ABC - 13:03:00 UTC (time stamp changes at the moment of impact)
CBS - 13:03:01 UTC
CNN - 13:03:01 UTC (time stamp changes at the moment of impact)
FOX - 13:02:55 UTC
NBC - 13:03:01 UTC

For those without broadcast time-stamps, the tracking counter + video start time was used. 13:03:01 UTC seems to be the upper and most reliable estimate of broadcast time.

Using the last two returns for UAL175 in the 84 RADES data, I calculated the last known speed as  797 feet/sec. After the final return at 13:02:24 UTC, there remains 11,022 feet of flight left.  Using simple arithmetic, 14 seconds is a reasonable estimate of time-until-impact, giving the most probable impact time of 13:02:38 UTC. This gives a time difference at the upper bound of ~23 seconds. This number will become a significant factor in later posts.

The time of impact determined from FAA radar was 13:03:14 UTC, while William Scott testified before the 911 Commission on May 23, 2003 that “the impact time was 9:03:11 based on our analysis of FAA radar data and air traffic control software logic.” The FAA estimates are the most notable and will be explored further in my next post.

The image above is a composite of the 84 RADES, RO2, IAD, DCA, and ADW positional data for AAL77. The data sets agree with one another with expected variation between the sets.

There is a time difference observed between the DCA/ADW data and the IAD and BWI data on the order of a few seconds which I will be exploring further. The following azimuth offsets were used to convert to spherical coordinates.

DCA/ADW = -9.5 degrees
IAD = -10.0 degrees
BWI = -10.5 degrees

The BWI value has not been tested completely and is a rough estimation. If readers note any irregularities in the BWI offset, please let me know so that I can correct it. The others have been tested extensively. The files are available together in one Excel file, or individually as csv files.

Excel Workbook
DCA csv
ADW csv
IAD csv
BWI csv

My next effort will be a time study for the respective data sets using common aircraft similar to past efforts.

http://www.youtube.com/watch?v=VF5bN6er5TQ

Note: This data matches the 84 RADES path for GOFER06. It is a mix of DCA TRACON radar data and the TYSON ATC audio. I will upload the full version (better quality) to AAL77 later today.

Full version: http://aal77.com/movies/DCA_TYSON.avi (70 mb avi)

http://cleartheskies.com/rebuttal.html

The CMH FOIA is now completed. I have 7 written interviews to scan and 13 audio interviews on cassette tape. These will take some time to complete uploading to the site on my part due to the sheer volume of stuff coming in recently.

I’ve heard some critics say that I want to vent stuff before uploading. Well, the fact is this project is costing a lot of money and time and it only seems right that people who have contributed to the cause get first crack at what they paid for. The folks who just sit in front of computers and complain will just have to get in line.

Update (9/23/2008):

I have completed updating the FAA folder with everything I have. Enjoy!

http://aal77.com/faa/faa_foia.php

I developed a graphic to summarize the derivation of the special equation for centripetal acceleration. I will develop this into its application as a vector component later as I fully develop the force vectors involved in calculating the applicable g-forces.

Using a circle as a reference, it is important to note that the equation used by P4T is a special case solution valid ONLY when r₁ = r₂ and v₁ = v₂. The solution also assumes that the trajectory is circular, a discussion I will save for later. Unfortunately, I will have to use calculus to fully develop the solutions to this problem, but I will attempt to keep the math as simple as possible. The reader needs at this point to familiarize themselves with the notations for velocity and acceleration. Velocity (ds/dt) is the first derivative of distance (s) relative to time (t), while acceleration (d²s/dt²) is the second derivative.

Of importance is that the direction of the centripetal acceleration is towards the focus (inward) of the circle.

At question is the “impossible” g-force scenario that P4T speculated on in a previous work, “Arlington Topography, Obstacles Make American 77 Final Leg Impossible” posted at 911Blogger.com. As a result, I did a review of his assumptions and premise:

The heart of his [Rob Balsmo] argument is that extreme vertical acceleration forces required by that trajectory exceed the specifications of the aircraft to a degree that makes the final pull-up maneuver “impossible”.

In general, this review was a follow-up on a post done here at 911files.info which challenged the math used by P4T in making such a dogmatic assertion. In the new video, P4T asserts that I initiated the one-dimensional analysis of the g-forces, which is a blatant falsehood.

The first thing that must be understood is that what is impossible is to accurately determine the instantaneous acceleration forces acting on the plane during this interval because the RO2 output ends well west of the interval to be studied. So the best that can be hoped for is to determine an average acceleration which will be exceeded along the interval at various instances. The actual solution is a curved one, not linear. Unfortunately, not enough data exists to determine the exact altitudes and positions required to calculate the inflection points (points of maximum and minimum acceleration). So the best that can be done is to develop a simple linear model which will predict the average acceleration change for the given interval.

So, my response was to give a very simple linear model based on P4T’s assumptions and indeed, their physics was found to be flawed at best. This is acknowledged by P4T in their new video, crediting Lt. Col. Jeff Latas with discovering their error. This too is disinformation, because their error was pointed out in detail here at 911files.info.

In the video, P4T compounds their error by asserting that critics (including 911files.info) used simple one-dimensional formulas to rebuke the P4T errors. They demonstrate a complete ignorance of physics when they fail to realize that Newtonian physics applies just as well to a car as it does a plane. What differs is the complexity of the problem and orientation of the vectors. Critics simply responded to the argument made by P4T, and did not engage in correcting their approach. This does not negate the results however, because in the case of my analysis, it is a valid evaluation of “vertical acceleration forces” which was the original problem.

