Great New Video On Tv Fakery Options

[chek]

Hi dMole, sorry for the delay in responding.

[quote=dMole,Dec 22 2007, 10:30 PM]I take issue with several things in the Youtube video. Again, like the Mach 2+-designed F4 Phantom collision video, I find what I consider to be handwaving, "bait & switch" logical fallacies to make the video's case (or relevance to B757s/B767s).

A:= B757/B767 is a twin engine jet aircraft
B:= B-103 Blackburn Buccaneer is a twin engine jet aircraft
C:= B-103 Blackburn Buccaneer can fly at 667.58mph "at sea level" [Although it is obviously NOT AT "sea level" proper from the video- that gets splashy.][/quote]

Well let's go through your objections one at a time.
Btw, that video showed a flypast of the control tower taken as part of the Buccs stand down at its home base at RAF Lossiemouth on the shores of the Moray Firth in Scotland. The base's altitude is 19ft above sea level, well within our zone of interest.
http://www.rafweb.org/Stations/Stations-L.htm#Lossiemouth

[quote]D:= F4A Phantom II "Sageburner" can fly at 902.77mph at 125 feet AGL.

Given that A is true and B is true,
B == C (okay, granted, but is there another source besides Youtube with documentable B-103 low-altitude velocity? )
D == C (well, actually no, they are not even CLOSE to EQUIVALENT). [/quote]

There are numerous tales available of the Buccaneer's ability to outrun interception at low level - it was famous for it during its service life until it was withdrawn from service in the mid 1990's. Try the pprune website for example.

[quote]Therefore A == C == D (is this the "new math" I hear so much about??? ) Call me incredulous here, but I'm not buying EITHER of the assertions that A == C OR A == D! Since the alawson911 video opens with apples and oranges, I'm calling grapefruit, lemons, and cantaloupes at this point...[/quote]

The ability for aircraft to operate at low level without airframe 'disintegration' or engine ‘choking’, which is the point of the exercise is successfully demonstrated in the video.

[quote]I also saw a Colin Powell video in early 2003 showing how Saddam Hussein's mobile weapons trucks worked (which I somewhat believed back then because I remember Rumsfeld ACTUALLY selling WMD's to Saddam back in the Reagan Iran/Iraq War days). I saw Condi and Dubya talking about mushroom clouds... I also think we all can agree now that those Powell/Bush/Condi videos were ENTIRELY bullsh*t in retrospect..... [/quote]

Agreed. Most PR is. Beware presentations is a maxim to live by.

[quote]The text accompanying the "orange" video states:
"About This Video
Added: December 11, 2007
This video demonstrates that the speed of the aircraft which hit the South Tower of the World Trade Center, on 9/11, did not exceed the design limitations of its airframe or engines, and that the way in which the aircraft breached the wall of the building was feasible.
The video has been updated to correct a mistake in the kinetic energy formula, and to include previously unavailable clips of low-flying aircraft, rather than the supersonic jet car ThrustSSC."

(NOTE: This video actually states that "the design limitations of its [B767] airframe or engines" WERE EXCEEDED, if we can trust the 586mph figure. If you want to discuss the PHYSICAL limitations, that is another matter, but I don't see conclusive EMPIRICAL proof of 590mph Boeing airliners at 700 feet AGL here.)[/quote]

That is true as far as it goes – but it eloquently demolishes Joseph Keith’s assertion that the airframe would ‘shake itself apart’ before the documented max. gear down speed was attained, and that the engines would ‘choke' on the thicker air at low altitude’.
‘Thicker air’? The correct term a professional would use is ‘denser’, which may or may not be a further signifier of Keith's credibility.

[quote]Incidentally, my analysis of the USAF 84 RADES data shows an average velocity of 225-300 kts for the last portion of AA11. UA175 was averaging 425-450 kts at the end from my estimates based on USAF data. For reference, 500 kts ~= 575 mph.[/quote]

Yes, x1.15 is the mph to knots conversion formula. Even the RAE Farnborough (where they know a thing or two about aviation) ‘guesstimates’ were estimations based on the evidence available to them at the time. Given FFG’s previous supersonic interpretations of the radar records, I’ll pass on your interpretations and stick with the professional’s estimations until such time as harder evidence becomes available. No offence.

[quote]1. Rotational KINETIC energy of ANY relevant Boeing turbofan in the WTC gross overspeed conditions == ?? How do we know the engines will survive these angular speeds (FAR gives ONLY 105% of max. rated RPM for 2 MINUTES from my research)
2. Which (presumably transonic-designed) engine(s) are being referenced here?
3. [Per FAA Type Datasheet A1NM Rev. 26, p.1 of 12]:
"Airspeed Limits: VD = 420 KCAS to 17,854 ft/.91M above 23,000 ft, linear variation between these points.
VFC = 390 KCAS to 17,600 ft/382 KCAS at 23,000 ft/.87M above 26,000 ft, linear variation between these points.
VMO = 360 KCAS/.86M
VLE = 270 KCAS/.82M
VLO = 270 KCAS/.82M"
*** How long does one expect a "dive velocity" to last at 700-1000 feet AGL in a B757/B767 at V_d?*** [/quote]


Regardless of your research whose thoroughness we can only speculate on, apparently they did.
It should be noted that the purpose of the quoted limitations (in addition to passenger safety) are to enable quick turnaround to get commercial jets back in the air and earning asap. Exceeding handbook limits and popping strain gauges and/or rivets causing various possible categories of damage will result in hangar time and a displeased management. This wasn’t a major concern of the flight planners on that day.

[quote]3B. The "orange" video states arbitrarily: "FAA: 'Flight 175' = 586 mph" [= 509.22 kts]

509.22 kts / 420 kts = 1.212 V_d
509.22 kts / 390 kts = 1.306 V_fc [HINT: Vfc/Mfc = "maximum speed for stability characteristics"]
509.22 kts / 360 kts = 1.415 V_mo (V_mo = MAXIMUM Operating Velocity, but 0.86M is MAXIMUM operating mach "at high altitude" for B757/B77 = M_mo)[/quote]

Mach isn’t so much an absolute speed as a variable one depending on conditions – relating to when compressibility shockwaves begin to form - and depends on temperature and, particularly at low level, humidity.
At sea level at a temperature of 15C, Mach 1 is approx 760mph, but the curved surfaces around an airframe will induce local airflow to exceed the actual forward speed of the vehicle in some areas.
Mach 0.86 is 650mph at sea level but 560 mph at 30,000 ft.
http://en.wikipedia.org/wiki/Mach_number
500+mph is well below either figure.

[quote]4. 667.58mph = 580.11 kts for B-103 Buccaneer "at sea level [is that hydrodynamic then?]" )[/quote]

It's generally taken to mean when altitude is so low it has to be estimated by eye because the pressure altimeter is no longer functional.

[quote]From:http://www.blackburn-buccaneer.co.uk/Pages...es/0_Tech1.html?
"Design Speed (Max at 200 ft.) = 560knots (645mph)
Maximum Speed (Actual - 'clean') = 580knots (668mph) Mach 0.95"
580.11 kts / 560 kts = 1.036 V_design (at 200 ft.)
580.11 kts / 580 kts = 1.000 V_maximum
Vover_B767 / VoverB103 = 1.415 V_mo / 1.000 V_maximum = B767 at 141.5% of B-103 Bucaneer low-speed "overspeed" [/quote]

That’s low-level maritime strike for you. I think we can readily accept that in the tower flypast at Lossiemouth (the sea is just visible in the background) it wouldn’t have been armed or carrying anywhere near a full fuel load.
http://ourworld.compuserve.com/homepages/a...oks1/Xv361a.htm
"XV361 580 kts VERY VERY LOW LEVEL"

[quote]5. F4A Phantom II "Sageburner" 902.77mph at 125 feet AGL
http://www.nasm.si.edu/research/aero/aircr...el_F4A_sage.htm

"[likely another F4-H1] - 1961 November 22, world maximum speed record, 1606.505 mph, at Edwards AFB, LtCol. Robert B. Robinson USMC, pilot. "
902.77 mph / 1606.505 mph = 0.562 V_max [presumed HORIZONTAL flight from the video, NOT A DIVE]
Vover_B767 / V_F4 = 1.415 V_mo / 0.562 V_max = 2.518 TIMES the "relative" F4 Sageburner low-altitude velocity.
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"In late 1958, the F4H-1 was declared the winner of the competition and ordered into production. The original design was unstable at high Mach numbers and did not have acceptable low speed flying characteristics for carrier operations. McDonnell overcame the high Mach number problem by incorporating 23 degrees of anhedral for the horizontal tail and 12 degrees of dihedral in the outer wing panels, yielding greater stability at high mach numbers and installing variable geometry intakes to control airflow at high speeds. To address the low speed deficiency, the designers incorporated Boundary Layer Control (BLC) that used engine compressor air blown over the leading and trailing edge flaps.

