Discussion: Vector And Turn Analysis Of Observed And Measured Flight Paths Of 9/11 WTC Aircraft


Video footage depicts United Airlines Flight 175 (UA 175) impacting World Trade Center tower 2 (WTC 2) on September 11, 2001 in New York City via a trajectory comprised of two separate banked turns. The second turn was apparently not required to generate impact. The first turn, which maintains a constant angle of bank (AoB), is evident at 1.2 miles before impact.[1] Although human control of UA 175’s observed maneuvers cannot be ruled out, the precise coordination of variables such as the selections of a correct bank angle and turn start time for the first turn apparently pose challenges to the unaided human control hypothesis. The observed turn stability favors the use of autopilot operation, either functioning in a conventional course control mode or in Control Wheel Steering (CWS) mode. The probability that either of these two control systems were used is discussed. Flight deck images of United and American airlines 757s and 767s suggest that such CWS functions may have been disabled circa 2001. Constant radius turns utilizing plotted waypoints during commercial aviation operations are routinely supported by augmented GPS navigation service and related commercial Flight Management Systems (FMS) available circa 2001.[2] As will be demonstrated, the implementation of UA 175’s observed 1.2 mile constant radius arc, seconds earlier or later than observed, would apparently result in UA 175 missing WTC 2. Estimates of the likely effect of crosswinds on the approach to WTC 2 are also provided. It is noted that a projected impact via the first observed banked turn would have occurred under crosswind conditions capable of generating between 122 and 134 approximate total feet of lateral displacement from the calculated final position of the aircraft if not affected by such crosswinds. Aircraft distances and other calculations are based on reported aircraft speed for UA 175 of 799 feet per second at impact and measured times to impact [3]. The observed speeds of both attack aircraft were extreme by comparison to the typical speeds of similarly descending aircraft. While creating significantly less response time for possible human hijacker pilot course corrections during final target approaches that would demand superior control surface operation, a general vector analysis considering the final course and speed for each aircraft suggests that the unusually high speeds observed would generate greater accuracy of the aircraft while enroute to their targets, as a result of smaller course deflection angles and ground track displacements, created by existing and potential crosswinds.

Monaghan_Analysis_page numbered

Well Done Aidan

Lot's here for those with some technical expertise.
Your main point (I guess) is that the initial turn of 175 was a near perfect radius towards the center of WTC 2, needing just a minor angle adjustment a couple of seconds before impact.

What are the chances an in experienced hijacker-pilot could choose such an accurate turn radius? The accuracy of the turns that a GPS guided remote control system would have has more chance of this kind of accuracy.

As a layman I found some of the sentences overly long and cumbersome, having to re-read them. Maybe it's just me.

Great work.

Additionally, air pressure is a function of velocity squared

Aidan, nice write up.

To add to what you say here, the fact that the airspeeds of the WTC 1 and WTC 2 aircraft were 2.5 times and 3 times normal runway landing speeds means the air pressures on control surfaces and the airframe would have been 625% and 900% greater than that experienced while landing a wide bodied aircraft. This much greater pressure would have greatly exacerbated any errors a pilot would have made.

Not the same airfoils...

I suggest that one do more research about airliner, or complex adjustable airfoils and the resulting airpressures above, below, in front and behind the various parts of aircraft during various portions of flight and configurations of the aircraft's wings. This part of the consideration...ie: pressures that are 625% and 900% more than at approach and landing speeds, is unintentionally misinforming.

Its very important to note that at landing speeds the airfoil designs on large aircraft wings are RADICALLY different [called a "dirty" wing] than when the same aircraft is at high speed flight...[at high or low altitudes] and its [called a clean wing].

This is accomplished by the extention or retraction of both wing leading edge devices often called "slots" or "leading edge devices", and what is known as "wing flaps" which are extended along the rear edge of the wings. The use of such adjustable "flap" settings are ALL utilized at lower speeds of flight and are never used at top speeds of flight.

In fact, there are maximum airspeed limitations of what is generally called "degrees of flap settings" and the general rule is that the slower the aircraft needs to fly, such as the during take-off which is an acceleration process, but more importantly, during approach and landing which is a slower and slowing process, the greater "the degrees of flaps" are required.

