Part One - Plane as Missile (ie: remotely piloted drone aircraft)
 
Speed of Plane (575MPH) Long Approach (left side)
http://www.vialls.com/wtc/radiocontrol.html 
 
Maneuvering
CNN 2nd plane strike (right side long approach)
http://www.cnn.com/video/us/2001/09/11/exclusive.crash.cnn.med.html
CNN 2nd plane strike 
http://www.newsfocus.org/video/2nd.plane.hits.cnn.med.asx 
 
Evidence of high G-force final turn (upward bending right wing during final high G turn to WTC target)
http://www.amics21.com/911/imags/ua155_g.jpg
http://img357.imageshack.us/img357/7106/impact3a7hh.jpg
http://www.september11news.com/YahooTopPicsEmail2.jpg
 
Low probability of amateur pilots driving planes
Russ Wittenberg Interview
Airline Pilot Challenges Official 9/11 Story (text)
http://letsroll911.org/ipw-web/bulletin/bb/viewtopic.php?t=4565
Audio Interview
http://911underground.com/WING_TV_2004-09-16_Russ_Wittenberg_Interview.MP3
The Impossibility of Flying Heavy Aircraft without Training, Nila Sagadevan 
http://www.scholarsfor911truth.org/Sagadevan21Feb2006.html
 
Proof, the South Tower Plane was NOT and could not have been the original flight 175
http://letsroll911.org/ipw-web/bulletin/bb/viewtopic.php?p=105783#105783 
 
Presupposition and Conclusion: 
Since the south tower plane has be shown not to have been the original flight 175 (part two of this analysis goes on to confirm this conclusion well beyond any reasonable doubt whatsoever), and, if it may be assumed that a US Air Force pilot was not at the helm for a kamakazi mission, then the logical, deductively reasoned conclusion which must be drawn, is that this aircraft was in fact, a remotely piloted drone aircraft, the technology for which was certainly in place by 9/11 - see opening segment of 9/11 documentary "Loose Change, 2nd Edition" for more information about remote technology. 
http://video.google.com/videoplay?docid=-5137581991288263801&q=loose+change 
 
Part Two - Military Boeing variant "plane-as-missile" seen firing missile pre and during impact. 
Visual evidence of "pod", shrouded missile firing canopy ("pipe-barrel") and actual missile launch pre impact. 
 
3 dimensional "pipe-barrel" structure (contextual framework)
http://letsroll911.org/images/fueljetspray.jpg
Open link and resize for a split screen comparison, relative to the flame-flash/missile apparent in the following two video clips
1) http://www.letsroll911.net/images/CourtesyCNNABC.wmv 
2) http://www.letsroll911.net/images/Pip%20Low.wmv 
Note the point of flame-flash emission wich is well back from the nose and well right of the front fuselage, corresponding with the end point of the "pipe-barrel" structure. 
http://i.cnn.net/cnn/SPECIALS/2001/trade.center/gallery/unimaginable/2.jpg
http://www.letsroll911.net/images/1d.gif
Pipe Structure highlighted
http://www.amics21.com/911/imags/bumps.jpg
http://www.amics21.com/911/imags/tanks.jpg
Additional Info on 3D Objects (digital photographic analysis)
http://www.amics21.com/911/flight175/third.html
http://www.amics21.com/911/flight175/conclusions.html
 
"Pod" framework
same phenomenon, seven point comparative framework 
http://www.questionsquestions.net/WTC/podimages/2ndTowersmall.jpg 
It the 'bulge' (pod) a wing root fairing? 
http://www.september11news.com/YahooTopPicsEmail2.jpg 
Flame-flash impact photo (yet another camera and position) 
http://i.cnn.net/cnn/SPECIALS/2001/trade.center/gallery/unimaginable/2.jpg 
Evan Fairbanks ABC Video frame (yet another camera and angle) 
http://www.letsroll911.net/images/fuss.gif 
CNN/ABC video slomo (present through all the frames) 
http://www.letsroll911.net/images/CourtesyCNNABC.wmv 
Clark Photo 
http://img357.imageshack.us/img357/7106/impact3a7hh.jpg 
1st two frames. Ignore arrowed comment. 
http://www.questionsquestions.net/WTC/podimages/cnnpodsequence.jpg 
 
Conclusion re: flame-flash/missile
In the right side-on view Camera Planet slomotion video frames, it is apparent that a white object emerges from the same point as the end of the pipe structure, and then flames upon "fusing" with the building, the reddish-orange flame of which is the only thing seen in the rear angled CNN video. 
http://www.letsroll911.net/images/1d.gif
http://www.letsroll911.net/images/1f.gif
http://i.cnn.net/cnn/SPECIALS/2001/trade.center/gallery/unimaginable/2.jpg
 
Now, while these three dimensional structures, and the occurance of the flame-flash, combined with the wing to body length proportion analysis, most certainly prove, both individually and collectively, that the south tower plane was not and could not have been the original flight 175 (and therefore a remotely piloted drone aircraft) - it is my contention that it can also be determined, by an extension of rational, deductive reasoning, through the entire comparative, contextual, analytical framework, combining all observed phenomenon and information according to Occam's Razor - just what we are seeing, and what the true nature and identity, and purpose of this plane really was. 
 