There were two "Sageburners." The first one crashed from a combination of factors. The principal causes were the excessive sensitivity of the F4H-1 pitch control and pitch damping system and pilot error. Cdr. J. L. Felsman was killed when he caused a Pilot Induced Oscillation (PIO) which, /b]combined with high speed and extremely high aerodynamic pressure caused the airframe to distort to such a degree that it disintegrated. The engines, which had been at full power, broke loose and, maintaining the relative separation they had in the aircraft, continued down range for several miles, streaming smoke and fuel vapor before crashing.[/b]

Following this tragic accident BUWEPS conducted an extensive review of the probable causes. The chief culprit was the pitch control system, particularly the pitch control damping system. Accordingly, several changes, which simplified the system and made it less sensitive, were incorporated. The changes were evaluated in a PIO simulator owned by North American Aviation in Columbus, Ohio. Since aircraft companies are invariably highly reluctant to share knowledge with each other, transferring the F4H-1 flight control data from McDonnell to North American proved a daunting task but was done under supervision of the BUWEPS."
[Do commercial Boeing transports have Boundary Layer Control (BLC)???][/quote]

No, they don’t. They use other low-speed lift enhancing devices fitted (typically double slotted trailing edge flaps, leading edge slats and Krueger flaps. In either case it’s irrelevant to high speed flight.
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[quote]I also located the non-video source for you: "Lt. Hardisty and his Radar Intercept Officer (RIO), Lt. Earl H. DeEsch succeeded in flying "Sageburner" over the designated course twice at an altitude of 125 ft. to set a record that STILL STANDS of 902.769 mph." [Does anyone care to try to set the 125 ft. AGL speed record in an "off the shelf" commercial Boeing???] [/quote]

Why would they? Low-level high-speed passenger transportation is hardly an industry demand, whereas it’s quite a handy radar avoiding technique to the military.

[quote]HINT on UA175 overspeed conditions from:
http://www.boeing.com/commercial/aeromagaz...ly/fo01txt.html

"Aerodynamic principles applied to large, swept-wing commercial jet airplanes are similar among all manufacturers, and the recommended techniques for recovering from an upset in an airplane subject to these principles are also compatible. Pilots who understand the conditions of an upset, though such an event is unlikely, will be better prepared to recover from it. The four conditions that generally describe an airplane upset (figure 1) are unintentional:

* Pitch attitude more than 25 degrees nose up.
* Pitch attitude more than 10 degrees nose down.
* Bank angle more than 45 degrees.
* Flight within these parameters at airspeeds inappropriate for the conditions."

http://en.wikipedia.org/wiki/V_speeds

A little more on the [off-topic IMHO] B-103 Buccaneer:
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http://en.wikipedia.org/wiki/Blackburn_Buccaneer

"The Buccaneer was designed to fulfil Naval Staff Requirement NA39 (Ministry of Supply Specification M.148T) issued in 1953 for a carrier-borne strike aircraft with a long range (430 nautical mile radius of action), capable of 610 knots at sea level, carrying an internal load of up to 4,000 pounds (including nuclear weapons) - below enemy radar - and attacking ships or ports."

"The Buccaneer was a mid-winged, twin-engined monoplane with a crew of two seated in tandem under a sliding canopy. In order to meet the demands of the specification the Buccaneer featured a number of novel and advanced design features. The fuselage was area ruled; meaning it was designed to reduce drag at transonic speeds. This gives rise to the characteristic curvy "Coke bottle" shape.

The small wing of the Buccaneer is suited to high-speed flight at low level. Such a wing, however, does not generate the lift that is essential for low-speed carrier operations. Therefore, the wing and horizontal stabiliser are "blown" by bleeding compressor gas from the engine through surface vents. A consequence of the blown wing is that the engines are required to be run at high power for low-speed flight (in order to generate sufficient compressor gas for blowing). Blackburn's solution to this seemingly counter-productive situation was to provide a large air brake. The tail cone was formed from two leaves that could be hydraulically opened into the airstream to decelerate the aircraft."
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Does a COMMERCIAL B757 or B767 have ANY of these aerodynamics or engine characteristics?[/quote]

The designs differ according to their anticipated operating environments. The buffet induced fatigue life of a B767 at low level would be very short as that’s not what it’s designed for. Prolonging the aircraft’s service life was a hardly a factor to the 911 planners.

[quote]How does the B-103 Buccaneer jet intake area compare to a 90+ inch diameter large Boeing turbofan? Can someone provide me with the drag coefficients (C_d's) at various air densities for the sundry jet aircraft that everyone seems to want to add (extraneously IMHO) to these WTC/Boeing discussions?
http://www.grc.nasa.gov/WWW/K-12/airplane/drageq.html [/quote]

The Buccaneer employs 36 inch diameter Spey turbofans using exactly the same plain pitot type intakes as the B767. The difference in size is hardly an issue, as the intakes of each are optimised to cope with the mass flow of air through each engine.

[quote]"Drag depends on the density of the air, the square of the velocity, the air's viscosity and compressibility, the size and shape of the body, and the body's inclination to the flow. In general, the dependence on body shape, inclination, air viscosity, and compressibility is very complex.

One way to deal with complex dependencies is to characterize the dependence by a single variable. For drag, this variable is called the drag coefficient, designated "Cd." This allows us to collect all the effects, simple and complex, into a single equation. The drag equation states that drag D is equal to the drag coefficient Cd times the density r times half of the velocity V squared times the reference area A.

D = Cd * A * .5 * r * V^2" [NOTE: this equation as is NEGLECTS transonic wave drag- got C_d's?] [/quote]

The Buccaneer is optimised for fast low level flight for long periods as evidenced by its obviously area ruled shape which serves to reduce wave drag, in effect making the airframe more ‘slippery’ which contributes to its long range performance for a given amount of fuel.

Modern airliners are also extremely aerodynamically efficient, though not to the same degree as an aircraft designed specifically to operate in that environment and would require correspondingly more power (and therefore fuel) to maintain speed. As far as U175 is concerned, the low level run in was about a mile and a half after descent from altitude with (from memory) about 10K gallons to spare.

[quote]Please note that the Buccaneer S.1 was powered by 2 de Havilland Gyron Junior Mk101 TURBOJET engines. Does the Youtube video indicate which Buccaneer variant is depicted, or did I miss it? The S.2 variant used 2 Rolls-Royce Spey RB 168-1A Mk101 LOW BYPASS turbo-fans.[/quote]

The one illustrated in the video is a Buccaneer S2 with RR Spey turbofans, which is indicated by the larger intakes, as compared to the turbojet powered S1 model.