AA11 and UA175 were "clean"...meaning their wings had NO flap extentions and thusly, were set up for maximum "clean" flight speeds which can be MUCH greater than normal "operating" speeds found in the aircrafts flight manuals. Therefore, to compare air pressures during this "clean" wing profile for high speed flight versus the air pressures during the "dirty" or flap extended wing profile is frankly, impossible.

The long fuselages are designed to move through the air as easily as is possible and the force changes on this non-changeable set of surfaces is minimal. And the "clean" wing profile and other airfoils at the rear of the aircraft [the verticle stabilaizer and rudder, and the horizontal stabilizer and the elevators] are also designed to move throught the air as effortlessly as is possible. Most of the resistance, or "drag" affecting an aircraft is caused by the "lift" generated by the airflowing over the wings. This airflow creates the "lift" needed to support the aircraft in flight and the work that the air does going over the wing produces the "drag" that prevents the aircraft from accelerating to even higher speeds. There is some resistance generated by all the leading edge surfaces of the wings, tail airfoils, the nose and other proturbances along the fuselage that hit the air passing by head-on. [such as the landing gear "pods not bombs" seen on UA175]

Another way to explain this is to state that "fatter" wings move through the air slower due to that "fatness"...BUT, such fatter wings produce more lift and do not need to fly through the air as fast as a "thinner" or high speed wing that we see on airliners when we are flying up at altitude. Upon approach and landing, the pilots sequentially make the wings "fatter" or more lift producing so that as they slow the airliner for landing, the "fatter" or higher lift wing can create the same amount of lift at these slower approach and landing speeds as does the thinner "clean" wing at the required higher speeds.

So, the 625% and 900% increase in forces on the airfoils as expressed here [not the tube-like airfoil] are NOT real beacuse the in-flight [clean] versus the landing [dirty] wing configurations are COMPLTELY different airfoils creating completely different lift and drag components.

Now, IF the wing flaps were extended at the high speeds noted for AA11 and UA175, now THAT indeed would tear the aircraft completely apart. THIS is why there are upper airspeed limitations for the use of ANY flap settings. A pilot simply cannot make the radical changes to the wing airfoils when at higher speeds...he or she must first slow the aircraft down to each successive flap speed limitation before extending the flaps any further.

Again, we can see this happening as airliners approach the airport. Its a "clean" wing at cruising altitude about 100 miles out and during the majority of the descent from high cruising altitudes. Then, as the aircraft gets lower and closer to the airport, air traffic control must mix all the arrivals into a landing sequence in such a way as to allow each succeeding airliner enough room behind the preceeeding airliner to allow the succeeding airliner enough room to slow down to the same landing speed as the preceeding airliner attains at touchdown. This is accomplished by the issuance of assigned airpeeds to be flown behind the preceeding airliners...and to accomplish this sequential slowing of the arrival que, pilots keep increasing the "degrees of flap extention" so that the airliner's wings will create the needed "lift" at the next assigned slower speed.

Eventually the flap settings for landing may reach about "40 degrees flap" and is often accomplished in four steps of ten degrees each. [please note that each airliner type is unique and I am generalizing here.] The lower and slower, the higher degrees of flap settings are eventually reached. Its quite the opposite on take-off as only 10-20 degrees of flap are required because the airliner is constantly accelerating. Soon after take-off, and during the climb out, these smaller flap settings are shortly eliminated as the airliner gains speed in the climb-out. Eventually, the wing has "zero degrees of flap" [clean] because the airliner is really moving fast enough for the "clean" wing to generate the lift without any flaps being extended at all.

So, after all that, comparing air pressures on an airliner as a function of a "high speed cruise" or "clean" configuration VERSUS a low speed or "dirty" wing configuration is comparing apples and oranges...and it simply cannot be done with any accuracy.

Therefore, the 625% and 900% figures noted in this post are totally irrelevant and very, very misleading because its NOT the same wing when flying at the higher speeds versus the wing flying at lower landing speeds because each realm of flight are utilizing the different wing configurations established for each of those realms of flight.

Regarding all the other stuff, as usual, Aidan does such amazing and illuminating work. Thanks Aidan.

9/11 Truth for World Peace and Justice

love, peace and progress...

Robin Hordon
Kingston, WA

Why don't we say for the same configuration


The reality is that air pressure is a function of velocity squared.

