Analysis of Flight 175 "Pod" and related claims

by Eric Salter
with contributions by Brian Salter, 9 September 2004


The 767 wing fairing vs. the "pod"
The "bomb"
Head-on angle shows no evidence of the pod
A "missile"
Spanish cylinders
The "flash"
A cargo plane?
Conclusion, run by Phil Jayhan, and others claim that there was a pod on the underside of Flight 175 that fired a missile as the plane entered World Trade Center 2. I have to admit that initially looking at the images of Flight 175, I was open minded about this claim. It certainly seems at first glance like there's a pod, and it doesn't suprise me that someone would come up with such a conjecture. But with further research, I have grown increasingly skeptical and believe there is a simpler explanation for these images.

The 767 wing fairing vs. the "pod"

The fuselage bulges out where the wings join it. This is called the wing fairing. The landing gear assembly folds into this area when it is retracted, which is seems to be a problem if the alleged pod is a missile launcher:

As is clear in comparing the photos above, under the right lighting conditions the wing fairing can look more pronounced. Notice how the reflected sunlight (specular highlight) on the right side of the plane in the center photograph changes from the fuselage to the fairing. This will be important later.

The alleged pod appears in video footage from CNN, Evan Fairbanks, and Pavel Hlava, and in Carmen Taylor's digital photo.

It's not unreasonable to say that it looks like there's a pod on the plane, but the question is, could this be an optical illusion? There are two possible culprits to examine: reflections and shadows on the plane. First, the possibility that the surface of the wing fairing is not illuminated, creating a dark area that could look like a pod.

In the following photo, the sunlight is weaker and more diffused than on the morning of 9/11 so the contrast between highlight and shadow is not as deliniated, but there are similarities to the Fairbanks footage. The entire right side of the fuselage is illuminated while the fairing on the right side of the plane is still dark. But the sunlight here appears to be shining from slightly behind the plane, instead of from slightly in front. There is one key difference: the right wing is dark here, and illuminated on Flight 175. So the question is, could the underside of the fairing remain in shadow while the wing is illuminated?. Looking at pictures of 767s on the ground, the angle of the wings appears to be roughly parallel to the undersides of the fairings and that would seem to make this impossible. However the angle of the wings, the wing dihedral, increases somewhat when the plane is airborne. And because the 767 was making a high speed turn, the wings would have bent up even further then is normal than in level flight. This might allow the underside of the wing to be illuminated while the underside of the fairing remains dark.

In the following photo of a 767 there is a difference in the angles of the wings and that of the innermost part of the wing fairings. However, the measurement of the angle of the fairing surfaces was made by looking at horizontal linear reflections on the fairings, so it should be considered a rough measurement. That said, I can't see any reason to argue against the assumption that, at a certain angle, it is possible for the wing to be illuminated while the fairing remains relatively shaded, especially if the wings were bent upwards even further than normal because of the high speed turn Flight 175 was making at the time.

The plane in the Fairbanks and Hlava footage is quite blurry and it's not easy to analyze. The source for the Fairbanks footage analyzed here is a DVD, so even the original footage won't look that much clearer than what we have to work with. The source for the Hlava footage analyzed here is an MPEG4 found on the web, so I'm not sure what the quality of the original video is. In that MPEG4 movie, there is a video artifact called "ringing" affecting the image. This was present in the video before it was compressed for the web. It is a result of signal degradation through dubbing or broadcasting, although it may also be present to some extent in the original footage. Notice how on the vertical edges between light and dark areas, such as the right wing or the edge of the building, there is a sort of ghosting effect that adds a black halo. This is ringing. Also notice where the ringing happens, such as the edge of the smoke cloud, it appears to be somewhat rounded or raised. Ringing would be created by the transition from the shaded fairing to the illuminated wing, and may be causing the fairing area to take on the more of the raised appearance of a pod. One more note about the Hlava "pod": it looks thinner and straighter than the "pod" in the CNN or Taylor images, in which it appears more rounded. I don't think foreshortening due to perspective could cause this difference, because the angles of view of the plane are not that different. This should be factored in as supporting the optical illusion hypothesis.