[quote]From:
http://en.wikipedia.org/wiki/Rolls-Royce_Spey

"Rolls then started work on a smaller engine otherwise identical in design, the RB.163 ( RB; Rolls Barnoldswick, after the original Rover works at Barnoldswick), using the same two-spool turbine system and a fairly small fan delivering bypass ratios of about 0.64:1. The first versions entered service in 1964, powering both the 1-11 and Trident. Several versions with higher power ratings were delivered through the 1960s, but development was ended nearing the 1970s due to the introduction of engines with much higher bypass ratios, and thus better fuel economy. Spey-powered airliners continued in widespread service until the 1980s, when noise limitations in European airports forced them from service."

See also:
http://en.wikipedia.org/wiki/Category:Low-...urbofan_engines

"Turbofan engines with a bypass ratio of less than 2 (usually less than 1)."  [/quote]

Very interesting, I'm sure …

[quote]Moving on to what I consider to be more relevant high-bypass turbofans and Boeings:
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http://www.memagazine.org/supparch/flight0...s/jetsfans.html

"P&W was also in the early competition to provide an engine for the large military transport specified in the Air Force's priorities review. P&W's initial prototype engine—the STF200—had a bypass ratio of only 2. Later versions increased the ratio to 3.5 with a lower turbine inlet temperature than GE's engine, the TF39. The STF200 had about 10 percent higher fuel flow than the TF39. The GE TF39, with its 8:1 bypass ratio, won the competition to power the large military transport, the C-5A, in August 1965.

While Pratt & Whitney certainly competed for the engine to power this transport, it never seemed to take the high bypass engine requirement seriously as evinced by its first demonstrator's bypass ratio being little more than that of the then-flying JT3D.

Perhaps corporate interest was absorbed in other efforts of commercial turbofan development, afterburning turbofan development (for the F-111), and a Mach 3+ turbojet engine development (for the SR-71). A few months after GE was selected to build the engine for the C-5A, Lockheed was selected over Boeing to build the aircraft.

While Lockheed and GE were consumed with making the C-5A work, Boeing and P&W teamed to build what became the 747 series of airliners. General Electric had an opportunity to bid a version of the TF39 for the 747, but GE management concluded that major modifications to the TF39 to meet the 747 requirement was too big a challenge while the engine itself was still in development.

It is interesting, though, to compare the P&W JT9D engine for the 747 to the one it offered for the C-5A. It had a bypass ratio of 5 instead of 3.5; not as high as GE's 8, but then the aircraft requirements laid down by Boeing dictated a lower bypass ratio than did the C-5A requirement. The JT9D had a turbine inlet temperature of 2,100°F, compared to 2,366°F for the TF39. The cycle pressure ratio was 24:1 compared to the TF39's 22:1. Not surprisingly, the engines have very similar characteristics.

Thus, by the late 1960s, the high bypass ratio engine was the engine of choice for aircraft flying long distances at high subsonic speeds (0.7 to 0.9 Mach). Aircraft of almost every kind have been powered by turbofan engines. High bypass turbofans have been built with many thrust levels—from less than 500 lbs. to more than 100,000 lbs."
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The video mentions that approximately "to even consider that Boeing might have used an 'FAA mandated airspeed safety margin' 'lower than 21%'" is "Beyond Stupidity." Aside from the obvious "ad hominem," [and the fact that I resent ANYONE telling me exactly what I MAY or MAY NOT be allowed to consider], my relatively brief searches only found the following semi-nebulous "airspeed safety margin" reference to:
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http://www.avioconsult.com/accidents.htm  [/quote]

Again, very interesting in terms of the trade-offs various design teams have to choose between to meet the specifications.
However, as stated previously, operating limitations are designed to prevent aircrews putting aircraft in the shop while the systems are comprehensively examined for any damage that may have occurred, not because damage is guaranteed to occur at those set limits.

[quote] "Boeing 737-200, Algeria 6 March 2003
Just after passing V1, an engine failed. Almost immediately after lift-off, control of the airplane was lost and the airplane crashed, killing all but one on-board.
AvioConsult reviewed the accident investigation report and concluded that the engine emergency procedures in the Flight Crew Training Manual are inappropriate because the recommended control inputs are not leading to the 10% airspeed safety margin over VMCA that aviation regulations require when an engine fails during takeoff.
When using the recommended control inputs (for keeping the wings level), the actual minimum control speed that the airplane experiences right after lift-off, will be much higher than the minimum control speed that was determined during flight-testing and that is used to calculate both V1 and V2. Actual VMCA was most probably even a little higher than V2 at the moment of lift-off; because the airplane continued a slow roll into the dead engine. After reading about the other accidents on this page, this will become clear.

Cause of the accident
The accident was caused by inappropriate engine emergency procedures. The pilots are not to be held responsible.

Boeing was informed by AvioConsult of a deficiency in the engine failure takeoff procedure, but Boeing insists that their 'guidance' is correct. But it is not.
Boeing most probably recommends to keep the control wheel level because otherwise the spoilers will extend to enhance, or in this case take over the roll control power. By doing so, a sideslip is accepted which reduces the climb performance even more. A problem is solved with another problem."
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I didn't find an "FAA Mandated Airspeed Safety Margin" above 10%, but perhaps it is in a handbook that I don't have access to as yet... [/quote]

Twin engined aircraft with widely spaced engines are notoriously difficult to control in the low speed regime that occurs at landing at take off when suffering asymmetrical loss of power or total engine failure. The same is true for Canberra, B-57, Meteor and many other aircraft with similar designs, which if you care to research them will tell a similar story. The usual cause of tragedy isn't lack of available power from the 'good' engine, so much as lack of time to put the recommended procedures into effect.

[quote]I also remember something posted about the F4 Phantom being of "standard aircraft construction"-- exactly which "standards" are being referenced? MIL-STD, MIL-HDBK, McDonnell Douglas, Boeing, DoD, NASA, FAR, FAA? [/quote]

Standard in the case referred to means ‘common’, i.e. the usual semi-monocoque construction employing frames, ribs, stringers and spars covered in aluminium alloy sheet (except for the post-afterburner hot end, which on the Phantom employed titanium and inconel x steel).
It is not a “special“ design such as something like the SR-71 for example could be termed.

[quote]Regarding the materials question, ASTM A36 strengths are listed as "240, 400"- a value without a unit is like a hammerhead without a handle in my opinion. Going to Wikipedia, I find these same values for A36 steel and 2014-T6 aluminum (at "400, 455"), with the units as Mega-Pascal (MPa) = 1E06 N/m^2. I didn't see any traceability in the video on what aluminum alloys were ACTUALLY used where in the Boeing airframes- do we KNOW that 2014 was used (and where) on AA11 and UA175? Do we have detailed wing and fuselage drawings from Boeing to analyze and model (likely requiring careful, verifiable FEA)? Do we have ANY blueprints for the South Tower for that matter?

From my research:
http://www.onlinemetals.com/steelguide.cfm
The minimum ultimate tensile strength of A36 steel is 58,000-79,8000 psi. The minimum yield strength is 36,300 psi.

http://www.aerospacemetals.com/aluminum.html#technical
You will find dozens of aerospace aluminum alloy options here. In absence of Boeing specifications, I randomly chose 6063-O aluminum, which lists an ultimate tensile strength of 13,000 psi and a yield strength of 7,000 psi.

Incidentally the "aerospace" page does not list 2014-T6 at the following:
http://www.onlinemetals.com/app_groups.cfm...2&id=5&app_id=5

Looking at the video referenced 2014-T6 aluminum (although I'm not certain why or more importantly, what shape the aluminum is from the video), I found ultimate tensile strength of 70,000 psi and a tensile yield strength of 60,000 psi. Of interesting note for 2014-T6 aluminum is the fatigue strength of 18,000 psi, but I don't recall the video discussing metal fatigue....

http://en.wikipedia.org/wiki/Fatigue_(material)
"Material Type. Certain materials, such as steel, will never fail due to fatigue if the stresses remain below a certain level. Other materials, such as aluminum, will eventually fail due to fatigue regardless of the stresses the material sees." See also "De Havilland Comet" and square aluminum windows. [/quote]

Which is why you no longer find any right angle corners in stress bearing areas on modern aircraft and drill round holes at the end of fatigue cracks.