It is a different argument that the wing configuration during landing, with flaps and slats deployed, generates more pressure on the underside of the airfoil.

I am really talking about control surfaces like the rudder, elevators, and ailerons or spoilers, which are not affected by the landing configurations of the wings.

To make the argument clear I'll say that the air pressure on the aircraft would have been significantly greater than it would be at normal low altitude speeds, prior to deploying flaps and slats.

With higher pressure the same control surface movement as that used at lower speeds and pressures has a larger force generated on it, which is not compensated for elsewhere, and will result in a larger change in aircraft attitude. In other words, the same rudder movement at 400 knots will produce a significantly greater turn about the yaw axis than it would at 200 knots. The amount of control surface movement required at higher airspeeds, for a given attitude change, is much less than it is at lower airspeeds and thus the accuracy needs to be greater. This is why it would have been hard for a human pilot to control the aircraft to the degree needed, and to hit relatively narrow targets while moving at the airspeeds they were.

The gist of the argument here is that any slight errors by a human pilot would have been amplified by the significantly higher pressure.


...that human based control inputs at such high speeds would not be reliable means of generating such amazing accuracies required to hit the WTCs.

There is absolutely no doubts in my mind that the navigation and control of AA11 and UA175 were managed through the aircraft's sophisticated navigation and flight management-autopilot [old words] systems.

Way back then I was in on the inauguration of INS and RNAV and other attempts at upgrading the flight efficiencies of turbojet aircraft. There were sophisticated plans and concepts both on the table and in use back in 1981...and as Aidan has so incredibly informed us, most of these upgrades were available before 9/11/2001.

Basically...plug the coordinates or way points of the sides of the WTCs into the NAV systems...turn on the filght director/autopilot...and its a go!

My responses are to inform the average Truther, or citizen about some very complex interactions of flight.

Its all pretty damned complex and I felt that the 625% and 900% equasions were easily misunderstood...so now some folks have had a solid primer about some "aviation stuff".

9/11 Truth for World Peace and Justice

Robin Hordon
Kingston, WA

Good Stuff Indeed

To a layperson such as myself (with respect to aircraft), the idea of flying a plane into the towers seemed so simple. Just steer into it. Yet I've heard that tons of pilots recognized the difficulty immediately, and these calculations explain why.

On the other hand, the trajectory into the Pentagon never made sense to me. When I heard the Pentagon had been hit, I naturally assumed (for such a small vertical target profile) the plane must have crashed on a downward vector into the building ... whereas it hit the building on a near straight horizontal vector. I found that to be just an extraordinary maneuver. And then later upon learning of the lack of expertise of the pilot .... as well the dramatic vertical descent prior to horizontal leveling ... It's just impossible.

The treasure trove of evidence rendering the Official Story ridiculous is just mind boggling large. So large, in fact, it almost works in favor of the Story ... that is under the old adage ... the Bigger the Lie - the more certain it will be accepted.

This is why it's simply not necessary -- when you are trying to get your foot in the door -- to even mention government involvement. For so many people - that's so hard to accept. It's much easier to say Government cover-up for something that's so impossible.

Now Government cover-ups are much, much more common easier for people to swallow. Anyone who will look at this with a semi-open mind will reach their own conclusions regarding government involvement. If you want the horse to drink, you need to first lead it to the water. You have a much better chance of getting the horse to drink if you lead it by accusation of cover-up instead of complicity.

Precise Bank Angle Started At Precisely The Correct Time

Unlike all other footage of UA 175, the video and still frames above show that UA 175 began its critical maneuver over one mile from its target. Traveling at 799 f/s means that starting this approximately 20 degree banked turn seconds too soon or too late would apparently result in a miss without significant correction or a greater or lesser bank angle. Other than wild luck, only GPS guided autopilot control could generate this level of accuracy.

The unusually high aircraft speeds (a drift deterent) only make sense if the planes knew precisely where they were going. GPS timing and the ability of the Pegasus FMC to calculate enroute wind affects, supports this capability.

Which Flight 93?

Which Flight 93? There were two. Primary 93 and Fallback 93.

ACARS has Flight 93 wheels-off at 8:23. Unfortunately, the official Flight 93 didn't even leave the terminal until 8:42.

