AA77 FDR Data, Explained

[Jonnyclueless]

I thought he already said goodbye. How can we miss him if he won't go away? (Song cue!)

"Have fun stormin da castle!" - Princess Bride

 

[Reheat]

I'm sorry, Beachnut's post was so bad I had to repsond again.

Oh, we knew you'd be back. It's not a surprise.

Prove this applies to 757-200 jets.

Why? The onus is on you buddy. Can you prove that it didn't happen?

Oh no, different airlines and different FDR!!! What shall I do?!

No, it's not really the airlines it's a difference in equipment. Apparently, everything you've ever owned in your entire life worked according to the manufacturer. Is that right? Mine and beachnuts experience is different, we've seen electronic gear not perform up to specification and break.

Please tell me what your point is, and what bearing this may have?

Different manufacturer and I just told you the rest.

This is exactly like saying a DELL computer and an IBM computer can't run the same software!

No it isn't. You're comparing apples and oranges.

The name of the airline doesn't matter, and neither does the MFG of the FDR!!

Please list your FDR qualifications again, I must have missed it the first time.

They confrom to a SPEC and are certified the same way. Either FDR must meet the 500 millisecond store time!

So? Have you proven that an FDR in a 1991 aircraft must meet this spec? Pssst... No you haven't.

You call yourself a competent individual, yet you show now knowledge of the system!

Where is that statement from beachnut that he called himself competent? At any rate he could be a mental midget and defeat your hearsay, incredulity, and deficient knowledge of the subject you are attempting to rant about.

Once again, you have no clue of how this all works. You forgot to tell everyone one important thing about Swiss Air and why it lost 360 seconds of data.

Most everyone here has better reading comprehension than you. The Swiss Air incident was previously posted and the reason for it's crash.

Why don't you tell everyone WHEN and HOW the FDR lost power. Is it anything close to what happened to UA93, or AA77?

I don't know about AA77, do you? Tell us what happened to UA93 that you find unusual related to the FDR. On second thought I really don't want to hear your opinion.

We're all waiting...please humour me.

No, you're waiting. You don't need to be humored. You are very humorous without anyone saying anything.

Show your math and correction for the math. Use forumlas, images, or diagrams if you need to.

You were provided a link way back early in the thread to the math, formulas, and diagrams. Reading comprehension problem, eh?

I pray that anyone reading this thread understands how incorrect Beachnut's claims are.

I'll bet everyone understands what a dunce you are based on your posts in this thread.

For the record, nobody has come forth with the following:

- Explanation of odd entry damage to support right engine and tail section of AA77 passing through.

Addressed several times, you just don't like the answers.

- FDR RADAR Altimeter missing from CSV File

Same as above

- Up to two seconds missing for CSV file

We don't know why, do you? Your expert professionals at pffft should be able to explain it, why are you asking non-experts here?

- Pressure altimeter not correctly set on descent in NTSB video

Don't you know that according to some troofers, Arabs live in caves and can't fly airplanes.

- Why NTSB Animation stops short of impact to Pentagon wall

This is JREF. That are you asking an NTSB question here?

- How an FDR functions and stores data

I thought you knew. According to several posts you seem to indicate that you know everything about and FDR. Do you think this is an avionics school or something?

- Proof that an FDR takes longer than 500 milliseconds to store data while powered

Why?

- Explanation of E4-B video (CNN)

What about it? What does it have to do with anything discussed? Do you think everyone here knows everything about a National Asset whose schedule is not available to the general public. Why do you want to know about US Secrets anyway? Do you have a "need to know"

- Norman Mineta's testimony (C-SPAN video)

Addressed more than once.

I thought you were leaving? Apparently, you haven't had enough thrashing, but I'm getting bored with your antics, so I may turn this over to those who haven't had a chance to beat up on you yet.

