data? Nope.
Are you ever going to understand that engineers aren't using the CVS file to do the actual analysis? Nope.
Are you ever going to understand the purpose of the CVS file wasn't to do actual analysis? Nope.
Are you ever going to explain the footnotes that clearly show I am right? Nope.

What are you going to do? Keep repeating the same stupid strawmen, forever? Showing you are not only completely incapable of understanding the science in the paper, but it's intent, as well? Continue to keep claiming that I am saying things that I am clearly not saying? Forever?

As always, I am open to correction.

[UnderTow]

Therefore you are saying that the NTSB engineer who created this CSV file did not know what she was doing and did not correct for these errors. Therefore any other report this engineer has done is also flawed becuase they took the raw file, converted it to engineering units, made a table out of it, and created an assumption like this:

Originally Posted by NTSB

The SSFDR data indicated that at 1031:37 DFDR elapsed time, while the airplane
was descending through a pressure altitude of 5,984 feet, maintaining a magnetic heading
of 139 degrees, and flying at an indicated airspeed of 191.47 knots, roll attitude values
consistent with a left wing down motion were observed. Engine data at this time indicated
N1 values to be 30.3% and 31.4% for the left and right engine, respectively.

Which is represented in one Row in a Table like this:

Originally Posted by NTSB

10:31:37 5984 191.47 139.53

This is not AA77.

Again, a Table is based on Real data. They use the Table to investigate the event.

Originally Posted by AntiS

I believe that basing forensic analysis on data meant to be plotted, however, is flawed. Luckily no actual engineer would ever do that. They'd download the data in its raw form, and use that.

"Data meant to be plotted". You mean that taking a raw FDR data file, converting it to human readable form (table or graph) an using that table or graph is "flawed"?

[Anti-sophist]

Originally Posted by UnderTow

Therefore you are saying that the NTSB engineer who created this CSV file did not know what she was doing and did not correct for these errors.

Lie.

Quote:

This is not AA77.

Source.

Quote:

Again, a Table is based on Real data. They use the Table to investigate the event.

Not the CSV file from AA77, they don't. This is so wrong it's funny.

Quote:

"Data meant to be plotted". You mean that taking a raw FDR data file, converting it to human readable form (table or graph) an using that table or graph is "flawed"?

No, the CSV file is more than "converted to human readable" form. It has been processed beyond that. A tabluar version of the FDR, just "converted to human readable form" does not look like that CSV file from AA77. Try again. This has been explained to you, at least twice, and will not be repeated a third time.


PS. Still waiting for your explainations of the footnotes.

[UnderTow]

What are you right about?
Which CT analysis are you referring to?

How does this NTSB fdr-sourced table differ from any other table in any other instance?

The NTSB investigation used the real data.
THE CSV file made by the NTSB used the real data.
The Graph made by the NTSB used the real data.


Unfortunately, you can no longer edit your orginial post, so I don't know how your going to correct that.

[Anti-sophist]

Originally Posted by UnderTow

What are you right about?

Huh? Everything?

Quote:

Which CT analysis are you referring to?

Already been answered.

Quote:

How does this NTSB fdr-sourced table differ from any other table in any other instance?

Already been answered.

Quote:

The NTSB investigation used the real data.
THE CSV file made by the NTSB used the real data.
The Graph made by the NTSB used the real data.

All true. The CSV file, however, is not EQUAL to the real data. It is not just the REAL data presented in a different form. It is _based_ on the real data, but some information has been lost in the processing.

This has been explained, to you, repeatedly.

Quote:

Unfortunately, you can no longer edit your orginial post, so I don't know how your going to correct that.

Correct what? Why would I edit my post? All I need to do is copy/paste the same answers to the same stupid questions, over and over and over.

PS. Still waiting for your explaination of the footnote.

[UnderTow]

Source?? HAha..
"gathered all publicly available information"
I guess it should be in one of your files then.

Quote:a Table is based on Real data. They use the Table to investigate the event.

"Not the CSV file from AA77, they don't."
How can you prove this? What make this NTSB CSV Table different from any other Table?

[Anti-sophist]

Originally Posted by UnderTow

Source?? HAha..
"gathered all publicly available information"
I guess it should be in one of your files then.

