Flight 77 FDR research

Originally posted by nick7261
The FDR data is either phony, and they screwed up by forgetting about the altimeter adjustment, OR the plane that the data came from (not necessarily Flight 77) went over the Pentagon at some point, not into it.

This really opens up a huge can of worms you know...

Problem there is many Questions - if something else flew in and Flight 77 flew over, and the Black Box "proving' the crash was put in the wrong plane. And it was said to be found in the building anyway. Planted? If so, why not faked properly instead of leaving the over-the-building path programmed right in? This just doesn't add up.

Wherever the animation (and possibly FDR study, still haven't sorted that all out) came from, whether true or not, the Pilots' interpretation seems designed to open a can of of worms, of course.

Man I hate sleeping while everyone else is posting and vice-versa.

Bump. Still nobody?
I guess this isn't as exciting as I thought.

Originally posted by Caustic Logic
Bump. Still nobody?
I guess this isn't as exciting as I thought.

LOL... this might not be sexy or exciting stuff, but this may be the most important research that anybody is doing right now.

If the pilots are right, then there is a cover-up of epic proportions going on.

That said, it's also possible that the pilots (pilot?) for 9/11 truth is a fraud.

I looked over all the FOIA docs as well, and I agree with your assessment. The NTSB video isn't mentioned. What IS mentioned is readliy available online.

Second, the CSV file isn't mentioned either. So I did some digging on this to find out where it might have come from. Turns out that the flight animation programs work both ways. I.e., they can output a data file for any simulation. For all we know, the NTSB is a video from somebody playing a flight simulator game who created a csv file and said it was from the NTSB.

Also, am I understanding you right? According to the CSV file, the "hijackers" reset the trim on the altimeter on descent going through 18,000 feet? Doesn't this directly contradict the video and the P4911T?

Originally posted by Caustic Logic
By 9:37:45 the plane was - well that's the contentious point. If the PBB video is correct, the next batch of numbers will show that the alleged Hani Hanjour knew FAA protocol and observed it, adjusting the trim back to 30.2 as he descended below 18,000 feet, something that WASN'T in the video, and that the plane was therefore not just too high to have struck the Pentagon (as in the animation) but FAR too high.
[edit on 2-3-2007 by Caustic Logic]

I went back and looked at your data. I think you're drawing an incorrect conclusion. When you adjust the barometric pressure in the kohls window of the altimeter, an upward adjustment (from 29.92 to 30.23) would LOWER the displayed altitude (in this case by approximately 310ft). One of the arguments that I read through Pilots for Truth was that the plane was higher than the animation reported because the altimeter HADN'T been reset descending through FL018. You clearly show that it WAS reset. That means the 'too high' argument is wrong.

Originally posted by jtma508

I went back and looked at your data. I think you're drawing an incorrect conclusion. When you adjust the barometric pressure in the kohls window of the altimeter, an upward adjustment (from 29.92 to 30.23) would LOWER the displayed altitude (in this case by approximately 310ft). One of the arguments that I read through Pilots for Truth was that the plane was higher than the animation reported because the altimeter HADN'T been reset descending through FL018. You clearly show that it WAS reset. That means the 'too high' argument is wrong.

Really? Coulda sworn the needle went down about 300 ft on up-bound adjustment thru FL018, and they say the problem is the animation shows the plane too low and it should be higher if adjusted. one of us is confused, and I know I didn't get enough sleep. I'll have to come back to that.

So three things:
1) The Pilots are right on the animation not matching the other FDR data
2) The animation seems to have not come from the NTSB but rather a friend of theirs
3) If th CSV is correct, the hijacker reset the trim to local pressure before crashing into/flying over the Pentagon.

As for that, that's the wierdest thing I found. I'm not even sure just hat is being "trimmed," but it may have to do with safety/handlin, and may have been a tactical decision. But that he would do it precisely at the FL018 threshold is, ummm... suspicious?

Oh, and tahnks for the comments. It's encouraging to see someone else taking note of all this.


[edit on 3-3-2007 by Caustic Logic]

Here is reports from the NTSB on the flight path and ATC communicaions from the NSA archives.

www.gwu.edu...

www.gwu.edu...