 

[Mr.Herbert]

I was just watching a show on Animal Planet. This 9ft Seal was eating Penguins. Octopus were eating baby turtles... I had to turn it off... too gory. Then I come to this thread...Should I feel the same way about Turbo Fan as I do for the baby Turtles and Penguins?

 

[funk de fino]

[
I know more about FDR than you have shown to date in this thread.
If you're too slow to understand the parallel between both computer
systems, then god help you.

No you have not

Do you understand how the error codes are set in an FDR? Yes, or no?

Yes

Please explain.

Eh

Why would the plane show impact of the poles? Apparently there are pressure sensors on the airplane, and bleed air ducts on the wings, and RPM monitors
for jets.

Completely and utterly wrong. If the pole hits the slats at the front there would be no sensor that would pick it up. If it damages the engine then maybe just the engine sensors would poick up a disturbance. But none of the vib or pressure sensors would have measured it if it hit the wing. Get some edcation before you come here and act so arrogant and try to show you know about aircraft.

Why would there be RPM monitors on the wing?

Why would any bleed air on the wing pick up anything like a pole collision?

When the plane strikes an object at 500 MPH, the impact against the wing creates sound, vibration, and pressure change (shockwave). None of the sensors managed to pick up any such variation.

Don't you think that's a little odd?

See above. None of those sensors would have picked it up. Stop embarrassing yourself.

 

[funk de fino]

The FDR in Flight 93, which was a 757-200, was an Allied Signal SSFDR. It was not an L3 one apparently. Why would Flight 77 have an L3 one and do you have any proof if it did and if it met the standard you have quoted.

 

[CurtC]

I think that TF believes that the standard for L3's SSFDR they make today has to apply to the SSFDR on-board flight 77. This to me is far from certain. TF, do you have any cites that show the L3 comments regarding the applicable standard would apply to the SSFDR on flight 77?

I mean, maybe it does, maybe it doesn't, but he seems to be asserting that since a standard exists today, old equipment must conform to it. That's not the way things work in the world I operate in.

 

[funk de fino]

Is it really that funny? Tell me ktesibios, are you stating for the record
that an FDR does not store fault codes if a sensor fails to respond, or
other trouble occurs on the aircraft?

Are you also stating that the write time from sensor read to SS storage takes
longer than my scanner from sensor to screen (displayed)?

Hint: ED55 and TSO-124

I think you better go and read those standards pal. They do not say what you think they do.

The TSO is only for crash survivability and has had amendments made over the years.

The ED 55 is superceded at the moment I believe, and it does not say what you have claimed. You do know that some of the parameters recorded are only recorded every 4 secs or every 2 secs or every 1 sec? The time taken from sensor to SSRD is affected by the time taken in the DAU to process and then process back the info and then write to memory.

Please show us the relevant section of ED 55 that applies and says that all data must be recorded within 0.5 secs. Then show us if the Flight 77 recorder was of this type.

You can buy a copy and post the relevant sections here.

If you cannot then you are making false claims.

 

[Turbofan]

I thought I'd update all of you with the latest. The links provided show
answers to some of the questions.

I"ll be back with more. I'm not interested in the back, and forth discussions
unless certain people can back up their claims with some sort of credible
link, photo, video, etc.

Here are mine:

I'll just throw out some PDF links showing the certifications and specs of FDR's as I continue looking around.

http://www.thic.org/pdf/Oct97/smithsind.sgresley.pdf
http://www.l-3ar.com/PDF_Files/MKT051_FA2100FDR.pdf

Here is a source that states the 500 millisecond requirement.
http://admmatapp.forces.gc.ca/TAA/ADSM/TOC...3_-_CVR_FDR.pdf
http://www51.honeywell.com/aero/common/doc...der_(SSFDR).pdf

Page 2, point 11:

"Recording shall commence in the crash protected memory within 250 milliseconds for audio, and 500 milliseconds
for flight data after power is applied and the start criteria are satisfied."