You claimed it was not from AA77. I didn't download every single piece of information ever in the history of the universe.

Source it, or go away. Are you scared of giving me the full data? Why?

Quote:

What make this NTSB CSV Table different from any other Table?

This has been answered at least twice, and will not be repeated. The short answer is that the CSV file _cannot_ be raw FDR data presented in tabular form. The CSV file is _not_ what raw, tabular, FDR data looks like. In order for raw FDR data to be put into the CSV format, it would need to be processed. The details on why this is so have been addressed, with you, repeatedly, in this thread.

PS. I must have missed your explaination of the footnote... did deal with it yet?

[UnderTow]

Quote:

Huh? Everything?

Only in your mind

Quote:

Already been answered.

Lie

Quote:

Already been answered.

Lie

wow, that's nice an easy just to type 'lie' and forget about it

Quote:

All true. The CSV file, however, is not EQUAL to the real data. It is not just the REAL data presented in a different form. It is _based_ on the real data, but some information has been lost in the processing.

Oh right. In other words at the 46'th second, you would theorize that the Speed parameter could be from 2 seconds ago (or in the future) and not in sync with any other parameter within the same second. That the NTSB doesn't know how to use a frame descriptor to compute the raw parameter, that L3 doesn't know the 573/717 Requirments in order to keep all this data in sync, and the Boeing doesn't know who to program a 429 bus to calculate for the delay from the instrustment to the FDAU.

Becuase you have designed all these systems by yourself already and if it wasn't for the "poor software engineer" messing everything up, then all these parameters in tables wouldn't be so messed up.

[Matthew Best]

Reading that last UnderTow post suddenly brought the phrase "Look at this collapse" to mind for some reason.

[DavidJames]

Originally Posted by Matthew Best

Reading that last UnderTow post suddenly brought the phrase "Look at this collapse" to mind for some reason.

It seems clear to me UT doesn't understand what's "below" the csv file. He's missed AS point completely, whether it's an honest mistake or not, he doesn't get it.

[mcMike]

Anti-Sophist could you please explain.

I am trying to understand more deeply this FDR-issue. Here's couple of things that confuses me.

1. Why is the flight-path in NTSB-animation in wrong position in final approach? I checked the CSV-file and didn't find any "GPS-coords" as I expected so I assume that the flight-path is reconstructed with external radar-data or via inertia calculation? Or whats the deal?

2. What is the thing with the heading issue? About last 20 seconds are indicating heading to 68-70 degrees. The last 10 seconds 69.6-70 degrees. The official flightpole-path is about 61 degrees. The "eyewitness-path" is over 80-degrees. So the heading in FDR-data seems to be in the middle of those. Am I missing something or how to interrept the heading? With 70-degrees it seems to be impossible to hit the poles.

I used GoogleEarth and overlaid image with both paths into it and drew some lines in Photoshop to determine the headings. Path is from 911-strike, the image name flight_path.jpg (can't post links)

Thanks.

[Anti-sophist]

Originally Posted by UnderTow

Oh right. In other words at the 46'th second, you would theorize that the Speed parameter could be from 2 seconds ago (or in the future) and not in sync with any other parameter within the same second.

Fairly true, except for the ridiculous bolded part. Again, you'd need to define "in sync". All measurements have some error. Saying two things are "in-sync" implies within some error tolerance, they are sync'd.

Quote:

That the NTSB doesn't know how to use a frame descriptor to compute the raw parameter, that L3 doesn't know the 573/717 Requirments in order to keep all this data in sync, and the Boeing doesn't know who to program a 429 bus to calculate for the delay from the instrustment to the FDAU.

Of course they know how. The CSV file doesn't contain this information. The real engineers know how, and do, when they do real analysis.

Again, this is for plotting data. Listing every single data point and it's associated measured time is unnecessary to produce plots at the resolution required. The plot doesn't require the full precision, so the CSV file isn't in the full precision.

Quote:

Becuase you have designed all these systems by yourself already and if it wasn't for the "poor software engineer" messing everything up, then all these parameters in tables wouldn't be so messed up.

Wrong, again. It has to do with intent. Generating data within acceptable error tolerances to do the plots attached to the NTSB report is not the same as generating data to base forensic analysis of the final 2 seconds of flight 77.