Thanks Ultima! I already have the links but it's nice to see you pop in.

okay, I just looked again at the SCV data - BTW that was I think in the packet to UnderTow at P49T, not to mr. Grouch. And also I'd like to back off a bit on accusations of forgery - so far we see an uncertain paper trail.

Okay, so we've seen the manual trim set and re-set from 30.2 to 29.92 to 30.23.
i'm not sure what effect this has on altitude, but was able to locate the alt (as well as mag heading and speed) in my crappy version of the CSV file.

the recorded alt does not change at all with trim.

time trim alt
8:27:58 30.21 17938
------------------------------ FL018
8:28:00 29.91 18015
8:28:02 30.21 18093
8:28:04 29.91 18170
8:28:06 29.94 18247
8:28:08 29.91 18324
8:28:10 29.92 18402
8:28:12 29.91 18483

time trim alt
9:24:12 29.91 18205
9:24:14 29.92 18126
9:24:16 30.23 18049
------------------------------ FL018
9:24:18 30.01 17972
9:24:20 30.23 17895
...
9:25:00 30.23 18205
9:29:00 30.23 18126
9:34:00 30.23 18049
9:36:30 30.24 17972
9:37:00 30.23 17895
9:37:15 30.23 2079
9:37:30 30.23 1432
9:37:34 30.24 1049
9:37:40 30.23 496
9:37:44 30.23 173

Now this is by AAL_77_Tab, the CSV file from the Pilots. The trim was reset at 8:28, no effect on altitude. Re-set on descent, no effect. Yet it shows what the animation shows at termination: 173 feet.

and as for alt pre-takeoff? 302 feet.

so the data here shows two trim changes, 300 at takeoff, 173 at the end. The pilots insist the data and animation match except for "the blatant cover-up" of neglecting the second re-set, turning the data's real alt of 480-ish as 180. the data, however, shows 173. The animation and this CSV file match at takeoff and "landing," despite the alleged cover-up.

Has anyone gone thru the animation by itself and verified there was no switch-back recorded at 9:24? i'm not so sure now that the animation and the CSV data really are discrepant. I'm confused now...

Anyway, the cover letter sent to the pilots mentioned two appendices (parameter listings and FDR plots) and “a CD of FDR plots that the Safety Board used in writing the aforementioned FDR report.” If this data is indeed from any of these, it does not seem to match the FDR study report, which shows termination altitude at zero.

this is the one source of the three I can verify as official. the other two I;m not sure of, but they seem to match each other.

I think that's all for today.

Nope - just sa this: response to someone showing animationscreenshots:
"That's not the software they use to replay flight recorder data. Looks like your "source" likes to play a very old version of microsoft flight sim."
perspectives.com...

[edit on 3-3-2007 by Caustic Logic]

[edit on 3-3-2007 by Caustic Logic]

As a pilot you learn that on a particularly high or low pressure day, you have to be extra careful with altitudes vs. flight levels as passing FL180, you can suddenly be through your assigned altitude or flight level as you adjust the barometer in the climb or descent.

18,000ft is the "transition altitude" on a standard day (29.92 in Hg or 1013.2 mb).

High pressure day (e.g. 30.23):

17,000 ft = 30.02
18,000 ft - 29.92 X - this altitude can't be assigned
FL190 - 29.92 - this is the first usable flight level.

Highest assignable altitude: 17,500 ft (VFR), lowest flight level FL190 (IFR).

Now, if the hijacking occurred above 18,000ft / FL190 when the pilots had set standard pressure on the altimeters, despite the training the terrorists allegedly had, I don't think getting the altimeter set correctly, and on schedule, was exactly top of their list of things to do.

With that in mind, had they not set the altimeter, then the aircraft would be reporting to be LOWER than it actually was. I'm taking the 30.23 to be the altimeter setting for 9/11. A 0.01 in Hg change in pressure is 10ft change in reported altitude shown by the altimeter, so on the day in question, the altimeter would show the aircraft as being 310ft LOWER than it actually was if left at 29.92.

300ft @ 29.92 in Hg = 610ft actual altitude (remember this is reported altitude by the altimeter vs. what it actually would be).

IF the FDR is working on standard pressure, and the altitude we are seeing in the reports is ***NOT*** corrected for pressure, then the aircraft was actually 310ft higher than what was being reported.

At sea level, the altimeter would be reading NEG ##310 ft.