Flight Data Recorder Requirements
http://www.casa.gov.au/download/CAAPs/Airworth/42L_4.pdf

Pages 3 and 4, section 3.2 and 3.3 state:

"CAO 103.19 defines recording equipment standards, mandatory parameters required to be recorded,
their accuracy, resolution and sampling rate."

"3.3 Continuity of Recording – the loss of information shall not exceed 200 milliseconds per event and the cumulative loss shall not exceed 500 milliseconds per hour. It is accepted that power interruption may affect the simple retrieval of whole subframes of data due to loss of synchronisation. (as defined in ED112 paragraph II-3.2.1)"

Something of Interest:
http://findarticles.com/p/articles/mi_m0UB...ag=artBody;col1

From Boeing:

"We disagree with 16 samples per second [sps] as the necessary minimum recording rate for flight control parameters. We examined actual data traces from several past accidents and incidents where control motions were an issue. From this review, it became clear that the control motions are typically 'coupled' with the natural frequency of the airframe. The airframe natural frequency, and the frequency needing to be captured, was 0.5 Hz or less in all axes. Thus, we concluded that 4 sps is adequate to unambiguously characterize the flight control movements of all transport category aircraft certified under FAR Part 25."

Radio Altimeter , stored every one second. Accuracy +/- 2 feet, or 3% (which ever is greater).

Have a nice day.

 

[~enigma~]

I thought I'd update all of you with the latest. The links provided show
answers to some of the questions.

I"ll be back with more. I'm not interested in the back, and forth discussions
unless certain people can back up their claims with some sort of credible
link, photo, video, etc.

Are you really that dense 22205? Don't you get the impression that nobody is interested in CIT or Guides Who Lie's trumped up and made up baloney? Why don't you try your "post pictures and email" crap here? Are you so cowardly that you gotta do hit and run posts? Your actions disgust me.

 

[Turbofan]

That information is in response to Reheat, Beachnut and Funk De Fino.

If you don't like the discussion, then leave the thread.

Don't get upset because I'm systematically, and credibly proving that
FDR's take a maximum of 500 milliseconds to store data in order to meet
passenger jet certification.

Oh ya, and for whomever said the term beacon is not used within the
industry might want to check out this video at the 22:25 time point:

http://video.google.com/videoplay?docid=2833924626286859522

Thanks

 

[~enigma~]

That information is in response to Reheat, Beachnut and Funk De Fino.

If you don't like the discussion, then leave the thread.

Don't get upset because I'm systematically, and credibly proving that
FDR's take a maximum of 500 milliseconds to store data in order to meet
passenger jet certification.

Oh ya, and for whomever said the term beacon is not used within the
industry might want to check out this video at the 22:25 time point:

http://video.google.com/videoplay?docid=2833924626286859522

Thanks

What discussion 22205? you said you were going to act the coward and "hit and run" post. That action disgusts me. Got a problem with that, either report me (can't figure out what for) or stop your pitiful whining.

 

[Turbofan]

I didn't say anything about "hit and run posting" did I?

I said I'm not interested in the discussion at this point because certain
people just post theory without backing it up.

Reheat, Beachnut and Funk de Fino have made claims about FDR's,
power loss, incorrect math at P4T, but they have yet to show the
errors, or post corrections.

That's all I'm asking. Back it up with a link, math, etc.

Is that so bad?

 

[Anti-sophist]

I've read through all of this and to a large extent it's the same tired and misapplied attempts at "proof by regulation". Regulation and design don't trump the evidence.

I'll answer your first two posts because they contained the vast majority of your argument:

Are you stating that the data recorded in solid state memory was partially
corrupt (specifically the last two seconds?)?

Nowhere have I said anything of the sort. I simply said that not only was it possible, it was likely.

L3 communications certifies their FDR's up to 3400 g's of impact force.
Are you stating that the data recorder selectively re-wrote the last
two seconds of data upon impact ?

Nowhere have I said that.

What software are you referring to? If a bit was dropped, how is said
software effected? When you say software, are you referring to firmware
instead?