Those are different problems and require different amounts of error tolerance. The CSV was designed to solve one, not both.

PS. The mysterious footnote that confirms everything I've said remains.. unexplained. I should start counting how many times I've asked you to explain it.

[Anti-sophist]

Originally Posted by mcMike

I am trying to understand more deeply this FDR-issue. Here's couple of things that confuses me.

1. Why is the flight-path in NTSB-animation in wrong position in final approach? I checked the CSV-file and didn't find any "GPS-coords" as I expected so I assume that the flight-path is reconstructed with external radar-data or via inertia calculation? Or whats the deal?

2. What is the thing with the heading issue? About last 20 seconds are indicating heading to 68-70 degrees. The last 10 seconds 69.6-70 degrees. The official flightpole-path is about 61 degrees. The "eyewitness-path" is over 80-degrees. So the heading in FDR-data seems to be in the middle of those. Am I missing something or how to interrept the heading? With 70-degrees it seems to be impossible to hit the poles.

First, let me reiterate an important point. This paper and most of the issues discussed in it was created before this "new" analysis from JDX came into being. I haven't looked, in depth, at the heading issues, like I have the altitutude, acceleration, and roll angles.

My initial reaction is that to look at this, in detail, is a waste of my time, because none of the CTers seem to have any intellectual honesty, to begin with. JDX and UndeTow continously misrepresent my position and argue with claims I am not making. They've failed every single attempt at even comprehending my position, let alone attacking it.

That being said, I'm willing to look at the heading thing in more detail, but my tolerance for this strawman and intellectually dishonest gibberish is growing short.


I have two questions, first, that I'd like you to answer:

Quote:

68-70 degrees.
69.6-70 degrees.
The official flightpole-path is about 61 degrees.
The "eyewitness-path" is over 80-degrees.

Are these all relative to north? True north or magnetic north?

[mcMike]

Originally Posted by Anti-sophist

I have two questions, first, that I'd like you to answer:
Are these all relative to north? True north or magnetic north?

Good point. Didn't realise that at all.
The heading from FDR is seems to be magnetic (MAG HEADING CAPT (DEG)).
Unfortunately I don't know which is the "North" in GoogleEarth. Anyone?

What is the difference between these two? In degrees?

And what about the explanation for flight-path inaccuracy in animation?

IMHO, looking this into detail is definetelly not waste of your time. And just for the record. I am not "attacking you". We're on the same side. I'm just looking for an explanation for myself since I want to understand the issue here.

ps. I sent the imageshack filelink via PM to you.

[Anti-sophist]

Originally Posted by mcMike

Good point. Didn't realise that at all.
The heading from FDR is seems to be magnetic (MAG HEADING CAPT (DEG)).
Unfortunately I don't know which is the "North" in GoogleEarth. Anyone?

I am almost positive google is "true" north.

Quote:

What is the difference between these two? In degrees?

In DC, according to http://www.ngdc.noaa.gov/seg/geomag/...F0EA567DAF2F53 it is 11 degrees (EDIT: to the west, which makes it line up almost perfectly).

That's 2 minutes of searching, so don't take my word for it.

Quote:

And what about the explanation for flight-path inaccuracy in animation?
ps. I sent the imageshack filelink via PM to you.

I'm at work. I'll get in more depth when I'm home. We also need to correct heading for wind to get the bearing.

[mcMike]

Originally Posted by Anti-sophist

I am almost positive google is "true" north.
it is 11 degrees.
I'm at work. I'll get in more depth when I'm home. We also need to correct heading for wind to get the bearing.

Thanks. So difference between true and magnetic north alone and maybe windspeed / direction can explain the heading. (if the differences are in correct direction )

You really should take a look of this in detail because that could debunk the "eyewitness-path"-theory at once. If we can trust the heading from FDR it is highly unlikely that the plane flew the "wrong-path" in 20-degree yaw.

I believe there is +-1 degree accuracy in the image I posted to you. I tried to be very precise with layer-aligment and rotation.

[Anti-sophist]

My suspicion is that at 500mph, the wind isn't going to cause much of an error between heading and bearing, but for an accurate estimate of it, you'd need to at least prove it's safe to ignore.

