NOVA Video - "A Very Perculiar Aeroplane"
This section is rather lengthy so let's start by stating that most of the
images here have been processed using Photoshop utilizing primarily the
Focus Magic plug-in for Photoshop. I've also used the standard functions
in Photoshop along with the Quantum Mechanic and the Neat Image plug-ins.
To begin with, relevant fields of the UA175 aircraft and WTC2 tower were
extracted from the NOVA DVD 'Why The Towers Fell'.
These extracted fields of the UA175 aircraft and WTC2 tower were composited
in Photoshop allowing us to see the entire airframe in relation to the WTC2 tower.
The image below shows the result of a basic enhancement using the 'fix motion blur'
function from the Focus Magic plug-in and the 'levels' function native to Photoshop.
The motion blur correction factor was gauged using the tail section and the
starboard wing collectively:

With the motion blur removed we can now see a much clearer and sharper airframe.
The elongated marking on the front of the fuselage that some people believe
to be a missile turns out to be a circular luminescent patch.
The motion blur makes the circular luminescent patch look longer
and darker than it actually was in the uncorrected image.
Please note that the dark patches adjacent to the circular
luminescent patch are a function of a limitation in the video technology called 'ringing'.
It is highly unlikely that these black markings are actually as real as they appear to be.
With a basic level of enhancement established we can resolve the NOVA UA175 impact
sequence in its entirety. In the contact sheet below motion blur was
removed across each individual image and the 'levels' were optimized
across the entire composite:

Comparative visual examination of the NOVA UA175 aircraft reveals a shorter
wing chord length and relative forward positioning of the wings.
The nose tip is more reminiscent of a torpedo than an aircraft
and the asymmetric tail section with its high sweep back angle
aerofoils look like they have more in common with the aerodynamic
stabilizers from an arrow or dart. There is the possibility that
the wings are shorter than the wings on the Boeing 767-200 although
this is speculative because it is difficult to accurately gauge the
bank angle of the NOVA UA175 aircraft.
A technical analysis reveals that the fuselage trunk
length of the NOVA UA175 aircraft is approximately 3.5
meters shorter than the 47.24 meter fuselage trunk length
of the Boeing 767-200. This puts the NOVA UA175 fuselage trunk
length at approximately 44 meters.
The diameter of the NOVA UA175 aircrafts fuselage is approximately 4 meters,
putting it just 1 meter short of the Boeing 767-200's fuselage width of 5.03 meters.

Further examination of the NOVA UA175 aircraft in comparison
to the CG Boeing 767-200 exposes a host of discrete airframe and
lighting anomalies.
I've numbered theses anomalies from 1 to 9 in the image below:

1 - Circular luminescent circular patch toward the nose of the UA175 aircraft.
2 - False wing shadow on fuselage.
3 - Excessive sweep back angle on tail fin.
4 - Small and thin starboard tail plane section.
5 - Apparent tail fin logo.
6 - Excessive sweep back angle on port tail plane.
7 - Apparent symmetrical flattening and bulging of rear fuselage underside.
8 - Possible excessive sweep back angle of port wing.
9 - Incorrect sun illumination on fuselage.
The circular luminescent patch (1) could be a specular reflection from the fuselage:

But as you can see from the montage above, the reflection should
be elongated rather than circular.
Flight Simulators 'dynamic reflectivity' function produced highlights
across the entire front section of the fuselage in a similar fashion as
exhibited by the 3 United Airlines Boeing 767-200's shown below:

The circular luminescent patch doesn't even appear on the tapered section of fuselage.
If you look closely it's on a straight section of fuselage so the reflection would
have to be elongated. The circular luminescent patch also occurs on a point
where the fuselage is in partial shadow (9) and consequently my conclusion
is that the circular luminescent patch is not a specular reflection at all.
It appears to be an independent source of light.
Please note that the shadowing on the fuselage suggests that the
sun was at a much higher position in the sky than it actually was at 9:03am in Manhattan on 911.
It is conceivable that the dark underside of the fuselage is actually the aircrafts livery.
If this is the case then the NOVA UA175 aircraft did not have a United Airlines livery.
Instead it has a bland, grey livery with no prominent
markings other than a possible logo on the tail fin (5).
For some reason the starboard wing of the NOVA UA175 aircraft
seems to be casting an impossible square shadow (2) on the fuselage:

From this viewing angle the shadow should be triangular in appearance,
starting at the rear of the wing root and making its way
back to the top of the fuselage and then terminating at a
point equidistant from the tail fin to the middle of the fuselage:

I could find no match for the sharp sweep back angle on tail fin (3)
in other Boeing and Airbus models.
This high sweep back angle is not a characteristic of
the Boeing 767-200 at the same viewing angle and attitude
of the aircraft seen in the video.
The starboard horizontal stabilizer (4) appears to be unusually thin
in comparison to the port horizontal stabilizer (6) and has a different
sweep back angle. The horizontal and vertical aerofoils at the rear
of the NOVA UA175 aircraft (3, 4 and 6) bear no resemblance to the
horizontal and vertical aerofoils of a Boeing 767-200.
The port horizontal stabilizer exhibits greater sweep back angle
than the port horizontal stabilizer on the Boeing 767-200 and the
port wing exhibits some sign of 'port wing anomaly' (8).
There is only one apparent similarity between the NOVA UA175 aircraft
and a real Boeing 767-200 with a United Airlines livery and that is
what appears to be a logo on the tail fin (5).
Technically this should be impossible because the CG Boeing 767-200
indicates that the starboard elevator is obscuring the tail fin logo.
On the rear underside of the fuselage of the NOVA UA 175 aircraft we
can see what seems to be symmetrical horizontal bloating and
flattening of the fuselage (7). This is not a characteristic
of the Boeing 767-200.

Having compared the composited NOVA UA175 aircraft to other Boeing and Airbus
models I can conclude that this aircraft does not match models from either manufacturer,
although the airframe bears a vague proportional resemblance to the Boeing
767-300 with its 53.67 meter fuselage trunk length.
The NOVA UA175 aircraft is not any Boeing 737,
the longest model being the Boeing 737-900 with an overall length of 42.11 meters.
In general the NOVA UA175 aircrafts asymmetric airframe is
shorter than a Boeing 767-200, appears to have a different
wing span to a Boeing 767-200, has a smaller fuselage diameter
than a Boeing 767-200 and has different aerofoil positions on
the fuselage to a Boeing 767-200. In other words the NOVA UA175
aircraft is not a Boeing 767-200 or any distinguishable aircraft
thus making it a very peculiar aeroplane indeed.
No analysis of the NOVA video would be complete without the 'flash' frame.
Due to difficulties enhancing the area around the flash I opted for nominal
visual enhancement:

It is not possible to determine where the flash emanates from,
but it does appear to be in close proximity to the circular
luminescent patch and inside the shadow wedge being cast by
the WTC2 tower over the aircrafts impact area.
It is conceivable that the circular luminescent
patch and the flash are related in some way.
The flash appears in other UA175 aircraft videos although most of these
videos seem to be fake and the shape of the flash in them is different
to the shape of the flash in the NOVA video. At the present time the
cause of the flash remains is open to speculation.
The set up of the NOVA camera shot is quite different from other UA175 impact videos.
The grey deformed UA175 aircraft only just makes it into frame and the video camera
angle suggests that WTC1 was the focus of the subject.
The recording of the UA175 aircraft in the NOVA video looks
genuinely fortuitous while showing no obvious signs of
forgery or manipulation:

If the NOVA video is fake then why did the forgers insert the wrong
aeroplane into the video, especially one that doesn't look like any
kind of aircraft at all. Other fake UA175 videos show a more convincing
aircraft than this, like the Park Foreman video as a good example.
Whatever the NOVA UA175 aircraft is, it is not the same aircraft
we see in the Live Video, the Robert Clark Photograph or the CNN Best Angle Video.
In fact, the NOVA UA175 aircraft is quite unique and stands out from
all the other supposed UA175 aircraft videos or photographs.