The decoding software. And not unless the firmware is involved in offloading the memory.

Would you agree that the data bus and FDR had power at least until the
nose of the plane impacted the Pentagon wall?

Presumably. But it's not a trivial assumption.

Would you agree that serial, multi-plexed data would continue to write
to the FDR solid state memory if one, or more sensors failed?

Of course.

What causes 'pressure lag', or data lag at sea level that would not be
realized at 25,000+ feet at 500+ MPH?

This is far outside my area of expertise.

Fine. Then why does the NTSB animation stop before impact? Where
is the data between the stop point, and impact point?

This is rife with unfounded assumptions. Let's start with the obvious: who says the NTSB animation was precise enough for you to determine it did stop before impact?

After 500 milliseconds (worst case), that information would not have
reached the memory and stored. Confirmed by L3 communications.

Even if this "proof by regulation" is true, it doesn't mean it made it into your CSV or raw file that you've analyzed. You've simply skipped too many steps.

Because some of you claim the impact force damaged the crash protected
memory. This is a false claim.

The only false claim here is the one you just made. No one has claimed that.

Once again, only 500 milliseconds would be corrupt. How do you explain
the missing radar altimeter info in the CSV file? It's in the raw data!

Oh this tired argument. Please for the love of God stop assuming that the CSV file was released to the public so conspiracy theorist/amatuer data analysis teams could do forensic analysis.

The CSV file is a modified version of the data so they could print GRAPHS for a single report. That's it. There are tons of parameters missing from the CSV file. They didn't see fit to put the RADALT or dozens of other of parameters into that report ... probably to keep it under 50 pages.

Once again, the animation stops pre-impact. Where is the data up until
the impact point. The FDR still had power!

You've not demonstrated that the animation's accuracy to any sufficient level. And the claim that the FDR had power, in my opinion, is only likely, not certain.

The NTSB supplied the data. It doesn't support the official story. WHy
are you slamming PFT?

Because they, and you, are lying? There's not a single shred of data that doesn't support the official story.

If your $1500.00 car computer can do all of this, you can rest assured a much more elaborate and expensive jet data acquisition system will outperform this many times over.

Please stop with this stupidity. Not only are you wrong, but you are grasping at straws. I could build a data acquisition system with off the shelf parts for a few thousand dollars that would stomp the leaving bejesus out of anything on any aircraft in the world. THATS BECAUSE MINE WOULDN'T NEED TO UNDERGO THE STRESSES AND CONDITIONS OF FLIGHT NOR... SURVIVE IMPACTS.

Please, please, please, please stop with this utterly inane and awful comparisons where you mentally rank the "technologicalness" of different machines built for COMPLETELY different purposes and pretend one must have all the features of the others because it's obviously more "advanced". It's just stupid.

 

[CurtC]

Page 2, point 11:

"Recording shall commence in the crash protected memory within 250 milliseconds for audio, and 500 milliseconds
for flight data after power is applied and the start criteria are satisfied."

That doesn't say that samples must be recorded within 500 ms of when the sample was taken, though you seem to think it does.

Further, you have not showed us where the model of FDR on the flight 77 plane was required to meet that standard anyway.

 

[Turbofan]

I think that TF believes that the standard for L3's SSFDR they make today has to apply to the SSFDR on-board flight 77.

No, that's not what I believe. I believe (and is also fact), that FDR's on,
or before Sept 11 conformed to a certification and standard which states
that information received from the sensor must be stored within 500 milliseconds.

This to me is far from certain. TF, do you have any cites that show the L3 comments regarding the applicable standard would apply to the SSFDR on flight 77?

I have posted some infomation already, and I'm working toward getting
the L3 confirmation that AA77 complied to said specifications.

 

[Turbofan]

That doesn't say that samples must be recorded within 500 ms of when the sample was taken, though you seem to think it does.