The significance of this? Assuming they had not reset the altimeters on the way down, the aircraft over-flew the Pentagon and missed it by 240 ft.

the recorded alt does not change at all with trim.

This suggests the FDR is working off standard pressure (29.92 in Hg). The above notes apply in this instance.

Now this is by AAL_77_Tab, the CSV file from the Pilots. The trim was reset at 8:28, no effect on altitude. Re-set on descent, no effect. Yet it shows what the animation shows at termination: 173 feet.

Assuming the reported QNH around the Pentagon was 30.23, then this puts the aircraft as actually being 137ft above the Pentagon.

What we need to establish is how many feet above sea level is the Pentagon???? I'm going back through this thread to see if it is mentioned.

Apologies for my intermittent contributions to these discussions; I don't have the time I would like to have.

[edit on 3-3-2007 by mirageofdeceit]

Originally posted by mirageofdeceit
Now, if the hijacking occurred above 18,000ft / FL190 when the pilots had set standard pressure on the altimeters, despite the training the terrorists allegedly had, I don't think getting the altimeter set correctly, and on schedule, was exactly top of their list of things to do.

I wouldn't think so either, but the Pilots video and the data I've looked at show them doing just that, and just on time (just before passing 18000)

And thanks for the explanations, it'll help clarify to anyone reading this what these numbers mean.

With that in mind, had they not set the altimeter, then the aircraft would be reporting to be LOWER than it actually was. I'm taking the 30.23 to be the altimeter setting for 9/11. A 0.01 in Hg change in pressure is 10ft change in reported altitude shown by the altimeter, so on the day in question, the altimeter would show the aircraft as being 310ft LOWER than it actually was if left at 29.92.

Are you guys trying to confuse me? Maybe I'm misreading you. The whole point is that's what's in the animation is supposed to be off by 300 ft from the CSV data or whatever data "they recieved" becuase the trim WAS reset (as in CSV) but not in the animation. Yet they're not off. The final animation alt of 180 is not any 300 feet off from the CSV alt. of 173 at the end.

The significance of this? Assuming they had not reset the altimeters on the way down, the aircraft over-flew the Pentagon and missed it by 240 ft.

the recorded alt does not change at all with trim.

This suggests the FDR is working off standard pressure (29.92 in Hg). The above notes apply in this instance.

I dunno. I need to tak a nap and come back to this later. There are implication's I can't grasp now, and the meaning behind the numbers is eluding me, which means only tiredness creeping up. If you happen back, please re-examine the trim-alt list above and see am I reading this wrong? Is there not a re-set there?



[edit on 3-3-2007 by Caustic Logic]

You need to understand the readings the FDR take, and altimeters. Cue a few drawings........



A few points to note. When I say "altimeter" or "altimeter reading" I mean what the instrument in the cockpit is reading. Literally.

When I say "aircraft altitude" I mean the altitude the aircraft is actually at, regardless of what the altimeter reads.

Hopefully that will make the next points clear.

The pressure on the day appears to be 30.23 in Hg. "Standard Pressure" is 29.92 in Hg, and is used for flight above FL180 (for the USA). The reason is so that local pressure is not a factor to ATC when giving aircraft altitude assignments. They tell an aircraft to be at FL200, and because all aircraft are set to 29.92 on the altimeters, around any particular aircraft (which is all that matters) they will all be at their assigned flight level. The reason this is done is for separation.

RVSM = Reduced Vertical Separation Minima. This allows aircraft to have a vertical separation spacing of 1,000ft. To make life easier on everyone, the standard pressure was determined to be 29.92, so no-one has to worry about what the local pressure is as they fly. Below the flight levels, and you have to keep adjusting your altimeter to the local altimeter otherwise you could hit something, like a mountain.

The reason why 29.92 exists as the standard pressure in aviation, is because this figure is taken from a set of scientific standards known as the "International Standard Atmosphere".

An altimeter is calibrated so that at 29.92 in Hg at sea level, it reads zero ft. As you climb, the pressure changes, and so the altitude that it reports changes (goes up).

Now, if the pressure at sea level is 30.23, the pressure has risen. Because our altimeter is still set at 29.92, it will read NEG 310 ft. That is, until we set our altimeter to the local pressure of 30.23, then it will once again read zero ft.