[CurtC]

Google Earth uses bearings relative to true North. The difference at Washington, DC, between true and magnetic North is close to 10.75 degrees, so that a flight path of 70 degrees relative to magnetic North would be 59.25 degrees relative to true.

What "eyewitness-path" are you referring to? The eyewitnesses saw the plane hit the light poles, right? You're not talking about the Citgo employee that the Loosers talked to five years later, are you?

[Darth Rotor]

Originally Posted by Anti-sophist

I am almost positive google is "true" north.

You are correct.

Aviation cocpit display systems typically present heading in magnetic degrees. Various navigation systems can convert to "True North" and often do to align with the WGS 84 model's True North used on charts. GPS nav systems typically calculate display True Course and Mag Heading and course, depending on the menu system used. The conversion (arithmetic) is simple addition or subtraction done based on the Magnetic Variation referenced to local isogonic lines.

On most aeronautical charts, a compass rose is included to allow a conversion from course (true) to course (magnetic). This allows you to plot and plan a no wind course for your flight plan. Once airborne, you crab into a given cross wind to stay on course. This makes for a heading (again, in Magnetic) that will vary from the course depending both on compass deviation and magnetic variation.

Aircraft gyrocompasses, and standby compasses, are magnetic compasses. There are inertial nav systems that use other baselines. I imagine the F-15's does. When various nav ystems fail or malfunction, the magnetic based compass system still provides a reliable magnetic course (in latitudes below the arctic circle) and heading display.

A sound reason for manufactureres to keep using this convention is that the Earth is not actually spherical. As good as WGS 84 is as a model, the actual local ground track needs to account for local deviations from "the perfect sphere" to ensure hazard and obstacle avoidance is practically maintainable.

GPS does have the potential to allow for everything to be in "true" at some point in the future. At this point, I am not sure if that is such a good idea.

DR

[Darth Rotor]

Originally Posted by Anti-sophist

My suspicion is that at 500mph, the wind isn't going to cause much of an error between heading and bearing, but for an accurate estimate of it, you'd need to at least prove it's safe to ignore.

I tend to agree, as the posted Wx report some weeks back didn't show a significant wind speed.

A note of caution. The pilot appears to have disconnected/deselected the auto pilot function some miles before his final descent/attack, so heading is likely to have varied a degree or two, even on final, as he continually corrected to keep his nose pointed to an intercept to his target. Target drift and correction tends to be larger among novice pilots and low time in model pilots than among experienced airline captains for a given model.

DR

[Anti-sophist]

The hard part of this "wrong heading" debunking is going to be convincing CTers why the animation is wrong. They all seem to think you stick the raw FDR data into a magic machine, and it spits out all the answers in the universe. And since we are claiming the magic machine is broken, why do we think we know more than Boeing, the FAA, and L3.

[UnderTow]

Well golly gee you smart people. Let's see if we can step through it here.
Data(parameters) from around the plane arrives at the FDAU.
The FDAU is programmed with the specific details of each different parameter(data).
The FDAU syncs all this data within tolernance per type and relative time to either it's inernal or external clock which also is the Time Parameter(data) (all data is now sync'd to 'measured time' within spec tolerance) and assembles the frame.
The FDAU sends this assembly of data using the 717 frame to storage(FDR).

Now let's quote the actually specification from ARINC:
Parameters are grouped into frames according to their sample rates.
Each frame is built at its specified rate. When each frame is due, all of the member parameters are sampled, converted as necessary, and packed into the frame.
The frame is identified with a frame label and a time stamp and sent to the recorder.
Once the frame is time stamped, the amount of time taken to record it is of less concern since the time of occurrence for the data in the frame is clearly indicated by the frame time stamp.

A Frame is a time-tagged grouping of recorded parameters. Since the Frame Time Tag applies to all parameters in the frame, the amount of time that elapses while acquiring the parameters should be minimized.

Now again, your going to repeat yourself and say we can't read the raw file so the CVS file is flawed by your theory such as:
"If the data was measured at 0.3s, and recorded at 0.75s, our poor software engineer who is decoding it later will think it was measured at 0.75s."

Why would he think that? Well, you continue in your paper:
"This problem is generally solved by reserving space in the data-stream for time-stamps of the data. In other words, word 3 might be for the computed airspeed, and word 4 might be for the time-stamp that the computed airspeed was measured."