First of all, it is apparent in no uncertain terms, that the plane's proportional length is too long for flight 175, that the 3D structures (pod and pipe) are in fact real, and that the end of this pipe emits a flame-flash, and in the case of the right side Camera Planet segment, a white object which then becomes the equivalent of the reddish-orange flame seen in the CNN video, when that object fuzes with the outer wall of the south tower. These are facts, not speculation, and while there have been strenuous attempts to debunk the validity of the pod observation as nothing more than the wing root fairing reflecting sunlight (refuted IMO by the multiple comparative framework offered above), Boeing officials themselves, when formally questioned about it, simply stated, after several days of photographic analysis "we are not able to tell you what it is, for security reasons"
http://www.amics21.com/911/flight175/conclusions.html

Furthermore, there has yet to be offered any suitable debunk of the flame-flash emisssion, the only explanations offered being either a "nose cone radar assembly impact explosion", which is refuted by the positioning and the Camera Planet video which reveals that the phenomenon occurs PRIOR to the nose/building impact, or, a "friction spark" leaping from the building to the plane (or vice versa), which the Camera Planet video also refutes, along with the comparative analytical observing framework offered above in this article and analysis. 
 
What has been proven therefore, is that it is something emitted from the plane, and more specifically from the end of the "pipe-barrel" like structure on the lower right hand side of the fuselage, and that from the right side Camera Planet video slomo perspective, it is a white object, which then flames reddish-orange when fuzing with the building. 
http://www.letsroll911.net/images/1f.gif
 
Therefore, in light of what has been already shown, and, in terms of what's to follow in this analysis, I content that what we are looking at here, recorded in real time, when it happened, and therefore making of this analysis, a type of physical, first hand, recorded in real time, eyewitness testimony evidence level presentation (much like a CCTV capture of a robbery in progress) - is in fact a pre-impact missile being fired, with extraordinarily high precision timing, and more specifically, a DU (depleted uranium) encased missile (glowing white) flaming at the fuzing point with the building exterior, and most certainly packaged with a FAE (fuel air explosive) military warhead, a probable candidate for which would be a "thermobaric warhead" which is one of the most advanced FAE bombs/warheads in the US military arsenal. The byproduct of an FAE warhead detonation, is internal destruction, and explosive ejection of building material, but mostly it occurs in the form of a large fireball detonation. 

More on missiles and on thermobaric hyperbaric warheads 
http://letsroll911.org/ipw-web/bulletin/bb/viewtopic.php?t=3899 
 

Let's examine the fireball magnitude. 
 
Fireball
http://serendipity.li/wot/i17787-2001sep12.jpg
http://serendipity.li/wot/crash.jpg
German Engineers' Fireball and Kerosene Smokecloud Analysis
Note that they came to the conclusion that a 767-200 fully fueled for a cross-continental trip to LA could have contained a sufficient amount of fuel to account for the fireball and smoke cloud observed - without knowledge of the Tanker Transport Military Boeing 767 Fuel Cargo Plane or of of the extra equipment [pod and pipe structure] retrofitted to it. 
http://home.debitel.net/user/andreas.bunkahle/jpg/Plate34.JPG 
http://home.debitel.net/user/andreas.bunkahle/jpg/Plate33.JPG
 
In this case
http://serendipity.li/wot/i17787-2001sep12.jpg
Note the explosive cement debris being ejected from various sides of the building. 
 
There is also a segment in Loose Change 2nd Edition which shows an explosive ejection close but away from the plane explosion exit area, which give evidence of additional simultaneous charges being detonated at around the moment of impact near the impact area. Both of these things, FAE warhead detonation, and planted explosives within the building being detonated at about the moment of impact, would have served to punch out the holes from which the volume of fireball was ejected and to scale up the fireball for the desired "shock and awe" pyrotechnic theatrical "psy-op" effect, so as to create, in the minds eye of the horrified watching world, a suspension of disbelief as to the cause of the near free fall total destruction of the twin towers (fire). Much like a "slight of hand" magic trick. 
 
No video fakery however, was required, and that hypothesis simply does not hold water given the sheer number of eyewitnesses and photographic and videographic sources which have been available since day one. 
 