All altitudes are measured relative to mean sea level, or MSL. Airport elevations are reported as feet above MSL. Again, if the local pressure is 30.23, then we need to set our altimeters to 30.23 also, otherwise we get an incorrect reading of our altitude.

IIRC, FDRs record altitude relative to standard pressure (29.92) at all times, but SEPARATELY record the altimeter setting as set by the pilots on their instruments (this is why whilst the set pressure changes, the altitude read out does not in the recordings). When playing back the FDR, the investigators know the pressures involved as they will have all the met from the day and the surrounding airports to tell them what it was the pilots should have been using. This is where the confusion is arising in this discussion.

It would seem that some people are oblivious to the point about the FDR, whilst others are playing on peoples ignorance of how one works. Taking this sites motto (deny ignorance ) and you find that the FDR can be made to lie without doing anything (if you don't know how it works).

Had 9/11 been a low pressure day (e.g. 29.72) then to fly at 300 ft MSL with the altimeter set to 29.92 would mean you are actually just skimming the water at 100 ft, and about to take a bath.

As 9/11 was a high pressure day, to fly at 300 ft MSL with an altimeter set to 29.92, means that you would actually be flying 610 ft above the water.

The Pentagon.....

The Pentagon is about 75 ft tall. The ground it is sat on is approximately 175 ft above sea level. 175+75 = 250 ft.

Pressure = 30.23 in Hg. If our altimeter is set to 29.92 then our altimeter actually reads NEG 135 ft at 175 ft.

So, if our 29.92 altimeter reads 175 ft, then we are actually at 485 ft, or 485-250 = 235 ft above the roof of the Pentagon.

Do you see the problem now? You can't hit it if you're above it.

[edit on 3-3-2007 by mirageofdeceit]

Originally posted by mirageofdeceit

The Pentagon is about 75 ft tall. The ground it is sat on is approximately 175 ft above sea level. 175+75 = 250 ft.

Pressure = 30.23 in Hg. If our altimeter is set to 29.92 then our altimeter actually reads NEG 135 ft at 175 ft.

So, if our 29.92 altimeter reads 175 ft, then we are actually at 485 ft, or 485-250 = 235 ft above the roof of the Pentagon.

Do you see the problem now? You can't hit it if you're above it.

[edit on 3-3-2007 by mirageofdeceit]

Ah, got it! I'm mostly refreshed now. I'm seeing the difference between real and displayed altitude, and could probably locate the numbers and see the diff, but no time now. And the altitude at the Pentagon is really that high? Huh. I was wayyyy off. That helps me some. So a 173 reading, if accurately for MSL, would have the plane just about at ground level, right?

So Q: If a 29.92 setting at 175 alt would actually mean 485 feet, which I get, where would a 30.21 reading put it if the alt reads 173? It would be at 173, right? I'm trying to get past the animation here - that's the relevant setting, 30.21 and 173 feet, what the data supposedly really shows (see above) if we ignore the incorrect animation. It seems you still aren't getting that. Or are you?

And another Q: If the animation's last frame shows an alt of 180, whatever the real altitude, why was it still pictured about 180 feet above ground level instead of above sea level and on the lawn basically? That seems another off point now that I realize the alt of the builing...

Caustic. You're exactly correct. My bad. In my head I was sure it ran opposite but then when I took my plane up yesterday I checked and sure enough.... I'm an idiot. I'll be quite now.

Originally posted by jtma508
Caustic. You're exactly correct. My bad. In my head I was sure it ran opposite but then when I took my plane up yesterday I checked and sure enough.... I'm an idiot. I'll be quite now.

So what's the verdict on the animation vs. the csv file??

I'm totally confused at this point...

1) did the trim get re-set on the descent through 18,000 ft?

2) was the altitude correct at the end of the animation or not? Was it showing too low?

3) Does any of this even matter since there is no way to authenticate to animation or the csv file at this point?

Originally posted by jtma508
Caustic. You're exactly correct. My bad. In my head I was sure it ran opposite but then when I took my plane up yesterday I checked and sure enough.... I'm an idiot. I'll be quite now.

No prob. Yhis makes me happy. You actually fly, huh? Cool. Closest I ever got was watching levar burton fly a crop duster on Reading Rainbow.

As for the overall numbers, compariosons between sources, and legitimacy of those sources, I'll have to make a big chart at this point. I think the research is near done. Yayyyyy!