At this point, are you assuming that each parameter would have it's own word to record it's own time of measurement? Thus doubling the entire size of the frame (or halfing the available space) and removign a primary function of the FDAU.
Or do you believe the actual word used to record the Time is not relative to the other parameters in the same frame?

I know, you still want to use that footnote from my graphic to adjust the parameters time stamps. But let's look at an example of why that footnote is important and also show a demostration of proper sub-second analysis:
~~~~~~~~~~
FDR Stoppage Time

Analysis of the last seconds of recorded FDR data indicate that power to the FDAU was interrupted. The FDR lost synchronization after word 54 of subframe 3, which corresponds to a time of approximately 0125:39.8. Two words containing 1s and 0s were then recorded, followed by 27 words, most of which contained only 0s. The FDR then regained synchronization, repeating subframe 3, although with updated values. The frame counter was incremented by one, and the recording continued for another partial subframe of 22 valid words (duration of 22/64 of a second), after which the recorder stopped. It was determined that a brief power interruption to the FDAU had occurred between word 54 and the pattern of 0s. When the FDR loses signal input from the FDAU, it continues to record for up to two words (duration of 2/64 of a second), based on tests carried out by the FDR manufacturer.

The FDR will coast through a power outage of up to 400 milliseconds, during which time no recording will take place, even though the recorder is still up and running. When power was restored, a FDAU re-boot was initiated, as indicated by the 27 words of 0s (a duration of 27/64 of a second). The re-boot was considered to be a warm start, in that 0s were recorded without a resetting of the frame counter. A warm start re-boot implies a power interruption of anywhere between 10 and 400 milliseconds. The actual duration of the power interruption was not determined. However, it was most likely at least 2/64 of a second long, in order to have recorded the two non-zero words, representing a loss of FDAU signal. Therefore, following the loss of the FDAU signal, there was no recording of data for a maximum period of up to 0.37 seconds (0.4 minus 2/64).

Based on the pattern of the re-boot and the possible duration of the power interruption, the FDR stopped recording between 1.8 and 2.2 seconds after the FDAU power interruption (see above). The time of FDR stoppage would therefore be somewhere between 0125:41.6 and 0125:42.0.
~~~~~~~~~~~

Amazing good work that is there. Now I know you're going to blah blah gibberish about CSV is not FDR data, but you have yet to account for all the standards (which occur prior the CSV and eliminate these errors), plus the NTSB's (or anyone's ie FlightScape) read out software which is explicitly designed to read raw files and not screw them up when plotting them to a table or graph.

But jolly oh, you paper is a flawless victory and you should be proud of your work. I'm sure it will show up at some real Science forum where your peers will quickly award you with numerous Randi Accolades.

[mcMike]

Originally Posted by CurtC

Google Earth uses bearings relative to true North. The difference at Washington, DC, between true and magnetic North is close to 10.75 degrees, so that a flight path of 70 degrees relative to magnetic North would be 59.25 degrees relative to true.

What "eyewitness-path" are you referring to? The eyewitnesses saw the plane hit the light poles, right? You're not talking about the Citgo employee that the Loosers talked to five years later, are you?

59.25 matches perfectly in my photoshop-pixel-accuracy. (I measured 61) . The eyewitness-path was from from 911-strike.com the image name flight_path.jpg (can't post links yet). It was reported to be based on multiple eyewitness accounts.

Anyway, Thank You all. The heading is solved nicely.

btw, What is the statement JDX is actually making from the CVS ?

[Anti-sophist]

Originally Posted by UnderTow

The FDAU syncs all this data within tolernance per type and relative time to either it's inernal or external clock which also is the Time Parameter(data) (all data is now sync'd to 'measured time' within spec tolerance) and assembles the frame.
The FDAU sends this assembly of data using the 717 frame to storage(FDR).

Once the frame is time stamped, the amount of time taken to record it is of less concern since the time of occurrence for the data in the frame is clearly indicated by the frame time stamp.

A Frame is a time-tagged grouping of recorded parameters. Since the Frame Time Tag applies to all parameters in the frame, the amount of time that elapses while acquiring the parameters should be minimized.