The Fallback Flight 93 landed at Cleveland Airport around 8:50 am.

Dean Jackson/Editor-in-Chief DNotice.org
Washington, DC

I did not realize the amount of exact precision.

Aidan, thanks for pointing this all out.
"...UA 175 began its critical maneuver over one mile from its target. ...this approximately 20 degree banked turn seconds too soon or too late would apparently result in a miss.... "
...and then...
"At approximately 2.5 seconds prior to its impact... ...UA 175 banks an additional 18 degrees to its left," (so it would be "21 feet closer to the center of the south face of WTC 2.")

"UA 175's final 18 degrees of final banking turn to its left, which would generate an estimated lateral movement of approximately 21 feet closer to the center of the south face of WTC 2 than the groundtrack created by its next-to-final turn, may suggest an autoflight system under augmented GPS guidance attempting to correct a trajectory for interception of a geographic waypoint located at the center of WTC 2."

VELOCITY - It wasn't until recently, that I realized the necessity for such abnormal high speeds for Flight 175 and Flight 11. The Towers were built like a huge metal mesh reinforced cheese-grater inside to the outer. I had to compare it to the analogy of a marble. Shoot a marble against the wall with a thumb and it bounces off. Throw a marble against the wall and it might dent the wallboard. Put an marble in a shotgun and shoot the wall. It will penetrate. If those planes did not have an extremely high velocity, they may not had effectively penetrated the Towers. Example: The recent Austin IRS plane crash into a building shows part of the plane outside the building (i.e. mass and velocity were low).

Excellent research Aidan.

Although I don't have all the skills needed to absolutely verify the information you present here I do understand your point clearly. It strongly supports the idea of computer control of the aircraft as opposed to human control. I wonder if you have seen the video showing a light anomoly tracking across the tower face that was struck just prior to impact?

Here is one video that captured it:

Here is another:

Let me know what you think. These videos have disturbed me for a while now.

There is a longer full length version of that which reveals..

That it IS in fact a piece of floating debris, or more than one piece of debris, where you can see the same type of stuff floating all around at the appropriate distance between the camera and the foreground building. I thought, was CONVINCED, for the longest time that it was a targeting laser light spot, but someone showed me the longer video, with all the pieces of paper floating around and I had to abandon the theory - as such, we ought not be pushing this any more. It's been fully proven, debunked whatever you want to call it.

However, detailed proportional length analysis of the south tower plane reveals that it was not and could not have been the original flight 175 a Boeing 767-222, but is instead the 300 version, which is slightly longer both for and aft of the wing section.

Interesting Robert thanks for the info.

I did not know this had been debunked but I am interested in looking at the video you described. Please understand I am by no means pushing this as a theory I am just interested in it as being worthy of discussion. I do not think it is floating debris though because it is too bright, it appears prior to impact, moves too fast to be wind driven, it tracks in a straight line, and its course isn't affected by the explosion. It looks like a beam of light to me the way it changes across the uneven face of the buildings. I could buy that it is video trickery but calling it debris does not seem to add up to me. I certainly respect your opinion though Robert and am completely open to evidence that debunks this and I grant you that I may not have taken all the variables into account. Please let me know if you locate the video I would like to see it.

Aidan, again, you rock fact and data

Your FOIA request's will be legendary after the perps are in jail.

This new equally fine presentation of the precision required of the 'pilots' to hit the towers is also a high mark that should be a beacon for us all to match when trying to expose the truth about 9/11.

How many people reading have driven a car, better a motorcycle, at high speeds, above most highway limits, even if only by 10 or 20 mph, and experienced a non-linear, dramatic difference in ability to keep the vehicle on a desired course? This is because of the aerodynamic pressure which becomes more pronounced at higher velocity. You can feel the effects even when riding a bicyle.

It is critical to understanding, and for the 'official story to explain, how inexperienced pilots, under the extreme duress of committing the most heinous crime (or if you were to believe the official story, the most ecstatic act), managed to pilot two jets into two, in the relative scale of the capability of a jet to hit, tiny targets that were the WTC towers.

There is such terrible irony that even while people watch Myth Busters and learn that such things are not so easy to accomplish, the official story continues without 'official' challenge.

Hello Myth Busters, can you take on 9/11? Aidan 's already written the script and episode plan ....