[quote]This is from the marine industry, but hydrodynamics is considerably more demanding than aerodynamics in terms of force magnitudes and pressures due mainly to the relatively high compressibility of air.

http://www.kastenmarine.com/alumVSsteel.htm
"Built to the Same Standard

An aluminum hull structure, built to the same standards, weighs roughly 35% to 45% less than the same hull in steel. As a result, if high strength is of the highest priority, the alloy boat can be built to the same structural weight as the steel vessel, and then be considerably stronger.

This is less of an issue for larger vessels which are able to carry the necessary displacement for whatever materials choice is made. For smaller vessels however, the weight of the hull structure is very much an issue. For a small cruising vessel, say under around 35 feet or so, steel becomes less optimum, as one must resort to a large water plane and a large displacement to carry the weight of the structure.

When alloy is designed to the same standards as steel (ABS, Lloyds or other similar classification society), it is made to be higher in overall strength. The reason for this is that aluminum reaches its "endurance limit" sooner than steel in terms of flexure. Therefore the rigidity of structure (deflection) becomes the limiting design criteria for an aluminum structure, and this forces a higher than necessary overall yield and tensile strength.

With steel, one designs to the yield point of the material instead, since for steel, flexure and rigidity are not ordinarily a limiting issue. For steel therefore, the yield point of an "equivalent" structure will be considerably less, as we will see.

One advantage of steel is that between the yield point of mild steel (around 36,000 psi) and the ultimate tensile failure point (around 60,000 psi) there is quite a large plastic range (around 24,000 psi or roughly 40% of the ultimate strength), permitting a steel vessel to endure deflection without failure, so permitting considerable ability to absorb energy.

Scantlings

For alloy, the yield point and ultimate failure point of that "equivalent" structure (designed to the same standards of rigidity) turn out to be globally much greater for two reasons:

1) Aluminum 5083 H-116 plate, as an example, has a yield strength of around 34,000 psi and an ultimate strength of around 45,000 psi. We can see that the plastic range of aluminum is considerably less than steel (around 11,000 psi plastic range for aluminum, or roughly 24% of the material's ultimate strength).[

2) Since an aluminum structure is designed to a deflection criteria, all scantlings are made somewhere around 50% or so larger than they would be for a steel structure. For the sake of an easy example, what would be one inch of plate thickness on a steel vessel would be approximately one and a half inches of plate thickness on the aluminum vessel in order to achieve the same rigidity of structure.

Inch for Inch

Again, for the sake of an easy to follow comparison, we might say that "one inch" of steel plate will yield beyond its ability to recover its original shape at approximately 36k psi, and will fail at approximately 60k psi.

A "strength-equivalent" aluminum structure, having used deflection (stiffness) as the design criteria, will have been built using roughly 50% greater plate thickness. We might then say that this strength-equivalent "one and a half inch" thick aluminum plate will yield at around 51k per square inch of surface area (around 29% greater yield strength than the "equivalent" region of steel plate), and will fail at around 67.5k psi (around 12.5% greater ultimate strength than the "equivalent" region of steel plate).

Of course these broad generalizations are intended only as a way of illustrating the approximate relative strengths of the materials. However, from these considerations we can see that the aluminum vessel will have a greater overall strength than the steel vessel per square area of plate. The reason for this is that the aluminum plate will, for the sake of stiffness, be 150% the size of the steel plate.

The result in practical terms is that a boat built in aluminum will be far less easy to dent by running into stuff (roughly 29% higher regional yield strength), and will have a slightly higher resistance to ultimate failure (around 12.5%). As an added bonus, this means that the aluminum yacht will resist distortion all the better while being welded during construction. As an extra added bonus, the aluminum structure will weigh considerably less than the equivalent steel structure.

Dave Gerr has equated the two materials similarly, referring to a material's structural efficiency. By this, he means the ratio of a material's stiffness to the density of that material. Per those equations, aluminum is shown to have a "structural efficiency" much greater than steel. In more precise terms, for columns that are designed to an equivalent stiffness an aluminum column will weigh 57% of the equivalent column in steel. For beams and panels (frames and plating) designed to the same stiffness, an aluminum structure will weigh 48% of the equivalent structure in steel."
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How thick is our unspecified aluminum alloy wing skin? What is the cross-sectional wing profile? How thick is the unspecified alloy Boeing fuselage?[/quote]

You’ll have to check that with Boeing, or a certified maintenance engineer but that data is generally not publicly available, particularly the supercritical wing which Boeing developed in-house rather than using an off-the-shelf NACA section. Typically, aircraft skins are between 15 to 30 thou thick depending on the anticipated loads – although critical structural skins can include integral stiffening elements either machined or chemically milled in place.
As for section - “Sweepback angle and aspect ratio of the new 767-200 are 31.5° and 8.0, respectively, as compared with 35° and 7.1 for the 707-320B. These differences in wing geometry would be expected to increase aerodynamic efficiency by a small amount. Incorporated in the wing of the 767-200 is a new Boeing-developed supercritical-type airfoil section. The basic technology of the supercritical airfoil section was pioneered by Richard T. Whitcomb of the NASA Langley Research Center. Use of such sections allows increased wing thickness ratio without corresponding reductions in the Mach number at which large adverse compressibility effects begin to occur.”
http://www.globalsecurity.org/military/sys...rcraft/b767.htm

Also NIST NCSTAR1-2B Chaps1-8.pdf goes to some lengths in analysing the factors involved in the impacts.

I can’t help feeling that this portion of the topic is somehow veering into “this material shouldn’t be able to penetrate that material” fallacy though.

[quote] I prefer tangible, independently-verifiable sources when "clearly," "always," "never," "Beyond Stupidity," etc.-type statements are sweepingly made. I don't recall making any appeals to "common sense" in my posts above either- that is an increasingly rare commodity IMHO.[/quote]

I think you’ll find that the ‘common sense’ comment was aimed at a visiting NPT spear-carrier who briefly popped in to tell us his beliefs and show some evidence-free support.

[quote] I also likely won't be convinced of ANYTHING again by video (especially internet) without supporting EMPIRICAL data any time soon. I've been seeking Boeing and jet engine engineers' input for some time now, but from my research, they have been conspicuously silent (either pro- or anti-OCT) other than Joseph Keith and the female Boeing engineer on the telephone interview. If anyone can provide relevant Boeing design and test documents or ACTUAL instrumented B757 or B767 wind tunnel videos or test reports, then I would LOVE to see them post-haste (six years later)...

To conclude, I see two MILITARY jets that were HIGHLY MODIFIED for low altitude flight being offered as "evidence" of COMMERCIAL Boeing low altitude and velocity capabilities. I don't recall the video mentioning "ground effect" or air density vs. altitude and temperature either. Sorry, but no sale.... [/quote]

The illustrated aircraft (Buccaneer and Phantom) are not ‘highly modified’ at all.
There are obvious differences in design and construction to enable greater manoeuvrability, effectiveness in their roles and a longer fatigue life cycle in their anticipated service environments – neither of which points are particularly relevant in the unique events of September 2001.
There is no ground effect present when descending to an altitude of 1000ft in the case of the WTC.
As far as I know the only scenario it would have played a part is in the OCT’s lawn skim into the Pentagon

As for the rest, it boils down to Joseph Keith’s provably laughable claims (provable by the Boeing type documentation alone that is), and an anonymous “female Boeing engineer” clearly an employee non-committal enough to not give her name, job title or an opinion in anything other than the most general terms.

What Anthony Lawson’s video succeeds in doing is showing that unmodified jets can fly at high speed at low level without ‘shaking themselves to pieces’ and without the engines ‘choking’ – by which I assume is meant the intake
fan stalling - which would occur with airflow break-up when shockwaves began forming near Mach 1.