Utterly and hilariously false. Feel free to compare the above gibberish with the footnote in the ARINC graphic you posted:

Quote:

The age of the NZ sample depends on how old it was when it arrived in the pool and how long it sat in the pool before time T-1. The source latency and transmit delay determine the age on arrival. The update rate determines the time spent in the pool before being used.
It appears that the Nz is 2/64 second older than Radalt because of its implied timetag, but it could actually be much newer.

Explain to me how, if the DFDAU corrects all the errors, the Nz sample can "appear" 2/64 older in the ARINC frame? How can it actually be "much newer"? I though these errors are automagically corrected in the DFDAU!

Your entire arugment is that all the parameters share a single timestamp. This is completely and utterly false. It's laughably false.

[Anti-sophist]

Originally Posted by mcMike

btw, What is the statement JDX is actually making from the CVS ?

He is infatuated, mostly, with the altimeter and proving that the plane couldn't have hit the lightpoles, given the speed and height shown in the CVS file.

[mcMike]

Originally Posted by Anti-sophist

He is infatuated, mostly, with the altimeter and proving that the plane couldn't have hit the lightpoles, given the speed and height shown in the CVS file.

Ok. Thanks. That was the thing I supposed.

btw, I think I found some information for the inaccuracy in flightpath reconstruction. Can't post direct links but google: "NTSB flight path reconstruction" Should be the first link to NTSB-site "3D Animation of Recorded Flight Data".

Now, the question; Did Flight77 FDR have GPS for absolute-referencing or Intertia for Dead Reckoning? AND did NTSB use that data in the animation?

[CurtC]

Originally Posted by mcMike

Can't post direct links but google: "NTSB flight path reconstruction" Should be the first link to NTSB-site "3D Animation of Recorded Flight Data".

Here's your link: http://www.ntsb.gov/Events/symp_rec/...ors/bolduc.htm

By the way, if you remove the "http://" from the front of links, I think the board will allow you to post that. Readers will have to copy and paste instead of simply clicking, but it's easier than a description of how to Google it.

[UnderTow]

Quote:

Utterly and hilariously false. Feel free to compare the above gibberish with the footnote in the ARINC graphic you posted:

Quote:

The age of the NZ sample depends on how old it was when it arrived in the pool and how long it sat in the pool before time T-1. The source latency and transmit delay determine the age on arrival. The update rate determines the time spent in the pool before being used.
It appears that the Nz is 2/64 second older than Radalt because of its implied timetag, but it could actually be much newer.

Explain to me how, if the DFDAU corrects all the errors, the Nz sample can "appear" 2/64 older in the ARINC frame? How can it actually be "much newer"? I though these errors are automagically corrected in the DFDAU!

Your entire arugment is that all the parameters share a single timestamp. This is completely and utterly false. It's laughably false.

Funny in that both statements are from ARINC. But whatever, your design is better than anything I've seen.

And yes, Anti-S would have you believe that the Altitude and Airspeed could be off by as much as 3 (or even 4) seconds relative to each other. At that when is says 09:37:44 in the CSV file it really means nothing becuase "Any attempt to correlate FDR times to non-FDR (“real world”) times is flawed from the get-go" and the NTSB doesn't know what they are doing so we'll just have to throw away the CSV until I can show him the actual frame definitions. (Hint: note the location of of these parameters in the graphic you keep referring to)

Let me know when your done with your paper. I've got a guy at Boeing who might give you a critque you'll accept.

[beachnut]

Originally Posted by UnderTow

Funny in that both statements are from ARINC. But whatever, your design is better than anything I've seen.

And yes, Anti-S would have you believe that the Altitude and Airspeed could be off by as much as 3 (or even 4) seconds relative to each other. At that when is says 09:37:44 in the CSV file it really means nothing becuase "Any attempt to correlate FDR times to non-FDR (“real world”) times is flawed from the get-go" and the NTSB doesn't know what they are doing so we'll just have to throw away the CSV until I can show him the actual frame definitions. (Hint: note the location of of these parameters in the graphic you keep referring to)

Let me know when your done with your paper. I've got a guy at Boeing who might give you a critque you'll accept.

does this mean you are john in hiding

not to tell any good stuff on FDR on AA77, like explain it,

something other than an arguement of FDR design, more on what the heck you think about the data missing, and how that missing data accounts for getting the aircraft on the ground

I would like to ask; do you think the FDR was found in the Pentagon?

yes flight 77 FDR?

and do you believe the terrorist did that real bad turn?

and or flew the planes at all on 9/11?

tell more than just your war against AS

[Anti-sophist]

Originally Posted by UnderTow

the NTSB doesn't know what they are doing so we'll just have to throw away the CSV until I can show him the actual frame definitions.