Anybody posting on this thread is respectfully asked that when referring to the altimeter set or reset going UP through the Transition Altitude or coming back DOWN through the Transition level is requested to use the word "altimeters set" or "altimeters reset". There is no 'trim' on an altimeter and the term is never used in regards to an altimeter. And it is confusing to a pilot to read altimeters were 'trimmed'. Nothing gets "trimmed" unless it is the elevator or rudder or ailerons or you are getting a haircut. Thanks.

Originally posted by johnlear
Anybody posting on this thread is respectfully asked that when referring to the altimeter set or reset going UP through the Transition Altitude or coming back DOWN through the Transition level is requested to use the word "altimeters set" or "altimeters reset". There is no 'trim' on an altimeter and the term is never used in regards to an altimeter. And it is confusing to a pilot to read altimeters were 'trimmed'. Nothing gets "trimmed" unless it is the elevator or rudder or ailerons or you are getting a haircut. Thanks.

Welcome Mr. lear! I'm pleased to see you weigh in here. I've respected you since I saw you back down over the tiny hole in the Pentagon. Some folks would've kept arguing, but you responded like a human being.
thanks for the pointer. As I've noted in the thread, I have almost no knowledge of such issues, but feel compelled to wade in nonetheless. Altimeter set on the way up then, and re-set on the way down makes sense to me. I used "trim" as "trim up" and "trim dn" were the labels next to - or near, anyway - the values I cited. I didn't even know what's being trimmed...

So "trim" is Out! And other points of confuion - it is confusing. I' think I've managed it somewhat poorly, and am a little confused myself... I gotta get this together a bit better.

I have a question, if you don't mind Mr. Lear - what are the practical applications of resetting the altitude at that threshhold? Is it merely an FAA reg or something affecting handling/etc that a suicide hijacker might want to do for its own sake? And what would prompt an al Qaeda attacker to do so just at the FAA-recommended time? My friends I've asked find it odd, but feel there may be a simple explanation...

Sorry..

Originally posted by nick7261
So what's the verdict on the animation vs. the csv file??

I'm totally confused at this point...

1) did the trim get re-set on the descent through 18,000 ft?

the altitide was both set and reset according to the data in the CSV, precisely at 18,000 each way - the second time in fact a hair early.

2) was the altitude correct at the end of the animation or not? Was it showing too low?

I still need to check that... the sources oddly match (173-180) despite the alleged cover-up.

3) Does any of this even matter since there is no way to authenticate to animation or the csv file at this point?

It matters to the extent that the Pilots' video and such arguments matter, and I'm not done trying to figure out what's what and "authenticate" - ie, verify who says it's real, not that I totally believe anyone. This could theoretically ALL be fake...

Problem is too many projects at once...



[edit on 4-3-2007 by Caustic Logic]

Originally posted by Caustic Logic
I have a question, if you don't mind Mr. Lear - what are the practical applications of resetting the altitude at that threshhold? Is it merely an FAA reg or something affecting handling/etc that a suicide hijacker might want to do for its own sake? And what would prompt an al Qaeda attacker to do so just at the FAA-recommended time? My friends I've asked find it odd, but feel there may be a simple explanation...

Thanks Caustic Logic. The pilot sets the current or field barometric pressure in the altimeter so that his altimeter reads the exact same altitude as the airport and his altimter reads the same as all the other planes around him. All altitudes below the transistion altitude (18,000 feet) are assigned assuming the pilot is set to local barometric pressure. Whenver you fly into a different ATC controlled area and are below the transition altitiude the first thing ATC gives you is the current altimeter setting for his area. That way all aircraft are flying to the same exact altitude reference.

When you reach transition altitude which is 18,000 feet on your way UP to cruise all airplanes reset their altimeters to 29.92. This is so that all airplanes are set to the to the same exact reference for altitude. On long distance, high altitude flights it would be impractical to reset your altimeter to local barometric pressure because you would be changing it every 5 minutes. And there is no need. There is no terrain to be aware of hitting above 18,000 feet.