[quote]I noticed that an A. Lawson (this video's producer?) only made 4 posts over at the govt loyalist site before he referred to them as "a den of verbal thugs," and I agree WHOLE-HEARTEDLY with his assessment of that particular bunch (although I'd add "highly questionable" motives as well). Putting all that aside, at this point, I'd prefer to see SOURCED, verifiable, well-thought [written?] points made in/by the 9/11 TM (esp. in matters of our own differing opinions)- don't we ALL collectively have enough (MSM/opinion) hurdles to jump as it is and other demands on our time?

Sincerely,
d [/quote]

I agree, again.

[quote]P.S. (Also off-topic) I believe that "Dirty Harry" allegedly carried a S&W Model 29 .44 Remington Magnum (not a .357 Remington Magnum). While Clint & Harry Callahan were both uber-cool, the .44 Mag was not then (circa 1971) and is not now the "most powerful handgun in the world." [I'll let the reader do their own research here if deemed relevant.]

From Whackapedia again:

"Throughout the film Eastwood's Model 29 is lionized as an all-powerful instrument capable of sending assailants flying wildly through the air, while in reality the round is far less dramatic than depicted. The .44 Magnum round is not considered to be a practical caliber for urban police use due to excessive recoil (making target re-acquisition difficult) and over penetration issues, which greatly increases the likelihood the bullet going through targets and injuring bystanders.

The gun used by Clint Eastwood in the filming of the movie was reportedly not a .44 Magnum. According to a story related by a member of the studio's prop department, Smith & Wesson did not have a Model 29 in stock at the time one was requested for filming. Instead, they used a Smith & Wesson Model 57 in .41 Magnum.[citation needed] The Model 29 and Model 57 are identical except for minute differences in bore size, chamber dimensions, and exterior markings, none of which are visible in the film."  [/quote]

Interesting background. I should make clear however that my purpose was not accuracy in firearms identification, but rather to give some sense of scale of the impact forces. Not many people would have a reference point for the power of a single KJ, let alone over 3 million of them.

Regards, Chek

[chek]

Chek, The Sandia video proves absolutely nothing. Why? Were you present at the test site when the plane was being prepared? How on earth do you know it is an actual F4 Phantom and not a mere shell MINUS the engines, frame, landing gear or anything that could cause a slowing or crumpling? Why no closeup video after the water mist cleared (that's right, the Sandia 'F4' was filled with WATER!) to show what was left after the 'plane' impacted the wall?

The test was designed to determine impact damage, not cause a conflagration (a jet fuel cloud and blazing rocket motors are not a good combination) and the water ballast is a perfectly adequate substitute for fuel weight which contributes to the kinetic energy generated. The validity of the test was indeed questioned by a nuclear industry watchdog group, though not on any of the grounds you've mentioned. http://www.nci.org/02NCI/01/back-27.htm

There may well be more footage – though given the frame rates of high speed cameras that’s not guaranteed. In any case, the actual impact damage against a solid concrete block is of no real interest to our concern, which is impact against a relatively thinner steel structure.
It’s main value is in demonstrating the lack of ‘expected’ deceleration caused to the following rear part of the aircraft structure. It’s worth noting too that the tail section’s forward momentum continues straight and true even after the mid fuselage wingbox attachment point has been shredded (the rocket propulsion units can be seen attached under the wings).

It would have been interesting to see what was left of the 2 engines, frame and landing gear. Your willingness to accept the Sandia F4 video ON FACE VALUE leads me to believe that you are less than objective, after all, 911 was a false-flag hoax blamed on Arabs meant to fool the world. Hoaxes, you see, are the norm for the 911 perps and all evidence put forth by any government agency, defense contractor or mainstream media , all accomplices, should be heavily scrutinized. Below is a conference Sandia hosted in 2002. The guest list is a veritable "who's who" in the phony war on terror.

http://www.sandia.gov/news-center/news-rel...ec/siwconf.html
"Sandia to host Strategic Indirect Warfare Conference

ALBUQUERQUE, N.M. — An improved understanding of America’s war on terror both at home and abroad and its impact on our nation are among the goals of the Strategic Indirect Warfare 2002 Conference, Dec. 3-5 at the Albuquerque Marriott Hotel, 2101 Louisiana NE.

Hosted by the Department of Energy’s Sandia National Laboratories, the conference will bring together experts representing a variety of interests in government, industry, and academia, including the CIA, FBI, Office of Homeland Security, Rand Corporation, Department of Defense, and the author of Future War, Col. John B. Alexander. For more information on the conference, including an agenda with speakers and topics, please go to http://www.sandia.gov/SIW2002/.

“The conference will examine the impact of the changing nature of warfare on homeland defense requirements, and further, educate the public about the likely consequences,” said conference organizer Dick Burcham of Sandia National Laboratories.

“In the global war on terrorism, the enemy is waging a strategic indirect war,” Burcham added. “For the nation to prevail in this war, a better understanding of the nature and complexities of strategic indirect warfare will be required.”"

The impacted remains (in the case of the Sandia test) are irrelevant to this discussion, as the point of contention is the so-called ‘impossible’ appearance of the penetration of the Towers' outer façade. What happened after that to the WTC wreckage is a matter of forensic investigation and subsequent cover up.

As for the rest of your ‘guilt by association’ information, I don’t see how an empirical, recorded test is automatically suspect because of the nature of corporate industry, which drums up business wherever its available in whatever field is a growth area – in this case the never ending war on abstract concepts.

Then there is the Council On Foriegn Relations involvement in the radio broadcast hoax of H.G Welles "War Of The Worlds" whose purpose was a psychological test to find out how much faith the masses put in the media.
http://www.hourofthetime.com/warofthe.htm
"War Of The Worlds, was broadcast by Mercury Theater on the Air, from a microphone in a New York studio of the Columbia Broadcasting System. Council on Foreign Relations member Frank Stanton was a CBS executive. Stanton would direct Radio Free Europe. Regarding the programs realism Cantril writes, "The sheer dramatic excellence of the broadcast must not be overlooked. The unusual realism of the performance may be attributed to the fact that the early parts of the broadcast fell within the existing standards of judgment of the listeners..."

Further still are phony Osama videos, Nick Berg beheading video, bogus Pentagon 757 video and on and on. Yet, you BLINIDLY accept the Sandia video as legit? Chek, I have a car I want to sell you.....

Just as with the NIST technicians, I don’t view their work as corrupted. How their findings are selected and what use they’re put to in pursuit of a predetermined result in support of political policy is another thing altogether.

Question: Do you believe the Apollo lunar missions actually put a man on the moon in 1969? If you accept the lunar landings were faked that to do so, the perps made a phony lunar module, videotaped a phony landing, phony moon surface, phony photos and videos of "moon walks", etc, etc. And you don't think the 911 perps would fake an F4 Phantom crash in order to 'prove' what would happen when a 757 hits a building?

No I don’t believe the lunar landings were faked. All the evidence I’ve seen supporting the moon fakery argument is to my mind just as insubstantial as the plane fakery evidence, and I would imagine appeals to pretty much the same demographic.
Furthermore, I'd suggest that any damn fool anywhere can call anything whatsoever 'fake', should they want to do so.
Proving that to be the case is an entirely different thing.

[chek]

as far as I can see has been unsuccessful in the many and various attempts to prove video fakery so far."

You see the plane "enter" the building
It does not crumple, nor shred, it,s wings and tail, immutable, slicing through steel and concrete.
It explodes only after the entire plane is inside the building.
When you see that
It is fake. The laws of physics.
No airplane can do what the video shows it doing
ergo
The video is fake

partly right.

Hologrammes CAN do that, and they obey the law of physics.

http://u2r2h-documents.blogspot.com/2007/1...ram-theory.html
http://u2r2h-documents.blogspot.com/2007/1...-projector.html

Fly-By was caught in a photo:
http://u2r2h.blogspot.com/2007/08/david-thom-pictures.html

====

I just don't understand why you silly men don't employ sherlock holmsian logic?
If you exclude all other possibilities, whatever is left, however unlikely, must be the truth.