----

Seriously, how many times are you going to repeat this idiotic tripe? How many times? Seriously? THE NTSB IS NOT INCOMPETANT. THE NTSB, THE FAA, BOEING, THE ARINC STANDARD, AND THE ENTIRE DATA ACQUITION INDUSTRY KNOWS ABOUT THESE ERRORS AND CORRECTS (OR ACCEPTS) THEM EVERY SINGLE DAY. You _aren't_ correcting them. You deny they even exist. You are an amatuer trying to pass yourself off as a professional. THE NTSB ISNT THE ONE NEGLECTING THESE ERRORS, YOU ARE.

-----

I have formed a nice easy copy-and-paste block so I can just repeat the above section after every single post of yours. You seem to love to repeat this ridiculous nonsense, over and over and over and over.

The ARINC standard isn't contradictory. The problem is in your head, not in the standard. The ARINC standard makes perfect sense to someone with sufficient background to understand it. You claim to understand it, but you have utterly no idea what an "implied timestamp" is. That's like data-frame 101. You think all elements of a frame have the same time stamp. You think the entire frame was measured at the same instant. That is UTTER gibberish.

Since you can't answer these simple issues, do what you do best: ASK QUESTIONS

Ask your friend at Boeing about it. Ask him if all samples in a single frame happened "at the same time". Ask him what an implied time stamp is. Ask him how things can appear to be "older" but actually be "much newer".

Ask the questions that you CTers are so good at asking.

Why are you so afraid to deal with this very simple issue? Why are you so scared of this footnote? Where is your explaination? You dismiss mine saying it's wrong, so I ask you, given my misunderstandings, explain how the footnote says what it says.

You can't. Why?

[beachnut]

there is a possible dolt posting the NTSB video of the FDR on youtube with his own smart remarks;

http://www.youtube.com/watch?v=i-Q8nSEeUec&eurl=

http://www.youtube.com/watch?v=DzR-q0ijbV0


this possible dolt, I think, claims to be a pilot.

This could be true, not all pilots are immune from being dolts in the CT movement, there are about 5. John could be 5 + 1!

He puts in comments which are real dumb for a pilot, holding an ATP (airline transport pilot, if you find his name you can see if he is current as an instructor cause the FAA works for you at FAA.gov, you need his real name, if he has one).

example: he says, why did the terrorist not just dump the nose and go for the pentagon from 7,000 feet! (20 to 30 degree dive, could it be he never did that before? But I bet he did a 360 degree turn to loose altitude, johndoe can not tell you that cause his stupid remark would not be smart any more)

This is a dumb statement for a pilot to make, unless he is a terrorist thinking this is a good idea! Yet our terrorist were pilots, they actually passed the same system that gave us JohnDoe, and therefore scares me John could dumb the nose and try to land from a 20 to 30 degree nose low approach, which is 17 to 27 degrees more than normal approaches to landing, and much more than ever used for normal airline flying.

Then the expert, johndoe, leaves us at hundreds of feet in the air near the Pentagon. No real explanation, nor does he seem to what to tell you why.

Does JohnDoe know by accepting the video as the FDR data, he is proving flight 77 did hit the pentagon and the FDR was recovered from inside the pentagon where flight 77 hit.

JohnDoe has finally figured out the video and the ground do not match up? Does he explain? No, JohnDoe, and the nut case JaneDoe, take this as proof something is up!

JohnDoe and JaneDoe are unable to use their brains except to produce BS on 9/11. John goes on show light poles, not part of the NTSB video, as proof flight 77 missed. Will he ever tell us what did hit the poles?

Jane could help, it was beamed down by Scotty on que!

Anyway, could someone help John, or ask John how, as has been asked, the data was lined up with the ground?