Looking at the CNN and Taylor images, there are a couple things that might help create the illusion of a pod. The stripe-like reflection that runs down the left side of the fuselage is interrupted by the fairing on the left side. This might appear to some to be a shadow cast by the pod. Remember this reflection is caused by light coming up from below and could not be interrupted by any shadow from the pod. The second observation I would make about the CNN and Taylor images is that the innermost flap on the right wing is brightly illuminated. This may be helping to create what looks like the bright right edge of the pod. In each image there is a small portion of the bright area next to the fuselage which does not seem to be part of the flap. This could be part of the wing fairing catching the light. But there may be another explanation. The CCDs in video or digital still cameras react poorly to very bright highlights. Notice in the Taylor photo how bright highlights on the engines have flared out into round blobs. The highlight is "blooming", expanding beyond it's size in real life due to the nature of video technology. The highlight on the flap may also be blooming, causing it to overlap onto the fuselage.

Linear reflections on the fuselage are clearly visible in the CNN and Taylor images. These reflections could contribute to the pod, but before analyzing these images, there is another photograph which more clearly demonstrates how these reflections could be responsible for the appearance of a pod. Recently, Letsroll911 has posted a newly acquired black and white photograph of Flight 175:

Once again, the pod appears to be there. Not only does the right fairing appear to be more raised, the left fairing, on the bottom, appears to be shorter. But notice that the two linear reflections that run down the fuselage are not equidistant from the midline of the fuselage. The one on the side of the alleged pod, labeled "highlight 1" is further towards the top of the plane. Therefore these reflections intersect the wing fairings at different points, and when they intersect the fairings they change shape or disappear, as we would expect:

Highlight 2 is longer because it intersects the wing fairing further down the fuselage than highlight 1. I've outlined in yellow an estimation of the path of each reflection. That highlight 2 stops while 1 continues is a result of the angles of the reflecting surfaces in relation to the light and point of view of the camera. The shape of highlight 1 is very similar to the shape of the highlight in the center image at the top of this page. In the end, there is nothing anomalous in this photo that can't be explained by reflections of light on the fuselage.

Like the black and white photo, the asymmetry of the shapes of the left and right wing fairing areas in the CNN footage and Carmen Taylor's photo is also probably caused by the differing positions of the reflections:

The "bomb"

One more note on the black and white photo. Jayhan claims that there is a bomb fixed to the left engine of the 767. This is an illusion created by the engine mount, the ridge-like part that goes over the flap (I don't know it's name) and a dark area of shadow between those two parts. Also, there is no sign of a bomb in the CNN footage.

Head-on angle shows no evidence of the pod

Another problem with the pod theory is that there isn't a pod visible in this piece of footage from CNN's DVD of 9/11:
CNN WTC2 strike looking south
For this movie I've zoomed in to the plane and stabilized it in the frame. The only thing that protrudes beneath the plane is the end of the fuselage, dipping down as the plane tilts up. However, the plane is rather small in the frame and not very well in focus, so this footage is not quite conclusive:

A "missile" identifies a cylindrical white shape on the side of flight 175 as a missile. The source for this analysis is a movie taped off Spiegel TV of Germany. Overlaying the outline of the plane on the footage, it's clear that this shape is not making forward progress in relation to the plane, and in fact is remaining in the exact same position. It is a reflection of sunlight on the plane's fuselage.

Letsroll identifies a highlight on the plane in footage shot by Park Foreman as the same missile, even though it is a different length and in a different position on the fuselage:

At the beginning of the clip the sun's reflection is at the nose of the plane. It disappears while the plane is under the smoke cloud, then reappears in the middle of the fuselage because of the change in position of the plane in relation to the sun. The wing interrupts the reflection. Looking at the last 6 frames, which are from the half second before impact, the reflection stays in pretty much the same place, which should make it obvious that it's not a missile or missile exhaust. The difference in shape and position of this highlight between the Spiegal TV footage and Park Foreman footage is the key to identifying it as a reflection of sunlight. Here is another 767 with a specular highlight interrupted by the wing fairing:

One difference between professional file photos of 767s and the images of flight 175 are the reflections on the underside of the fuselage. Airport runways are a mostly a wide field of the same brightness, whereas flight 175 was reflecting a high contrast image from the city below, a mixture of light and shadows from the buildings in the morning sun. One of the reasons the underside of flight 175 seemed metallic instead of blue was because of the contrast of light and dark in these specular highlights, something that our mind normally associates with metallic surfaces. With a higher contrast in the reflections, there is more of a chance for the creation of an illusion of a protruding object on the plane. Letsroll and others have misidentified reflections as pipes or other cylindrical objects on the plane's surface.