A) Have you satisfied yourself that a REAL 767 could not have flown? Yes.
B) Have you satisfied yourself that they couldn't have faked ALL videos AND PHOTOS showing a 767?

there is only one thing left, however unlikely!

(some sort of) hologramme (carrying - missile)


or do you want to dispute A) of B) again?

or am I oversimplifying it? i.e. is there a C) ???

Sherlock Holmes is a fictional character with a coke habit, and Conan-Doyle, his creator believed in fairies (which figures, I suppose).

As for attempting to use a fictional character’s quote as some sort of authoritative statement, don’t make me laugh.

[Quest]

Let's see, there is no TV fakery regarding 911, the moon landings actually took place, September Clues is an intentional "con". Sandia Labs would never lie.

Just keeping score so far, Chek. (IMG:http://pilotsfor911truth.org/forum/style_emoticons/default/wink.gif)

Chek, am I correct to assume you believe 911 was an inside job? I've always assumed that since you are on this site but maybe I'm wrong?

This post has been edited by Quest: Jan 7 2008, 11:07 AM

[chek]

You've made an accusation. September Clues is an intentional "con", correct? Am I to understand you saw a check with Uncle Sam's name on it fall out of the pocket of the maker of Sep Clues?

Time to put up or shut up. Where's your proof?

BTW, have you seen the Sep Clues latest video that CLEARLY demonstrates the Naudet brother's video was deliberately tampered with to show the gash being wider than it actually was? Also, this video proves that the wings of a Boeing 767 (or plane as large as a 767) were not the cause the gash but rather it was the work of planted charges.

http://www.livevideo.com/socialservice

Care to comment?

I have no idea what Simon 'not his real name' Shack's motivations are, but one thing I am sure of is that forcing a real investigation will rely on good solid evidence and not substandard, poorly researched bastardised music videos.

I'm glad you brought up his new effort.
What exactly is a'linear explosion' anyway?

And how is it any different to the bright orange initial fuel explosion?
And why is it suspicious that there's a delay?
Has Shack calculated the timings of the multiple fuel tank ruptures and worked out when the fuel air mixture became explosive?
I should cocoa.
And how did pre-placed charges exactly at the point of impact delay their detonation?

But hey don't ask questions, because socialdisservice is the no planes number one video king!

He then informs us that 'at least 10' vertical columns to the right - 30% of the Tower wall - is intact. Even cursory research would have indicated to him that there are 59 columns per side of the Towers. I guess his arithmetic skills are about on a par with his research skills.

Not content with that, he goes on to claim that what better resolution photos show to be a smoke stain extending to the right edge of the north face (and is therefore a contrast video artefact) is in fact a 'photoshopped cut' covertly inserted to widen the wingspan to be consistent with a B767.

Leaving aside why anybody would use a still image tool like Photoshop to fake movie footage, nobody has ever claimed the impact hole extended to the full wingspan of the jet.

I'd guess like most of his target audience he's never examined other photos and the patiently constructed damage maps in the NIST reports. And Killtown, allegedly a champ "researcher", with no regard to his own credibility, praises this garbage as 'a good catch'.

There's more, but its unnecessary to go further.
Shack is a liability both to your own no plane cause and 911 Truth in general.

[chek]

Let's see, there is no TV fakery regarding 911, the moon landings actually took place, September Clues is an intentional "con". Sandia Labs would never lie.

Just keeping score so far, Chek. (IMG:http://pilotsfor911truth.org/forum/style_emoticons/default/wink.gif)

Chek, am I correct to assume you believe 911 was an inside job? I've always assumed that since you are on this site but maybe I'm wrong?

To be clear;
there's no undeniable evidence that technical TV was used on 911 (TV fakery exists at the editorial level, not the technical imho);

the moon landings occured. Again, as there is no undeniable evidence that they didn't;

your feeble insinuation that Sandia might have lied over 10 years in advance in support of your case is about as threadbare as sole evidence gets.

Yeah, it sure helps me keep score of who's interested in serious research too.

What any of the above inconsequential fluff has to do with 911 being an obvious inside job is a mystery to me.

[Quest]

Check wrote,

"No I don’t believe the lunar landings were faked. "

I knew you were going to say that. (IMG:http://pilotsfor911truth.org/forum/style_emoticons/default/wink.gif)

Chek,

I still have not yet heard you say 911 was an inside job. Is that what you believe? If so, what do you base that belief on?

This post has been edited by Quest: Jan 7 2008, 12:39 PM

[chek]

Check wrote,

"No I don’t believe the lunar landings were faked. "

I knew you were going to say that. (IMG:http://pilotsfor911truth.org/forum/style_emoticons/default/wink.gif)

Chek,

I still have not yet heard you say 911 was an inside job. Is that what you believe? If so, what do you base that belief on?

Tell you what Quest, I've a better idea.

You tell me the name of one credible person (who isn't connected to Murdoch) who promotes moon landing fakery, their compelling evidence and also why you think it's wise to associate said quackery with 911 Truth, and I'll answer your question.

[Quest]

Check wrote,

"No I don’t believe the lunar landings were faked. "

I knew you were going to say that.  (IMG:http://pilotsfor911truth.org/forum/style_emoticons/default/wink.gif)

Chek,

I still have not yet heard you say 911 was an inside job. Is that what you believe? If so, what do you base that belief on?

Tell you what Quest, I've a better idea.

You tell me the name of one credible person (who isn't connected to Murdoch) who promotes moon landing fakery, their compelling evidence and also why you think it's wise to associate said quackery with 911 Truth, and I'll answer your question.

That would be me, BoneZ and many others right here on this site for that matter, including several admins. If you don't believe me, you are welcome to ask around. Eventually I may explain the relevance of the Sandia F4 'test' and the lunar 'landings' if I find you are worth the time but things aren't looking good so far. ;-)

Since we are on your history, what do you make of the killings of JFK, MLK and RFK? If we are going to be friends I think it's a good idea to establish each other's credibility, no? BTW, I still haven't yet heard your answer regarding 911. Inside job? Yes or no?

This post has been edited by Quest: Jan 7 2008, 02:43 PM

[chek]

Check wrote,

"No I don’t believe the lunar landings were faked. "

I knew you were going to say that.  (IMG:http://pilotsfor911truth.org/forum/style_emoticons/default/wink.gif)

Chek,

I still have not yet heard you say 911 was an inside job. Is that what you believe? If so, what do you base that belief on?

Tell you what Quest, I've a better idea.

You tell me the name of one credible person (who isn't connected to Murdoch) who promotes moon landing fakery, their compelling evidence and also why you think it's wise to associate said quackery with 911 Truth, and I'll answer your question.

That would be me, BoneZ and many others right here on this site for that matter, including several admins. If you don't believe me, you are welcome to ask around. Eventually I may explain the relevance of the Sandia F4 'test' and the lunar 'landings' if I find you are worth the time but things aren't looking good so far. ;-)

Since we are on your history, what do you make of the killings of JFK, MLK and RFK? If we are going to be friends I think it's a good idea to establish each other's credibility, no? BTW, I still haven't yet heard your answer regarding 911. Inside job? Yes or no?

An extremely slim content free answer, but to answer your question re: inside job in the same vein, you need only have read my post at 3.02 above.

And the JFK, RFK and MLK assassinations were the founding and establishing acts of the right wing era we still live under.

[rob balsamo]

Quest,

Do me a favor, do not speak for others or our organization. Please read the bold sentence at the very top of this forum and our mission statement on top of our home page at http://pilotsfor911truth.org. Pay specific attention to the underlined sentence. Thanks.