Some reasons the ground may not line up. No accurate GPS/INS data survived the crash of 77. Using radar data which would be off by blocks. Using Microsoft roads and junk and Bill gates does not care if my brothers house is not in the lake!

Let me count the ways!

It would be cool if John would present all the details before getting Jane excited they have caught the government in a cover up!

We are unlucky/lucky these two were not after Nixon, he would still be president!

Poor John is still airborne near the Pentagon, he needs some help. Doctor!

[Darth Rotor]

Originally Posted by mcMike

Now, the question; Did Flight77 FDR have GPS for absolute-referencing or Intertia for Dead Reckoning? AND did NTSB use that data in the animation?

Irrelevant.

The pilot (based on FDR info) deselected the auto pilot and was flying by hand in the terminal phase of the flight.

CR

[Anti-sophist]

Since it is _painfully_ obvious you are unable to answer the question about the footnote, I've decided to stop rubbing your nose in it, and I will walk you through the answer, if you are willing. Once you understand what I am saying, you can fire off an email to your Boeing friend, and see if my answer matches his...

Let's start at the very beginning, UnderTow, let's say each frame represents 1 second, and each frame is made up for 10 words. Just for the sake of easy math. Let's assume we are at time=0, and we are ready to start a new frame. I'll even skip the harder question.... (about when it was measured)... What time interval does word 5 get sent to the recorder from the DAU? (or, rather, what time does the first bit get sent, and what time does the last bit get sent)

If you don't get 0.4s to 0.5s for this, we already have our first problem. Your previous post seems to claim that "all" the words get recorded at the same time. I am going to assume I misread it, and give you a chance to agree with this, before moving on.

[beachnut]

Originally Posted by mcMike

Now, the question; Did Flight77 FDR have GPS for absolute-referencing or Intertia for Dead Reckoning? AND did NTSB use that data in the animation?

http://www.ntsb.gov/info/foia_fri.htm

I do not think the FDR recorded position

http://www.ntsb.gov/info/AAL77_fdr.pdf

quick review i did not find GPS or INS information

there is plenty of information every second for Dead Reckoning, all you need is time and heading, you have it, and that give the NTSB all it needs, but you are correct in thinking we need more to place the plane at the real position it was at!

DR will not give exact, but it will give what we have, all the data, knowing the speed, and heading, attitude, etc, ;you can produce the Video.

I think lining up the ground is another story! I think they used radar data and where it crashed to line up the track

but I think the track pure FDR data only, relative position calculated just from FDR data, it may not line up exactly with the ground as seen on the Video,

in fact some information is missing, so you could line it up better if you had the time and money

kind of a waste knowing the FDR was found in the Pentagon where flt 77 came to rest

but the CT world will make this mismatch proof of a CT, like Johndoe and Janedoe, wonder if they are going to start dating?

[apathoid]

Jeez, okay, now I'm confused.

Is UT talking about the ARINC(429) data getting sampled by the DFDAU from multiple busses, or the serial ARINC(717) stream from the DAU to the DFDR? I've reread his posts and he's all over the place talking about both ARINC specs. The data doesnt get sampled as A717/573/747 as I alluded to above, it gets sampled as 429. So all this data must be dewrapped, rewrapped and time tagged in the serial output. Wouldn't the ARINC 717 time tags take place after the event is sampled(by the event marker?). I'm not too clear on when this time tag actually happens. It cant happen as the data is getting sampled, so it must happen after its reformatted/conditioned as 717 ...or does it happen in the FDR?

I've actually read the 2100 FDR manual as well as the 2233000 DFAU manual and nowhere does it mention this time tag.

[apathoid]

Originally Posted by mcMike

Now, the question; Did Flight77 FDR have GPS for absolute-referencing or Intertia for Dead Reckoning? AND did NTSB use that data in the animation?

The 757/767 use Inertial Reference Position for position updating. GPS is only used for terrain floor mapping in the Enhanced Ground Proximity Warning Systems and Airshow(the moving map display in passenger entertainment system).

IRS isnt as accurate as GPS, not even close. It can display both Magnetic Heading as well as True(there is a mag/true switch).

Also, the IRS postion was sampled, recorded and plotted and is available in the CSV file.