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The legal and political implications of 9/11 have turned scientific research in this area into a high stakes competition for the minds of the public. Pertinent information has been kept secret, the corporate media has systematically kept “damaging” information (such as video images of the World Trade Center Building 7) out of public view, 9/11 research has been marginalized, and the official investigations have failed to answer, or in many cases even address, the most troubling questions. One development that appears to be a tactic in the ongoing cover-up is the high profile promotion of transparently false theories, “straw men,” the only purpose of which appears to be to allow the 9/11 Truth Movement to be ridiculed.

With the tenth anniversary of 9/11 upon us, the battle for public perceptions has intensified and there is a heightened campaign to undermine the scientific basis of the truth movement. Dr Judy Wood has published a book asserting that the World Trade Center (WTC) towers were felled by “dustification” of the steel, which she claims is achieved by the use of “directed free energy”.[1] It is, however, obvious that the steel was severed and fell in normal lengths, otherwise intact, as seen in conventional demolitions. The similarly foolish idea that the WTC towers were demolished by nuclear explosives, long ago refuted,[2] has also been recently revived, with a new claimant appearing, Jeff Prager,[3] but this appears to be having little influence so far. No explanation involving “directed free energy” or nuclear devices could account for the way separate explosions appeared in the Twin Towers, layer by layer, descending at a precise rate, as the towers came down.[4]

It is important to distinguish between devious false claims, intended to weaken the truth movement, and false claims which result from accidental errors. There can be errors of interpretation of evidence, calculation errors and misleading testimonies from witnesses who fail to correctly remember the event they observed and describe.

An example of an unfortunate calculation error is found in the work of Pilots for 9/11 Truth (PFT). This group has a long-held position that the topography near the Pentagon would rule out impact by American Airlines Flight 77 (AA77). This position was based on a calculation that the plane would necessarily experience an unsurvivable force of 10.14g if it attempted to pull up from the dive on approach to the Pentagon.[5] PFT based its calculation on a path that was somewhat different from the path of the plane as shown in the files initially provided by the National Transport Safety Board (NTSB), reportedly from the flight data recorder (FDR). The NTSB data appeared to show that the flight terminated at a point too high to have hit the Pentagon. Instead, to make the possibility of impact more feasible, the PFT calculation was based on the assumption that the plane actually came in much lower, level with the top of the VDOT antenna tower near the Navy Annex. It was shown by several researchers that this calculation was incorrect due to a substantial error in determining the radius of the pull-up arc. This error, in turn, produced an excessive value for the required g-force. The error was increased by assuming, without evidence, that the plane traveled in a straight line at a constant descent angle from the top of the antenna to the first light pole hit. If this artificial restriction is removed, and the plane is allowed to follow a curved approach, the pull-up can be spread over a wider arc, increasing the radius of curvature and reducing the wing load. Calculation shows that paths can be found such that the force generated would place no undue stress on the aircraft, being well below the design limit of 2.5g.[6]

The file provided by the NTSB certainly appeared to show the plane was not only too high to strike the Pentagon but also was descending too steeply to have produced the type of damage observed. This behavior suggested to some researchers that the recording of data had been terminated while the plane was still on descent. John Farmer used radar data to check the FDR file data and concluded that indeed several seconds of data was missing from the end of the file.[7] Recently Warren Stutt discovered that there was one more frame of data at the end of the FDR file which had not been decoded previously. He wrote a decoding program and managed to extract a further 4 seconds of data. This data includes radio height above ground, which now shows the plane descending smoothly, pulling up safely and hitting the Pentagon close to the ground, in accordance with the majority of eyewitness reports.[8] PFT is not willing to use this data as there is no proof that the file is authentic and has not been tampered with.[9] Despite claiming that the file cannot be relied upon they use it to claim that the final radio height was measured from the Pentagon roof as the plane flew over. It has been shown that this argument is not correct as the prior data points do not reveal a sudden jump upward of the reflecting surface as the Pentagon is reached.[10]