Rob

[Quest]

Check wrote,

"No I don’t believe the lunar landings were faked. "

I knew you were going to say that.  (IMG:http://pilotsfor911truth.org/forum/style_emoticons/default/wink.gif)

Chek,

I still have not yet heard you say 911 was an inside job. Is that what you believe? If so, what do you base that belief on?

Tell you what Quest, I've a better idea.

You tell me the name of one credible person (who isn't connected to Murdoch) who promotes moon landing fakery, their compelling evidence and also why you think it's wise to associate said quackery with 911 Truth, and I'll answer your question.

That would be me, BoneZ and many others right here on this site for that matter, including several admins. If you don't believe me, you are welcome to ask around. Eventually I may explain the relevance of the Sandia F4 'test' and the lunar 'landings' if I find you are worth the time but things aren't looking good so far. ;-)

Since we are on your history, what do you make of the killings of JFK, MLK and RFK? If we are going to be friends I think it's a good idea to establish each other's credibility, no? BTW, I still haven't yet heard your answer regarding 911. Inside job? Yes or no?

An extremely slim content free answer, but to answer your question re: inside job in the same vein, you need only have read my post at 3.02 above.

And the JFK, RFK and MLK assassinations were the founding and establishing acts of the right wing era we still live under.

That's fine chek. Regarding TV fakery then, we can agree to disagree, I have no problem with that. As far as the lunar landings go, believe what you wish, I've done my research and am satisfied with my conclusion.

[Quest]

Quest,

Do me a favor, do not speak for others or our organization. Please read the bold sentence at the very top of this forum and our mission statement on top of our home page at http://pilotsfor911truth.org. Pay specific attention to the underlined sentence. Thanks.


Rob

Sorry Rob, no harm meant.

[chek]

That's fine chek. Regarding TV fakery then, we can agree to disagree, I have no problem with that. As far as the lunar landings go, believe what you wish, I've done my research and am satisfied with my conclusion.

Believe me when I say I've done my research too Quest, but have come to different conclusions.
Agreeing to disagree is probably the best course.

regards, chek

[Quest]

That's fine chek. Regarding TV fakery then, we can agree to disagree, I have no problem with that. As far as the lunar landings go, believe what you wish, I've done my research and am satisfied with my conclusion.

Believe me when I say I've done my research too Quest, but have come to different conclusions.
Agreeing to disagree is probably the best course.

regards, chek

I can respect that. (IMG:http://pilotsfor911truth.org/forum/style_emoticons/default/thumbsup.gif)

[dMz]

[QUOTE=chek,Jan 7 2008, 07:22 AM]
A.
The ability for aircraft to operate at low level without airframe 'disintegration' or engine ‘choking’, which is the point of the exercise is successfully demonstrated in the video.
...
B.
That is true as far as it goes – but it eloquently demolishes Joseph Keith’s assertion that the airframe would ‘shake itself apart’ before the documented max. gear down speed was attained, and that the engines would ‘choke' on the thicker air at low altitude’.
‘Thicker air’? The correct term a professional would use is ‘denser’, which may or may not be a further signifier of Keith's credibility.
...
C.
Yes, x1.15 is the mph to knots conversion formula. Even the RAE Farnborough (where they know a thing or two about aviation) ‘guesstimates’ were estimations based on the evidence available to them at the time. Given FFG’s previous supersonic interpretations of the radar records, I’ll pass on your interpretations and stick with the professional’s estimations until such time as harder evidence becomes available. No offence.
...
D.
Regardless of your research whose thoroughness we can only speculate on, apparently they did.
It should be noted that the purpose of the quoted limitations (in addition to passenger safety) are to enable quick turnaround to get commercial jets back in the air and earning asap. Exceeding handbook limits and popping strain gauges and/or rivets causing various possible categories of damage will result in hangar time and a displeased management. This wasn’t a major concern of the flight planners on that day.
...
E.
Mach isn’t so much an absolute speed as a variable one depending on conditions – relating to when compressibility shockwaves begin to form - and depends on temperature and, particularly at low level, humidity.
At sea level at a temperature of 15C, Mach 1 is approx 760mph, but the curved surfaces around an airframe will induce local airflow to exceed the actual forward speed of the vehicle in some areas.
Mach 0.86 is 650mph at sea level but 560 mph at 30,000 ft.
http://en.wikipedia.org/wiki/Mach_number
500+mph is well below either figure.
-----
F.
"The small wing of the Buccaneer is suited to high-speed flight at low level. Such a wing, however, does not generate the lift that is essential for low-speed carrier operations. Therefore, the wing and horizontal stabiliser are "blown" by bleeding compressor gas from the engine through surface vents. A consequence of the blown wing is that the engines are required to be run at high power for low-speed flight (in order to generate sufficient compressor gas for blowing). Blackburn's solution to this seemingly counter-productive situation was to provide a large air brake. The tail cone was formed from two leaves that could be hydraulically opened into the airstream to decelerate the aircraft."
-----
Does a COMMERCIAL B757 or B767 have ANY of these aerodynamics or engine characteristics?[/QUOTE]

The designs differ according to their anticipated operating environments. The buffet induced fatigue life of a B767 at low level would be very short as that’s not what it’s designed for. Prolonging the aircraft’s service life was a hardly a factor to the 911 planners.
...
G.
The Buccaneer employs 36 inch diameter Spey turbofans using exactly the same plain pitot type intakes as the B767. The difference in size is hardly an issue, as the intakes of each are optimised to cope with the mass flow of air through each engine.
...
H.
I can’t help feeling that this portion of the topic is somehow veering into “this material shouldn’t be able to penetrate that material” fallacy though.
...
I.
The illustrated aircraft (Buccaneer and Phantom) are not ‘highly modified’ at all.
There are obvious differences in design and construction to enable greater manoeuvrability, effectiveness in their roles and a longer fatigue life cycle in their anticipated service environments – neither of which points are particularly relevant in the unique events of September 2001.
There is no ground effect present when descending to an altitude of 1000ft in the case of the WTC.
As far as I know the only scenario it would have played a part is in the OCT’s lawn skim into the Pentagon
...
J.
As for the rest, it boils down to Joseph Keith’s provably laughable claims (provable by the Boeing type documentation alone that is), and an anonymous “female Boeing engineer” clearly an employee non-committal enough to not give her name, job title or an opinion in anything other than the most general terms.

What Anthony Lawson’s video succeeds in doing is showing that unmodified jets can fly at high speed at low level without ‘shaking themselves to pieces’ and without the engines ‘choking’ – by which I assume is meant the intake
fan stalling - which would occur with airflow break-up when shockwaves began forming near Mach 1.

[/QUOTE]
Hi chek,

A. The alawson911 "Busted! orange" video suggests that 2 MILITARY aircraft (both design-optimized for low level flight with "blown", vented small wings in the B-103 Buccaneer, or HIGHLY MODIFIED in the case of the 1 of 2 survivable F4 Phantom "Sageburners" with Boundary Layer Control added- perhaps you need to re-read the link I provided earlier) can fly at the referenced speeds (and altitude in the F4 "Sageburner" case, which is helpful). I don't think I ever used the term "choking," but I and Omega892 were discussing the high speed/low altitude thing over on the UA175 thread here (since that was allegedly and apparently the highest of the 4 Boeing aircraft velocites, based upon USAF DATA).

Here's another video of a [MILITARY] "aircraft" actually AT SEA LEVEL:
http://www.alexisparkinn.com/photogallery/...kwaterseals.wmv

Does it demonstrate anything CONCLUSIVE about commercial Boeing transport airliners? I think not... Even the specially-designed B-103 Buccaneer would be hard pressed to operate in this "flight envelope" IMHO.

B. Wasn't Joseph Keith a Boeing engineer talking about commercial transports, NOT McDonnell Douglas F4 Phantoms and B-103 Buccaneers? As to the "software engineer" allegations, would a modern "fly by wire" B777 and B787 even get off the ground without many hours of software development and testing? I'm fairly certain that hardware and software need to work synchronously together, even at Boeing, though I haven't worked for them in Everett, WA.