Here are some examples of how reflective cylindrical objects reflect light:

The reason the linear reflections don't extend the full length of the plane's body as they do on these objects is because the ends of the fuselage are tapered, changing the angle of reflection. Otherwise, it should be obvious that the linear patterns on the 767 are the same sort of reflections of light and shade in the environment that we see here.

Spanish cylinders

A newspaper in Spain published a article that concluded that there were cylindrical objects on the underside of the fuselage, in addition to the pod. It referenced an image analysis done at a Spanish university. Although the analysis uses a lot of fancy terms, it doesn't stand up to scrutiny. They identified images in which "cylindrical objects" are visible on the plane and applied filtering:

The objects are on the left side of the fuselage in the first shot, and on the right side on the second. We should see the right hand cylinders in profile in the first image but we don't. Nor do we see them on the plane at the beginning of the Park Foreman video. One would think that someone working at a university level would be able to figure this out. The study goes on to compare these images to other photos of 767s taken under totally different lighting conditions. Not surprisingly, no cylinders are found. This "university study" does not rise to the level of university research. The supposed cylinders on the fuselage of the plane are so obviously specular highlights that I'm inclined to think that this is either a practical joke or disinformation aimed at those who are not technically or visually astute.

The "flash"

A flash appears in 4 videos-the CNN, Spiegel TV, and Evan Fairbanks footage and an unidentified source from the In Plane Site DVD:

In the CNN footage the flash lasts for one field, or 1/60 of a second. In the Fairbanks and unidentified footage it extends over two fields. Judging by the Fairbanks footage, it looks as though it might be extending out from the surface of the building.

There have been some claims that the flashes occured just before the impacts. I think these are erroneous; the South Tower flash is clearly timed with the contact of the nose with the building, which can be verified by carefully following the movement of the nose of the plane leading up to impact. In the case of the North Tower flash, which is visible in the Naudet brothers' footage, the plane's shadow (extending down diagonally to the right) meets up solidly nose to nose with the plane immediately before the flash. Therefore, this flash also occured at the moment of contact, at least to the degree that one can be certain based on the low resolution of the footage:

In the case of the south tower, In Plane Site and others have claimed that there is a gap between the fuselage and the flash, using the Spiegel TV footage to support this. But keep in mind that the building casts a very slender shadow over the front part of the plane as it enters. The shadow can be seen over the front part of the nose when the flash occurs in the Fairbanks and Spiegel footage, and can also be seen on the wings and engines in the CNN footage. Notice in the CNN footage how the left engine loses it's highlight just before entering the building. The appearance of a gap was probably caused by the shadow of the building on the fuselage. As part of their analysis, In Plane Site argues that the reflection of the flash can be seen on the fuselage, but this may be the tail end of the reflection of sunlight seen in earlier frames (it's shape slightly changed from flexing in the skin of the airplane due to the impact.) Or it may be a combination of both, with the reflection of the flash (which would be less intense than sunlight) on the shaded part of the fuselage obscured by the intense ringing effect from the highlight (the ringing is the dark blob in between the highlight and the flash).

There have been some accusations made that the flashes have been added to the footage via digital manipulation. I do not agree with these accusations of forgery. The flashes show up in various versions of the footage from different sources, including mainstream commercial releases. The only versions of the footage that I have seen which do not have the flashes are conversions to digital files, in which the flashes can disappear due to de-interlacing (a normal part of the conversion process) in the case of footage where they only persist for one field (half of a frame). Keep in mind also that certain types of slow-motion and image enlargement processing can make it appear that the flashes have been enlarged or lengthened. The site, making an implied accusation of forgery, claims that there is no flash in the video "The Great Deception" released by Barrie Zwicker back in 2002, but I looked at the video and it was indeed there.