P4T now asserts that the solution is invalid because it is a one-dimensional solution. Indeed, the discussion was initiated requiring a solution for F_z by P4T. In their new video, they now claim that it is a two-dimensional problem, not a one-dimensional one. That too is a failed assumption, because the actual problem requires a solution for the sum of three force vectors, not two. Further, such a solution is asking for a solution of the second-order differential of a three-dimensional problem. Such a solution however is a complex one, and each of the force vectors can be solved individually for simplicity sake, which is the premise of the first discussion which P4T failed miserably at. Now, without even fully grasping the significance of the physics of a one-dimensional solution, they are attempting what they call a “two-dimensional” one.

In the new video, P4T presents an equation for centripetal force as the “solution” for this new “two-dimensional” problem. I will be doing a full review and analysis in the weeks ahead just to put this to rest once and for all. In the meantime, P4T fails to understand parabolic motion and that is their first error. They also fail to understand simple Newtonian physics and force summation. This is demonstrated when they derive a value for the centripetal acceleration and then ADD the downward force of gravity to the result. The force vector of one g is in ONE direction, down. First step is to determine the direction of the centripetal force vector and then calculate the segment of the g vector that is opposite to it. Then, the two forces are OPPOSITE of one another and are subtractive, NOT additive. What you are attempting is to find the sum of the normal forces acting on the aircraft at a particular instant in time.

The sad thing is that most of the general public is not physics or math literate enough to catch the obvious errors in the latest P4T fantasy peice. I will attempt to keep my full review of this new “solution” as simple as possible, but I’m afraid it will require more than “high school” physcis to properly vent. I’ll give them a few weeks to go read some good physics and calculus textbooks so that they will be ready for the discussion.

I guess I have been around enough police officers and fishermen to know how “war stories” grow over the years and take a life of their own. In high stress situations like those experienced by all on 9/11, the center of focus for most is on what they are experiencing and there is often a very self-centric aspect to such recollections. This is what I have warned about over the years to those who rely solely on eyewitnesses for a reconstruction of events. Lynn Spencer’s book is devoted to telling the stories of those who were there, from their point-of-view. In that respect I learned a lot from it, but I keep them in the proper context.

Unfortunately, Ms. Spencer took aim at the 911 Commission with her book and that is unfortunate. Several members of the Commission took the time to respond to several aspects of the book as a result. I happen to agree with the 911 Commission staffer’s position. A few weeks ago, a reader asked me to evaluate Billy Hutchinson’s account and I found it accurate in some respects, but no evidence that he had acquired UAL93 on his radar (he was not up over DC until almost 45 minutes after UAL93 went down). While I was in Arlington last week, I took Ms. Spencer to the side (although I emailed the data to her as well) and expressed my concerns about this time conflict. She even acknowledged the time conflicts in her lecture later. There will also be further timing issues addressed in Mark Gaffney’s new book, the 911 Mystery Plane.

However, I am not willing to “throw the baby out with the bath water”. Ms. Spencer’s book is an important and well-done contribution to the body of knowledge regarding the events of 9/11. She did not have the advantage of the 84 RADES data or the recent FAA releases with which to validate information provided by witnesses. I have also had the privilege of not only being able to discuss this with her, but also with one of the article’s authors (after the op-ed’s release). What those who served on the 911 Commission forget is, the information they had to work with has been denied to the public-at-large. The rest of us have had to rely on the few small media segments that are out there. The government has been very evasive and secretive regarding data and documents which the public needs to properly evaluate the functioning of their government on what was perhaps the most significant historical event of our lifetimes.

So lets not be so quick to criticize Ms. Spencer or the 911 staffers. As someone who spent months assisting Mr. Gaffney with his book, I can tell you that by the time his book’s deadline approached, new information came forward that resulted in numerous re-writes before the final draft went to press. I am sure that by the time it hits the bookstores, even more information will become available.

I for one am glad Ms. Spencer took the time to document all of the first-hand accounts that she did. I am also very glad to see the article which clarifies some of the timing issues resulting from the government withholding data. She had FOIA requests in for the data, but until Pinnacle pushed hard through his Congressman, and I took them to Court, the FAA simply was not going to make that data available. So perhaps now with more coming into the public domain, we can write a better history of those events.

John, have you seen this?
http://www.nytimes.com/2008/09/14/opinion/14farmer.html?_r=1&oref=slogin

It’s by the John farmer that was a staff member on the 9/11 Comm, and makes a similar point to what you made here:
http://911files.info/blog/?cat=22

Some people will now wonder if you’re the same person, listed here http://www.freerepublic.com/focus/f-news/1462578/posts
as
“Senior Counsel. Former Attorney General of the State of New Jersey and Chairman of New Jersey’s Domestic Preparedness Task Force in the aftermath of September 11.”?

In fact I started wondering the same, except that would mean you went deep cover in all but name…

No, I am not this John J. Farmer, Jr. I am this John Farmer. As far as I know, we are not related in recent generations, but I do suspect we are both of Scottish descent. I don’t think the other John Farmer wears Mickey Mouse ties either, but I could be wrong. That John Farmer is an Ivy League type, and I am just a lowly redneck from Tennessee. So, please, enough of the rumors already.

http://aal77.com/arlington_county/lynn_spencer.mp3