It is further argued by PFT that the radar data must be in error as it does not correspond with the pressure altimeter record, which still shows the plane too high to hit the Pentagon. On approach to the Pentagon, however, the plane is flying much faster than normal for an aircraft at low altitude and so would be operating well beyond the calibration envelope for the altimeter. It appears that, at least on this particular plane, a substantial error is produced, increasing as the plane accelerates and descends. In contrast the radio height would not be affected by speed. It is therefore reasonable to accept the height it shows, which corresponds with the height shown by the damage to the light poles and the face of the Pentagon. This has been fully discussed in a previous paper where it is shown that the altimeter reading and radio height reading correspond closely with each other at normal altitude and speed but diverge as the plane descends and accelerates to abnormal speeds.8

One of the reasons why PFT may be reluctant to utilize the newly decoded last frame of data in the FDR file is that the concept that the plane could not have hit the Pentagon, and therefore must have flown over, is supported by the Citizen Investigation Team (CIT). In this paper we examine the flyover theory presented by CIT and find it to be false.

CIT claims (1) that the plane approached the Pentagon along a path too far north to have done the observed directional damage, (2) that all the damage was faked and (3) that the plane flew over the Pentagon. The apparently surprising claim that the plane flew over the Pentagon is a necessary part of the CIT position as it explains the lack of damage in alignment with the north path inside the Pentagon. CIT supports its theory with the testimony of a small number of selected witnesses, presented in selectively edited video interviews, who state that the plane passed north of the former Citgo service station.[11] David Chandler and Jon Cole point out, among other things, that the CIT “…witnesses are not representative of the overall eyewitness pool”.[12] Certainly their witnesses are not representative of the witness pool as there are very many more witnesses to impact.[13] Gregg Roberts states that CIT’s work contains “logical fallacies”.[14] CIT disputes the findings of Chandler and Cole at length[15] but provides no new evidence, and has intensified its personal attacks on anyone who criticizes their claims in blogs and Facebook. We do not assert that CIT is deliberately setting up false theories in order to expose the 9/11 Truth Movement to ridicule, but that is likely to be the ultimate effect of their efforts.

Unfortunately the well presented videos and website of CIT have impressed a lot of people, so dissension has arisen, which is destructive to the 9/11 Truth movement. Michiel de Boer has suggested that the accumulated evidence that a large commercial aircraft hit and damaged the Pentagon is now so substantial that we should plainly assert that impact did occur.[16] The natural corollary to the proposition that impact occurred is that the claimed north path, and consequent overfly of the Pentagon, is false. The physical implausibility of the north path proposition will be demonstrated in this paper.

Consideration of prior events

During the morning of 9/11 four planes were hijacked and the normal interception response failed. Two of these planes hit the WTC towers. These impacts were seen by many people and recorded on video. It cannot be rationally disputed that they occurred. The impact on the South Tower was recorded on several videos showing that the plane largely penetrated the building. Very clear photographs of the impact areas of both towers exist and it is clear that all but the wing tips entered the buildings. Some debris fell to the street below and was reported by eyewitnesses and photographed. The amount was small and appeared commensurate with the portion of the impact area not penetrated.

In the case of the Pentagon the outer wall had been reinforced to an unusual degree during renovation so it appears reasonable that the impact hole would be smaller and that more of the plane would fail to penetrate the building. Photographs and videos show the entire wingspan of the plane damaged the face of the building but the entry hole was smaller. On the ground outside the Pentagon a substantial amount of debris was observed and recorded in photographs and videos. Again the amount of debris outside appeared roughly commensurate with the portion of the impact area not penetrated.

As two incidents had occurred that morning in which planes had been observed to deeply penetrate buildings, it should not have been surprising that a plane could penetrate the Pentagon, and there was initially general acceptance of the impact report. Unfortunately, however, a number of observers saw the debris outside the Pentagon but did not see the sizable hole in the wall, more than adequate to allow most of the aircraft to enter. They reported that the amount of debris was not sufficient. Thus was created the fertile field in which alternative theories developed to explain the observed damage.