Although it's usually pretty obvious to most that it is impossible for a plane north of the gas station to hit the downed light poles, people sometimes have trouble understanding why this proves it could not have hit the building.
Hypothetically, there isn't a reason the plane couldn't hit the building from ANY approach -- but the point here is that, like the light poles, ALL physical damage including to the generator trailer and the building itself requires the plane to approach in a very straight, fast, low, level, and deliberate manner in a trajectory that is only in alignment with an approach south side of the gas station, the Navy Annex, and Columbia Pike at all times.
FAQ #2 on our website is the most comprehensive article explaining this in full detail with images so I will publish it here as well.
Why does it matter which side of the gas station the plane flew on? Couldn’t the plane have flown on the north side of the gas station and still hit the light poles and building?
As made clear in the video presentation National Security Alert, it is impossible for a plane on the north side -- let alone one in a significant right-hand bank as described by all witnesses who were in the best locations to observe the plane's flight path as it approached from over the Navy Annex -- to hit the light poles or cause the directional damage to the building as photographed and outlined in the ASCE Building Performance Report. This fact has not been contested by a single pilot, physicist, engineer, scholar, or skeptic who has viewed the information.
1. Light Poles
The downed light poles are in a straight line to the alleged impact spot. Only a plane flying in a straight line on a south side flight path can hit all five light poles. There is virtually no room for error. Even a minor deviation from this flight path would have caused the plane to miss one or more of the poles. A plane on the north side misses all five poles.
(click images to enlarge)
2. Damage to the building
The damage to the Pentagon, starting with the damage to the facade and leading up to the curious, almost- perfectly round hole in the C ring, is directional, meaning that it delineates a very specific trajectory for the plane.
This was noted as early as September 15, 2001 by Pentagon Renovation Manager Lee Evey, who said in a DoD News Briefing:
...this is the damage pattern that we see to the columns inside the building, and you can almost trace the path of the aircraft. This is why we believe it came in at an angle. The key here is, the red dots are where the columns are missing or cut completely.
That statement was made while he was showing a slide show containing this image (which is still available here on the DoD's website):
The specific trajectory required is the same straight south side flight required for the plane to hit the light poles.
The white image depicting the damage to the building leading up to the C ring hole, which has been scaled down to size and overlaid on top of the Pentagon in the image above, is taken directly from page 53 of the ASCE Building Performance Report. Here it is as it appears in that document:
Here are some pictures of the C-Ring hole, which is labeled "Hole in wall" by the ASCE in the image above.
The overhead image above showing the location of the internal hole in the C-ring (end of building damage) in relation to the outer damage to the facade (beginning of building damage) is photographic evidence that independently establishes the trajectory of the building damage as reported by the ASCE.
As you saw above, the south side flight path aligns with the damage path from the ASCE report image, and the fuselage lines up with the C-Ring hole. This is not the case with even the closest-possible hypothetical north side flight path, and remember, this path had the plane much closer to the station than all but one witness reported, and does not account for the significant bank reported. With these things taken into account the plane would have hit the building closer to perpendicular, causing a damage path that is even more blatantly inconsistent with observed damage path outlined in the ASCE report.
The images below are also from the ASCE Building Performance Report, and they all depict a south side flight path.
(Image from ASCE report, p. 19)
(Image from ASCE report, p. 36)
(Image from ASCE report, p. 39)
3. The generator trailer
Furthermore, the damage to the generator trailer outside of the building is also irreconcilable with the north side flight path described by the witnesses.
In the September 15, 2001 DoD News Briefing cited above, Pentagon Renovation Manager Lee Evey continued:
On its way in, the wing clipped. Our guess is an engine clipped a generator. We had an emergency temporary generator to provide life-safety emergency electrical power, should the power go off in the building. The wing actually clipped that generator, and portions of it broke off.
This allegation was also made by the ASCE.
On page 13 of their report they published this image, showing the plane approaching on a south side flight path and in line with the generator:
Then on page 18 they said:
The aircraft flew over the grassy area next to the Pentagon until its right wing struck a piece of construction equipment that was approximately 100 to 110 ft from the face of the building (0.10 second before impact) (figure 3.14)
Here is the image that they published on page 20 of their report as Figure 3.14 with the caption "Aircraft at impact with generator".
It's impossible for a plane approaching on the north side flight path described by the witnesses to have caused the damage to the generator trailer.
Statement from Robert Balsamo, an FAA certified pilot and certified flight instructor with 4000+ hours total flight time:
"A conventional fixed wing aircraft, 757 or otherwise, cannot maneuver from north of the former Citgo gas station to cause the physical damage to the light poles, generator trailer, or the Pentagon without structural failure of the airframe itself. The maneuver would require G forces exceeding aircraft capabilities and that of the human body. Physics and math do not lie. If you accept the placement of the plane as independently and unanimously reported by the witnesses presented in CIT's video National Security Alert, science proves that it did not cause the physical damage at the Pentagon on 9/11/2001."