Letsroll identifies the flash as the exhaust of the missile entering the building. The problem is we don't see a missile and there is no smoke trail visible. If I had to speculate on what weaponry could cause this, I would be more inclined to propose some kind of energy weapon. has an analysis by Mario Andrade that speculates that the flash is light and flame emitted by a general purpose bomb with a nose tip fuzing system equipped with a delayed timer:

I'm at a loss to analyze this as I don't have experience in relevant fields. I have several comments, however. My first would be that it doesn't appear to be a jet of flame shooting forward, so I wonder if this is really what the effect of the fuze would look like. The bomb shown in the diagram doesn't have it's own means of propulsion, so I'm curious how it would get from the pod to the front of the plane. Was it spring loaded in the pod? In any case, there is no bomb or moving weapon visible. The fact is, there is really no reliable visual evidence to directly support a connection between the flash and the existence of the alleged "pod". This is the really crucial point.

In Plane Site claims that the flash represents use of an explosive device which was required to act as like a match to ignite the fuel into the subsequent fireball — without offering any further explanation. The first question that came to my mind after hearing this was, since when do crashing airplanes need such assistance to cause their fuel to ignite?!! I suppose, then, that every other fiery airplane crash in history must also have featured the use of one of these secret devices.

Beyond this, many more speculations could be offered. Perhaps some explosive weapon was triggered from inside the cockpit, or was hidden in the nose cone. Perhaps, although this might be a stretch, the flash could be a result of a massive static discharge as the aircraft hits the conductive surface of the tower (metal-skinned airplanes of all types can build up very large electrical charges during flight; normally, these are dissipated gradually through special external attachments known as static wicks, but under the right circumstances, a sudden uncontrolled discharge can be as powerful as a small lightning bolt, and occurences of this kind are on record). Alternately, some people argue that the flash was just a shower of sparks as the plane collided, metal on metal, with the building. Neither of these hypotheses would seem to account for the especially bright North Tower flash, however. Eric Bart speculates that the North Tower flash might indicate the use of 'shaped charge' explosives:

A simpler speculation might be that the impact twisted one of the WTC outer wall panels out of place in such way that it momentarily reflected a glint of sunlight off of the glass and/or aluminum facing. Admittedly, this would be a bit of a fluke, but can it be ruled out?

Ultimately, there are only speculations at this point concerning the flashes, and I definitely do not claim to have the answer. Undoubtedly, any attempt to explain things further must be backed up with expert testimony from people with the right expertise in explosives, engineering, etc. Regardless, in the case of both flashes, the visual record is so limited that I seriously doubt that any definitive explanation will ever be found, so one must weigh the risks and benefits of delving into a potentially irresolvable are of speculation which may not be guaranteed to help break the overall case of 9/11. Still, the flashes could be a reason to be open minded about the potential that there was more going on with these two planes and the impacts than the official story admits.

A cargo plane?

Letsroll and In Plane Site claim that the 767 has no windows and is therefore might be a prototype KC767 fuel tanker. This is not a credible claim, being based on photos in which the windows are as small or smaller in size than the noise or grain in the image. The windows shouldn't be visible to begin with at this level of detail. Notice in the second photograph that the cockpit windows, which are twice the size of the passenger windows, are themselves barely visible. Also note that in the first photo on this page at the top left, the windows are not very visible despite the fact that it is a much sharper photo.

(There have been claims that the two lines on the bottom of the fuselage in the photo above is fuel being purged from the KC767 tanks. The most obvious problem with this is that we don't see it in any of the other images. Also, the speed of the plane would have caused the fuel spray to be swept back at a much sharper angle. A much better explanation is put forward by Mark Hungerford, who identifies these as blade shaped antennas on the bottom of the fuselage. Because the antenna are flat, they would reflect sunlight only at just the right angle, which explains why they are clearly visible only in this photograph.)

