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AA77 FDR Data, Explained

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THIS ENTIRE SECTION IS SO FULL OF MISTAKES IT BOGGLES MY MIND. INSTEAD OF COMMENTING EVERY MISTAKE IN HERE I WILL JUST UNDERLINE THEM.
Good. Saves laymen like me, who know nothing about these things, the bother of understanding pesky explanations about why they're wrong. You could have saved yourself a lot of writing, though, by highlighting A-S's post and clicking on the underline button.

YOU SHOULD DELETE THIS ENTIRE FOLLOWING SECTION
I'm sure A-S will go right ahead and do that. If you told me to change something I'd written, without explaining why, I'd do it immediately.

In the meantime, at some point will you be explaining why A-S's analysis is "tripe?"
 
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It was about getting you to come back to finish what you started but chose not to continue. Looks like I was successful.

Your actions do not influence me in the least. Just because you lost patience does not mean I have chosen not to continue.
Much like these people who continue to hang on my use of the word 'cargo', it is irrelevant in this thread.
 
Your actions do not influence me in the least. Just because you lost patience does not me I have chosen not to continue.
Much like these people who continue to hang on my use of the word 'cargo', it is irrelevant in this thread.

you can not even explain your term cargo, except as a rude term for pax, and you now explain tech data on the FDR, or some CT idea that a cargo plane did the dirty deed on 9/11

get to the lay person meaning

is flight 77 still airborne?
 
False. Action: I type a post directed to you. Reaction: you reply and say my actions do not influence you.
Wait, a moment Gravy, he is one of JDX's pals, perhaps we should rephrase this in terms he may better understand...

PwNed!!!!11!! LOlZOoRZ!!1!11!eleven!!!
 
Wow, what an amazing bunch of nutters. I'm sure it makes the Circle-J that much more entertaining when you stand in the middle and get touched from all sides.
Whatever keeps your ego afloat Gravy.
There's probably a medical term for that type of thinking.
 
Wow, what an amazing bunch of nutters. I'm sure it makes the Circle-J that much more entertaining when you stand in the middle and get touched from all sides.
Whatever keeps your ego afloat Gravy.
There's probably a medical term for that type of thinking.


so does this mean you can expain flight 77 FDR?

get to a point about FDR on 77?

what is your point?

questions?
 
I have stripped away the following items, from your response, UnderTow

1) Self-congratulations
2) Personal Insults
3) Unsubstantied claims (you telling me I'm wrong without any justification)


I am left with the following cogent issues:

On the "About me" section...
Why bother putting this in here. Based on your other comments in this thread, the body of your text should stand on it's own. Perhaps to add weight and an air of authority? Since you don't actually reference any industry standards and prior work, this must be your personal opinion.
I find it somewhat strange that you had the most to say about the "About me" section. The reason I included it is because it's customary to accompany biographies with documents in scientific literature. I know that the traditions of scientific publication aren't highly held in the CT world, but it's a habit I've gotten into. Pick up any scientific journal, flip to the end of any article, and you'll see a short bio of the author.

he "problem" you attempt to create is something that these companies and people have been working with for several decades. No one "sees" a stream of bits and attempts to "make sense of it".
Yes, I am describing the motivation for the standards, and explaining how the standards solve the technical challenges. I'm using a simple narrative to describe the technical challenges of dealing with this type of data. If you honestly thought I meant an actual engineer sits down with 1s and 0s and starts from scratch every time, you've utterly and severely missed the point. The purpose of this was to EXPLAIN why the standards are the way they are, and what issues they solve.

You continue the mistake of earlier by linking a "word" which a value for Alititude and that you can add the Time Slot to the Time Stamp for the Real World Time of the Data Event as it happened.
The Time Stamp recorded in the Data Frame is exactly what it is. A Time Stamp for ALL records recorded in that Frame.
These statements are provably false. Even the footnote of the jpg's YOU posted prove that these statements are false. The implied time stamp (what you call the "time slot") does not equal the time it actually happened. That is the entire point of this document -- which you clearly are not understanding.

