9-11: Impact Times; Infra-red Data Released by NSA

Addendum October 9, 2014

This addendum makes one correction and adds a PDF of my May 15, 2014 appeal letter. Based on the date of that letter it took NSA not quite five months to reconsider. Here is a link to my appeal.

IR Appeal Letter May 2014

Data Release

On October 4, 2014, I received a letter from the National Security Agency, Central Security Service, dated September 23, 2014.  The letter responded to Mandatory Declassification Review (MDR) case 70401 (NARA case number NW 168), my appeal to an earlier complete denial of all infra-red related information.

The release authority has now provided graphic analysis of the data for all four impacts, as originally provided to the Commission. The times, in all cases, are consistent with the times established from radar files and air traffic control tapes.

Here is the transmittal letter for the information release.

NSA MDR Letter Sep 23 2014

I addressed the total denial of all infra-red related information in a short post on March 25, 2014 under “Current News.” It took just over six not quite five months for the National Security Agency to reconsider. I based my appeal narrowly, asking only for the infra-red impact times, and nothing else. That is perhaps a lesson learned  for researchers and historians, present and future.


The 9/11 Commission Staff requested infra-red data concerning the impacts of the four hijacked airplanes on September 11, 2001.  The staff took that extra step because an analysis of seismic data by a separate individual reported a impact time for United Airlines Flight 93 three minutes after the 10:03 EDT impact time as determined from radar files and air traffic control tapes.

It is important to know that the later time, 10:06 EDT, was not a seismic data time. It was the extrapolation and interpretation of seismic data by a single individual. His coauthor and the sponsor of his article, the Maryland Department of Natural Resources, chose not to validate and verify his work when asked to do so by the Commission Staff. Instead, they simply referred the Staff back to the person who had made the extrapolation. I addressed the seismic issue in detail in an article published in 2010.

In 2011 during a visit to the National Earthquake Center, Golden, Colorado, I informally asked the staff there to take a look at the interpretation that led to a time of 10:06 EDT. They, too, declined, and simply referred me back to the original author.

The Staff Request

The original request is “Document Request No. 4-34: Final data from the Defense Special Missile and Astronautics Center (DEFSMAC) that established the time of impact for each of the hijacked aircraft.” The response to the Commission was classified “SECRET//X1” and was titled (U//FOUO) NSA’S ANSWERS TO DoD DOCUMENT REQUEST No. 4-34.” The response is annotated NW#: 168 DocId: 8977.

The Response

There are two graphs that are accurate to the minute and the approximate seconds for each impact, if extrapolated. The following chart depicts my current extrapolations. The intensity measurement is in Kilowatts per microsteradian (KW/sr-μ).


Impact Time


AA11 8:46:30+/- 250 KW/sr-μ
UA 175 9:03:10+/- 3500 KW/sr-μ
AA 77 9:37:30+/- 900 KW/sr-μ
UA 93 10:03:10+ 2000 KW/sr-μ

One graph depicts the times for all planes except UA 93. A second graph pertains to UA 93 and incudes a peak intensity time centered on 10:03:16-17+, and a dissipation time of 10:03:25+  Peak intensity was recorded as 5000 KW/sr-μ.  That graph provides an approximate measure of the time the fireball was observable, a period of about 15 seconds.

There is no data to indicate that DEFSMAC considered peak intensity for the other three impacts.

I do not recall making an extrapolation while on the Commission Staff. It was clear from the graphs provided that the infra-red times were consistent with other primary source data.  In particular, the infra-red data was conclusive for a 10:03 EDT impact time for UA 93, not 10:06 EDT, as had been speculated.

Here is the graph titled: “Aircraft Impacts – NY & DC, 11 September 2001 – IR Intensity vs Time (Zulu)

IR impact times AA11 UA175 AA77

Here is the graph titled: “Impact of United Flight 93 – Pennsylvania, 11 September 2001 IR Intensity vs Time (Zulu)”

IR Data UA93


This completes my work on all speculation that the seismic extrapolated time is relevant to the impact on UA 93. It is not, now, and never was. All such speculation is based on the work of a single individual who informed the Commission Staff that the seismic data, itself, was not conclusive.

At some future time a scientist or engineer will examine the original raw data—seismic, radar, and infra-red—and will find that the three data sets are consistent.