The best possible explanation, in terms of the entire occurance of the event itself (plane on approach through impact and fireball) when taking into consideration ALL available observable phenomenon and all information, including that available on the War Games Operations under way on 9/11, headed by Dick Cheney, involving LIVE FLY simulated hijacked aircraft being flown as missiles into landmark buildings, including the WTC ON September 11th, 2001 - is the military drone hypothesis (more info to follow). 
Note: If there are wistleblowers to be had, we need them to come out about these War Games which in effect served to STAND DOWN any effective military response on 9/11 which might have prevented the strikes. 
 
As far as the issues raised by Morgan Reynolds regarding building penetration AND deceleration, I believe that the Tanker Drone hypothesis, travelling at a high rate of speed (550-575MPH) [INERTIA], hardened somewhat (see Tanker info below), firing in a DU encased FAE warhead just a fraction of a second before impact, detonating just slightly ahead of the mangling plane, is sufficient to explain the actual occurance of the event itself. 
 
Conclusion: 
 
A Military Boeing 767-300 (as opposed to a 200 or a 222 to be precise - Flight 175 N612UA) Tanker Transport Refueling Cargo Plane, futher re-engineered with remote piloting avionics, as well as, a shrouded pod and pipe-like missile firing canopy (to try to hide last moment missile ignition launch sequence from view), firing a DU encased missile with FAE warhead a splt second before entry, as actually observed "in plain sight" - is almost certainly the culprit, and without any doubt whatsoever (PROVEN by observation), it most certainly was NOT the original flight 175, N612UA. 
 
Description
 
KC-767 TANKER TRANSPORT AIRCRAFT, USA
The Boeing 767 tanker transport aircraft, designated KC-767 for the US Air Force, is a high performance version of the Boeing 767-200ER twin aisle jetliner equipped for fully integrated tanker operations. It is fitted with either boom and receptacle refuelling, hose and drogue refuelling or both. The commercial 767 first entered service in 1982 and more than 880 aircraft have been delivered. The cabin of the tanker can be configured for passenger transport, as a freighter, convertible (passenger or freighter) or Combi (passenger and freighter). 
 
Design: (hardened shell)
The structure incorporates new materials such as improved aluminium alloys, graphite composites and hybrid Kevlar graphite composites, which give enhanced strength, durability and longevity.
http://www.airforce-technology.com/projects/kc767/
 
KC-767 Common Widebody Tanker & Transport
The Boeing 767 family of aircraft, specifically the –200C/F, 300C/F and –400C/F models, have been proposed by Boeing as a replacement for the KC-135 family of aircraft, and have been vigorously marketed by Boeing. In terms of offload performance, the proposed Boeing KC-767 modestly outperforms the standard KC-135R. Costs for used 767-300ER aircraft vary between $51M and $88M, depending on the age and condition of the aircraft. In terms of speed its Mach 0.8 performance compares to the Mach 0.85 or better performance of the KC-135 aircraft. 
 
The KC-767 will be the world's newest and most advanced tanker. It can offload 20 percent more gas than the KC-135E and unlike the E-model, can itself be refueled in flight. It will also have the capability to refuel Air Force, Navy, Marine and allied aircraft on every mission. At maximum takeoff weight, the KC-767A requires 4,000 feet less runway than the KC-135E. Besides its role as a tanker, the KC-767A will be configured as a convertible freighter and can carry 200 passengers or 19 pallets of cargo 
http://www.globalsecurity.org/military/systems/aircraft/kc-767.htm 
 
Image
http://www.airforce-technology.com/projects/kc767/images/767tanker_1.jpg
 
Two more observations:
 
No Passenger Windows? 
http://www.911inplanesite.com/911trailer.html 
(Scroll to No Windows on Flight 175)
Image # 6588 @ http://hereisnewyork.org/gallery/thumb.asp?CategoryID=-1&picnum=4093 
(Install Viewpoint - quick and easy - to Magnify X10) 
 
Dark Circle under Tail (Refueling Boom Removed?) 
Note that there is no such mark, tail skid, or avionics blade antenna at that location for a normal Boeing 767-200, and therefore nothing else to account for this perfectly circular blemish visible in both the still photo and the CNN freeze frame. 
http://www.letsroll911.net/images/unders.jpg 
http://i.cnn.net/cnn/SPECIALS/2001/trade.center/gallery/unimaginable/2.jpg 
 
Compares may be found here 
http://www.airliners.net 
Click "Take Me To The Photo Search Page!" 
Then click the following: 
Aircraft Type... Boeing 767 - don't click 200, just 767 here 
Airline...United Airlines 
Country / Airport...Leave this one 
Category...Passenger Aircraft 
Keywords... Type in 222 
And in the Diplay Options, click Photo's only (more per page) 
And in Limit Options, click 60/page 
 
Actual Flight 175 
Medium 
http://www.airliners.net/open.file/205074/M/ 
Large 
http://www.airliners.net/open.file/205074/L/ 
United Airlines 
Boeing 767-222 
New York - John F. Kennedy International (Idlewild) (JFK / KJFK) 
USA - New York, April 28, 2001 
N612UA