Here is the footnote of those jpgs: (bolding mine, as it DIRECTLY contradicts your previous statement)
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.
Your own graphic has a footnote that literally proves that the nonsense you just tried to pass off is false. The implied time tags are NOT the measured time tags. End of story. The raw FDR data will include these measured time tags seperately if that level of precision is necessary. You do not have the raw FDR data, so you only know the implied time tags, not the measured ones. (and you don't even know the IMPLIED ones because you don't have the frame descriptor.. you know a RANGE of time that the implied time tag falls in)

That is nonsense and for the people that actually work on this for a living it's an offense to thier efforts and achievments.
You mean like me? I got paid for building these exact systems...
 
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UT, you're in the running for the monthly JREF Forums Lowest Signal-to-Noise Ratio Award. If you are capable of doing so, please proceed with your analysis of the data.

My real purpose here is to reply to a post by AntiSophist (cc: Apathoid)

Oh joy oh joy the fun we're going to have...
 
Did I just influence you beachnut? ooo, I feel the power of the Gravy influence now...

do you have any real info on the FDR and explain anything?

for instance, what would the altimeter error be to correct the altimerter reading at 463 KIAS, or is the FDR reading corrected for speeds in excess of placard?

Since the altitude is realy PA, what was the real setting for the pentagon, like 2992 is a standard, what was the reading at the pentagon, to correct the PA for local pressure?
 
do you have any real info on the FDR and explain anything?

for instance, what would the altimeter error be to correct the altimerter reading at 463 KIAS, or is the FDR reading corrected for speeds in excess of placard?

Since the altitude is realy PA, what was the real setting for the pentagon, like 2992 is a standard, what was the reading at the pentagon, to correct the PA for local pressure?

DCA was experiencing 30.23, so the pressure altitude wouldve been -280 ft at ground level.. and Pressure altitude is always referenced to 2992 and doesnt need correction.

Myself, I think the error in PA has 3 sources:

1) The Air Data Computers not calibrated for high speed/low altitude flight. RMackey made some good posts on this.
2) Pneumatic lag out of the range compensated for by the ADCs. Lag increases with an increase in vertical speed.
3) The last second or two missing from the FDR plots. A-S has given us great insight as to why it may be "missing"..
 
1) The Air Data Computers not calibrated for high speed/low altitude flight. RMackey made some good posts on this.
2) Pneumatic lag out of the range compensated for by the ADCs. Lag increases with an increase in vertical speed.
3) The last second or two missing from the FDR plots. A-S has given us great insight as to why it may be "missing"..

Also time lag associated to measurement/calculation by the ADC to when it was recorded.
 
I just wanted to say this thread gives me a headache. Good effort all of you techie minded people who have any idea what is being discussed... :p

-Gumboot
 
DCA was experiencing 30.23, so the pressure altitude wouldve been -280 ft at ground level.. and Pressure altitude is always referenced to 2992 and doesnt need correction.

Myself, I think the error in PA has 3 sources:

1) The Air Data Computers not calibrated for high speed/low altitude flight. RMackey made some good posts on this.
2) Pneumatic lag out of the range compensated for by the ADCs. Lag increases with an increase in vertical speed.
3) The last second or two missing from the FDR plots. A-S has given us great insight as to why it may be "missing"..

right on 2992, but when you get back to MSL or above the ground you need the local altimeter setting, set the local in your altimeter and you usually have very close to the MSL at the airport when you arrive

yep, I got AS stuff, and it sounds good to me and I have a MSEE too, but no recent practical stuff

I was still wondering if the speed caused anymore errors, the plane is in an overspeed condition at 463 KIAS, for being that low it is going too fast
 
Wow, what an amazing bunch of nutters. I'm sure it makes the Circle-J that much more entertaining when you stand in the middle and get touched from all sides.
Whatever keeps your ego afloat Gravy.
There's probably a medical term for that type of thinking.

does this mean you can not exlpain anything about the FDR on flight 77?

or does this mean you think a missile hit the Pentagon?
 
It's nice to see JDX actually posting where people will be critical of his statements, rather than accepting them as gospel truth.
Bit of a reality check might shock him back into the woodwork where he can do less harm.
 

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