Now, on your way down you reset your barometric to local barometric pressure as given by ATC when descending BELOW Flight Level 180. An altitude in an airplane is called "Flight Level" when the altimeter is set to 29.92 (standard). In others words ATC will say to an aircraft cruising at FL240 something like, "United 654 cleared to descend and maintain one zero thousand feet, Chicago altimeter altimeter 30.14". So when United reaches FL 180, the 'pilot-not-flying' will automatically say, "altimeters 30.14". He will then set his altimeter, verify that the other pilot has set his altimeter and then say, "altimeters set and cross-checked' (He doesn't necessarily say "altimeters reset and cross-checked". It will depend on how that particular airline wrote their checklist). But the point of the excercise is to be sure that both the captains and the first officers altimeters were both set and checked to local baromeric pressure so that their altimeter is set to the same local reference as all the other airplanes.

The only reason I am in this thread is to see if the hijacker reset his altimeter on the way down. If he did, he was not a hijacker or the FDR was faked for these reasons:

(1) Who told him what the altimeter setting was? He wasn't talking to anybody. He definately wasn't on the right frequency. ATC occasionally broadcasts local barometric in the clear but it would be odd for that to happen exactly as the hijacker was passing through FL180.

(2) The hijacker is looking forward to his imminent death by crashing into the Pentagon. What the heck does he care what the altimeter says? Its not like he is going to perform an Instrument Landing Approach into the side of the Pentagon and needs to know what the exact intercept altitude is for the intercept.

(3) The hijacker flying a Boeing 757 for the first time, descending at 450 or 500 MPH trying to look out and see exactly where he his has his hands pretty much full. The chances that he would remember to reset the altimeter at exactly FL180 are non-existent. They are zero. And what is he going to set it to? He's not talking to anybody.

I am just getting into the thread so please let me know if it is determined whether or not the hijacker reset the altimeter on his way down. Thanks.

Thanks for the explanations! Very helpful!

As per your question on altitude reset:

Originally posted by johnlear
The only reason I am in this thread is to see if the hijacker reset his altimeter on the way down. If he did, he was not a hijacker or the FDR was faked for these reasons:

(1) Who told him what the altimeter setting was? He wasn't talking to anybody. He definately wasn't on the right frequency. ATC occasionally broadcasts local barometric in the clear but it would be odd for that to happen exactly as the hijacker was passing through FL180.

(2) The hijacker is looking forward to his imminent death by crashing into the Pentagon. What the heck does he care what the altimeter says? Its not like he is going to perform an Instrument Landing Approach into the side of the Pentagon and needs to know what the exact intercept altitude is for the intercept.

(3) The hijacker flying a Boeing 757 for the first time, descending at 450 or 500 MPH trying to look out and see exactly where he his has his hands pretty much full. The chances that he would remember to reset the altimeter at exactly FL180 are non-existent. They are zero. And what is he going to set it to? He's not talking to anybody.

I am just getting into the thread so please let me know if it is determined whether or not the hijacker reset the altimeter on his way down. Thanks.

I have no solid verdict yet. In fact it's impossible to know for sure ever, but...

- According to the animation as presented in PBB: no reset on descent, hence the cover-up.
- According to the pilots' obtained CSV "aa_77_Tabular," it was reset. (times and numbers, including "trim" - the 29.92-30.23 adjustment - listed in posts above)
- According to the FDR Specialists' study verifiably from NTSB, I'm not sure. Anybody feel free to scan it: www.ntsb.gov... I'll figure it out myself soon.
- Other sources, like the 9/11 Comm. and NTSB Flight path studies, I don't think reflect on re-sets at all, but I could be wrong.

I started this to verify correlation/"authenticity" of the relevant sources, but found this sort of underplayed argument inherent in the PBB video at least as compelling. But pending the results of my initial questions, the implication of this possible re-set must remain in doubt. Either way, I think the results will be interesting.

Originally posted by Caustic LogicEither way, I think the results will be interesting.

Hey CL... the results are interesting already!

There seems to be a discrepency between the animation and CSV file, right?

1) The whole point of the PF911T video is that the altimeter was *not* reset, and therefore the plane was much higher than the Pentagon. Or,

2) On the other hand, if the CSV shows the altimeter was reset, then the altitude would be correct at the point of the crash, but the pilots' claim re the NTSB video would be incorrect. Or,

3) The animation and CSV file are both fake.

What I did notice looking throug the flight path studies at the NTSB web site is that none of the studies show the altimeter graph jump going through 18000 ft., either up or down. Maybe it happens so quickly that the data isn't visible on the scale of the graph. I have no idea.