Seeming to back up the claim of no windows, In Plane Site features an apparent interview (audio only) with a Fox News reporter who claims that the airliner looked like a windowless cargo 767. He also claimes that it had markings clearly different than United Airlines, including an unfamiliar round symbol on the nose. This immediately presents a problem, because it is clear enough in the left photo above that the airliner is indeed painted in the UA color scheme -- even the narrow red stripe down the side of the fuselage can faintly be discerned. No errant large logos are visible, certainly not in either of the above two photos, nor in any other photos or footage I have seen. On top of this, this witness also happens to mention that he was in Brooklyn! This would put him at more than a mile away, or more, from the WTC. This leaves something to be desired concerning the reliability of this one-of-a-kind report, to put it mildly.

767 with United Airlines paint scheme:

A piece of fuselage wreckage at the WTC, with windows:

According to Eric Hufschmid, it is virtually impossible that this scrap on building 5 came from the plane that hit the North Tower because it would require the scrap make more than a 90 degree turn at 400 mph, so this confirms that the plane that hit the South Tower had windows.

I should take a moment to note that some researchers have found other non-visual forms of evidence which might suggest that a plane "substitution" could have taken place in the 9/11 plot, such as Discrepancies in official flight records, anomalies in the FAA and military response to the alleged hijackings, suspicious military war games occurring on the same morning, and so forth. I am not implying any opposition to these areas of inquiry; in fact, I believe they are quite worthy areas for continued investigation (and, for the record, the fact that I have been mentioning "flight 175" does not imply that I have ruled out these substitution possibilities). For now, I am just analyzing the visual record to determine what it can or cannot tell us reliably.


As it stands, the presence of a pod cannot be absolutely proven or disproven given the low quality of the visual record. The only evidence presented so far for it's existence is that in several low quality images it looks like there is a pod there. The pod advocates, who overwhelmingly bear the burden of proof, have not systematically proven that it could not have been an optical illusion. There is more than sufficient reason to conclude that the alleged pod is most likely the result of the play of light on the body of the 767 around its normal wing fairing, especially because this hypothesis holds up the best with the better quality images: the CNN footage, the Taylor photo and the new black and white photo of the underside of flight 175. So the question is, even if one still graciously allows for the remote theoretical possbility of a "pod" given the limitations of the visual record, should this be something that the 9/11 community embraces and presents to the public? Absolutely not, in my opinion, given the evidence we've seen so far. I'm not ideologically opposed to radical arguments like this, but if they're to be promoted they should be proven beyond the shadow of a doubt. The pod advocates haven't come anywhere close to that.

Beyond the physical evidence, there is much about the pod theory which seems illogical. Was it really necessary to augment the impact of the plane with weaponry? The thin outer walls of the WTC would not have created any serious resistance that needed to be overcome. And if the WTC was demolished with explosives, as many believe, there was no need to maximize the internal damage caused by the impact. If more damage needed to be done to the building or the plane, why not put powerful explosives safely inside the plane that would be totally hidden and not prone to any mechanical failures that can befall missiles or any hatches that needed to open on a pod? If there happened to be a better quality image of the impact, which theoretically could easily have happened, a pod or a missile fired from that pod could have been clearly visible, exposing the fraudulent nature of the attacks. Would the perpetrators have risked this? Even if weaponry was needed, and if it was a missile launcher, putting it at the juncture of the wing and fuselage would be a bizarre choice from an engineering perspective. The retracted landing gear would be sitting pretty much in the middle of the pod, which doesn't seem to me to leave much room for a missile!

At this point we have neither definitive proof of the pod's existence nor any logical reason for the perpetrators to resort to its use. The way I see it, the only responsible thing to do is to put the pod issue on the back burner until there is a more compelling argument presented. Otherwise, it will only serve as a distraction from other evidence for a 9/11 "inside job" that is genuinely credible and substantive, and worthy to be presented to the public.

More skeptical analysis on the pod can be found here, in an article by Mark Hungerford. He has very similar conclusions about the pod, although I'm not in complete agreement with all of his technical analyses. What he has to report about how skeptics are treated at the Letsroll911 forums is disturbing.