Well, I guess you haven't read the document, or the follow up quote:

"3.3 Continuity of Recording – the loss of information shall not exceed 200 milliseconds per event and the cumulative loss shall not exceed 500 milliseconds per hour. It is accepted that power interruption may affect the simple retrieval of whole subframes of data due to loss of synchronisation. (as defined in ED112 paragraph II-3.2.1)"

So , yes it does mean that specifically. It's a SPECIFICATION.

Further, you have not showed us where the model of FDR on the flight 77 plane was required to meet that standard anyway.

Well, for your information, in order to certify a passenger jet, the
FDR must meet that criteria. Don't worry, I'll provide that info as well.

In the mean time, maybe you can call up some sources and ask them
what it takes to get an airplane certified for flight.

 

[~enigma~]

I didn't say anything about "hit and run posting" did I?

I said I'm not interested in the discussion at this point because certain
people just post theory without backing it up.

Reheat, Beachnut and Funk de Fino have made claims about FDR's,
power loss, incorrect math at P4T, but they have yet to show the
errors, or post corrections.

That's all I'm asking. Back it up with a link, math, etc.

Is that so bad?

Yes...what do you think posting and running around with your eyes closed to replies is? I'm sorry to inform you that you are not nor never will be forum god.

 

[Turbofan]

Perfect, just the man I wanted to communicate with!

I've read through all of this and to a large extent it's the same tired and misapplied attempts at "proof by regulation". Regulation and design don't trump the evidence.

With respect to the data storage delay, my friend, this information TOTALLY
proves it!

This is rife with unfounded assumptions. Let's start with the obvious: who says the NTSB animation was precise enough for you to determine it did stop before impact?

- Data is missing in the CSV file
- The Animation stops before impact to the Pentagon wall

That's a pretty significant observation don't you think?

Even if this "proof by regulation" is true, it doesn't mean it made it into your CSV or raw file that you've analyzed. You've simply skipped too many steps.

Nothing has been skipped. There is no reason for data to be missing
because there is no reason for the power to be lost to the data recorder
before IMPACT.

The CSV file is a modified version of the data so they could print GRAPHS for a single report. That's it. There are tons of parameters missing from the CSV file. They didn't see fit to put the RADALT or dozens of other of parameters into that report ...

RADALT is very important because it proves the aircraft was too high
to hit light poles and the Pentagon. Now that is has been extracted
and studied, it sort of takes a bite out of the official story doesn't it?

Because they, and you, are lying? There's not a single shred of data that doesn't support the official story.

You should read back and see the list of video and photo proof that
indicates the official story is a lie. Most important the decode of the
FDR files.

Please, please, please, please stop with this utterly inane and awful comparisons where you mentally rank the "technologicalness" of different machines built for COMPLETELY different purposes and pretend one must have all the features of the others because it's obviously more "advanced". It's just stupid.

now that I'm starting to post credible sources for the FDR specs, I see
you're getting a little nervous. I'm not going to stop anything.
You want to debate this with me, let's do it.

Want to go live by chance? Phone call? I'll pay for it.

Read those links before you reply. I will be asking you specific questions.
You might also learn the proper internal workings of the FDR system.

Thank you.

 

[~enigma~]

Anti-Sophist, just take my word on this. You do not want 22205 to have your phone number unless you want your personal information posted over on LCF, CIT's excuse for a forum and PFT playpen...

 

[CurtC]

Well, I guess you haven't read the document, or the follow up quote:

So , yes it does mean that specifically. It's a SPECIFICATION.

But the SPECIFICATION does not say that data has to be recorded within 500 ms of when the sample was taken. Maybe there is a spec for that, but what you quoted is not it.

Well, for your information, in order to certify a passenger jet, the
FDR must meet that criteria. Don't worry, I'll provide that info as well.

Is certification done for a model (in this case the 757-200), or the specific aircraft (N644AA)? The 757-200 was introduced around 1982 I think, and this plane was made in 1991. Maybe you should be finding the specs for certification in 1982 or 1991 instead of 2008.