C. Just to be clear, is this an aspersion that you are casting personally against me? Is it "guilt by association"? I was working from actual USAF 84 RADES data, not grainy internet videos- I believe that data analysis is the more scientific of the 2 approaches. There is a 24-page thread in the UA175 section here on the RADES "mach" findings, if you care to research it, and I didn't choose the term "mach" if you'll notice.

D. As I stated earlier, my "speculatively thorough" [apparently according to you] research is based upon FAA and FAR regulations, since Boeing hasn't been exactly open for the last 6 years.

http://pilotsfor911truth.org/forum...post&p=10393891

"It should be noted that the purpose of the quoted limitations (in addition to passenger safety) are to enable quick turnaround to get commercial jets back in the air and earning asap"-chek. Have you worked for Boeing, FAA, or on the FAR code then?

"Exceeding handbook limits and popping strain gauges and/or rivets causing various possible categories of damage will result in hangar time and a displeased management."-chek. Is this ALL it will do to a commercial Boeing B757 or B767 operated at 586 mph at 700-1500 feet AMSL? Can you please provide some supporting Boeing, engine manufacturer, or official (FAA, FAR, EU?) documentation or test data to support this statement? How can you be so certain of the "flight planners'" intentions (and exactly which persons do you mean here)? I'm sorry, but your three unsupported statements are highly speculative in my opinion.

E. Thank you for the primer on mach number, but I think I had it covered here already back on Dec. 2, 2007.

http://pilotsfor911truth.org/forum...post&p=10396594

F. Did you miss the "small wing[s] and horizontal stabiliser[s]" that "are "blown" by bleeding compressor gas from the engine[s] through surface vents" on the B-103 Buccaneer? Do I get to see this video next as "proof" of commercial Boeing capabilities?

http://www.youtube.com/watch?v=4y_ePf1Jcr8

G. "The difference in size is hardly an issue, as the intakes of each are optimised to cope with the mass flow of air through each engine."- chek. That MIGHT be true, WITHIN the DESIGNED operating parameters for the respective turbofan engines (of which Boeing has at least 4 different supply companies). I'll let the reader do his own calculus here, but the incoming fan airflow is mainly a function of air density, intake area, and engine "forward" velocity.

http://www.lerc.nasa.gov/WWW/K-12/airplane/turbfan.html

Comparing the 36-inch B-103 low-bypass turbofan to say a 94-inch (approximately the smaller of the Boeing engines from what I recall- It's a "back of the napkin" calculation) high-bypass Boeing turbofan engine, I get an area ratio of 324/2209 = 0.1466727026 for the B-103, or inversely 6.8179012346 TIMES the mass airflow intake volume for the [smaller of the] Boeing turbofans at equivalent air density and airspeed... "Hardly an issue"??? Are you certain "choking" would be the problem here? (Of course, I'd like to see supporting Boeing engine documentation in your answer).

Now the 1 of the 2 F4 Phantom "Sageburners" used two J79-GE-3A turbojets HEAVILY MODIFIED with Boundary Layer Control added from what my "speculatively thorough" research indicates- correction or refutation is welcome and requested on this one point, sir.

H. I personally don't consider materials science a "fallacy"- I've even used it to earn a living before. Are you REALLY going to quote NIST on a 9/11 Truth website to me? Can you please point out which relevant pages of the nearly 10,000 NIST report(s) pages support your aluminium "penetration theory." Yes, I've heard, KE=1/2m*v^2, or KE=p^2/2m, and F=ma... Been there, done that... Please reverse your frame of reference and explain what 586mph WTC perimeter column(s) would do impacting a stationary B767-200 sitting on a runway in a "perpendicular" strike-- the Law of Conservation of Momentum really doesn't care which object is stationary. Relative velocities and reference frames are the relevant concepts in collisions in my [scientific] opinion. I can find you some sources if needed here...

There is a little more involved in shear, "plug," and penetration calculations than KE, momentum, and velocity. I believe that the NIST report was based upon FEA computer simulations, and I have alluded to GIGO "garbage in, garbage out" before (it is a computer industry term, I didn't make it up). If Joseph Keith was only a Boeing software engineer, why exactly are NIST's software engineers any better in matters of materials science and structural engineering? I asked for Boeing design specifications about the aluminium since they weren't in the alawson911 video that I watched at your link, and I haven't seen them yet. The "2014-T6" aluminium in the alawson911 "Busted!" video seems a little arbitrarily fallacious to me.

I. See above. Also, military aircraft are designed to much different standards than commercial aircraft (here in the USA at least). FYI- I've read much of the DoD, NASA, and MIL-STD documentation that apply to aerospace, but I refuse to be held accountable for RAF aerospace standards as I'm not British. I believe that I can find you a guy who does know RAF aerospace standards here at P4T, though.

J. "...provably laughable claims (provable by the Boeing type documentation alone that is)"- chek. Which portion of the "Boeing type documentation" do you mean and where can I find those? I've only read the DOT/FAA Type Certificate Data Sheets for the B757 and B767 regarding this topic- I've linked those under the "Aircraft" thread here at P4T. Also, my research indicated that your "anonymous" Boeing engineer is named Lori Bechtold, as I recall, but you're certainly welcome to do your own research if mine is "speculative" as you say. If you have issues with Joseph Keith and Lori's statements, please take those issues up with them- I'm just the messenger here.

Conclusion:
"What Anthony Lawson’s video succeeds in doing is showing that unmodified jets can fly at high speed at low level without ‘shaking themselves to pieces’ and without the engines ‘choking’ – by which I assume is meant the intake
fan stalling - which would occur with airflow break-up when shockwaves began forming near Mach 1."- chek

I agree up to the dash after 'choking', except for the "unmodified" in the case of the F4H Phantom II specially-modified "Sageburner" variant (of which 50% fatally crashed, I believe, and one still holds that record for low altitude high-speed flying). In case you missed my point(s) earlier, how EXACTLY does a specially-designed B-103 Buccaneer bomber and a BLC-modified F4H Phantom II "Sageburner" variant fighter/bomber have relevance to commercial transport Boeing airliners (presumably loaded with fuel and cross-country fuel)?

Since this thread is becoming a tedious DISTRACTION for me, let me list it out for you:
1. PROOF of B757 and B767 commercial passenger transport "extreme" flight capabilities above design limits involves BOEING 757 and 767 commercial passenger transport aircraft specifically.
2. As you pointed out, air "density" affects the aerodynamics of various aircraft in drastically different, very complicated ways (which I believe is the main reason for wind test tunnels in the first place).
3. Military jet aircraft are NOT commercial Boeing passenger transport aircraft.
4. Boeing military KC-767 tankers are NOT commercial Boeing passenger transport aircraft.
5. Aircraft velocity specifications SHOULD include a reference to altitude and atmospheric conditions to be informative.
6. I never used the word 'choking' outside of quoting you and alawson911's "Busted!" video.
7. I am reasonably educated and qualified to speak on matters of mathematics, physics, chemistry, various engineering disciplines, and materials science. Whether or not you choose to recognize and believe that fact is entirely up to you.
8. Video (especially internet) is not entirely conclusive evidence (but perhaps I hold "evidence" to a higher standard than some).
9. I am not part of any "smoke raising, hand waving no plane posse." Perhaps if you would address respondees directly, it would save some ambiguity. I am an INDEPENDENT researcher looking for FACTS from MANY of the angles of 9/11 research. If various theories and hypotheses are proven erroneous, so be it.
10. I speak only for MYSELF, not any "pet theory" group, the 9/11 Truth Movement, or even Pilots For 9/11 Truth proper. Any assumptions made about my "positions" on various matters remain just that- assumptions.

Good day sir,
d

P.S. I had a computer/ISP outage disrupt the quote function somehow.