An UNMODIFIED Boeing 767 cannot fly @ 510 knots @ Sea Level. (hoax)

NewAgeMan
Then what is the basis for the opposition, including the "reasoning" and premise by which you moved the thread, and re-titled and re-edited the OP - relative to the data as it's been presented?

That's been explained.

Thus i can't think of any other reason why someone, particularly a scientifically minded "skeptic" would be so opposed to it or willing to go to any lengths to try to deny or refute, it makes no sense if one is supposed to be looking at the data as it really is with an objective, analytical mindset.

I can think of a reason: the premise lacks any compelling basis in reality such that no scientifically minded skeptic outside the ranks of "9/11 Truth" is able to find it worthy of their time. But the implication that, just because someone doesn't believe this/you/them, they suddenly support the "Official Story." Ludicrous.


If this had legs of any kind, serious investigative reporters -- at least in the foreign press -- would be all over it like they are Snowden. The NSA conspiracies prove that the press is not averse to taking on what has been previously conspiracy theories.

SkepticOverlord

NewAgeMan
Then what is the basis for the opposition, including the "reasoning" and premise by which you moved the thread, and re-titled and re-edited the OP - relative to the data as it's been presented?

That's been explained.

It didn't make any sense however, and was an entirely faulty premise, just for the record.

"Hoax"?

Rebuttal/Objection.


Edit to add:

SkepticOverlord

If this had legs of any kind, serious investigative reporters -- at least in the foreign press -- would be all over it like they are Snowden. The NSA conspiracies prove that the press is not averse to taking on what has been previously conspiracy theories.

Although that's not really a rebuttal to the implications of the data itself, since it's based on a "belief" and an assumption, this was my reply to that (see link below), when you raised it earlier as a way of saying, in effect it cannot be what it is, or the international press would pounce on it and it would have "legs" or in other words, because the info appears to be "fringe" and not widely accepted or understood, that it can't be right, although i can't see how that would in any way detract from or somehow undermine the validity of the data itself.

LINK
www.abovetopsecret.com...

reply to post by NewAgeMan


no that doesnt sound right.. are you reading the two documents i posted??

EAS is concerned about a certain amount of air passing the airframe regardless of altitude

TAS is concerned about the speed of air particles passing the airframe regardless of altitude

the documents have been indicating that TAS (the speed at which particles are passing over the airframe) is the major concern for flutter.. ie. not the amount of particles but the speed..

you saying something like "represents as an EAS (equivalent airspeed) of 722 knots or 1.19M, at 22,000 feet," is misleading.. the TAS of flight 175 was around 510knots TAS at 700feet which is roughly equal to 510knots EAS at 700 feet..

and although 510K EAS at 700feet has the same amount of air particles passing over the airframe when flying at 510K EAS at 22000 feet the speed at which each particle is passing the airframe is 722K .. flight 175 was not flying anywhere close to 722K at 700feet.. the speed at which air was passing the airframe was 510K

Both documents that i have linked to are indicating that the critical flutter speed is relatively fixed (or more accurately decreases with increasing altitude), depending on the aircrafts inertia.. and also that the speed at which air passes over the airframe is the most important factor regarding flutter thus the comments:

Many people apply a "constant true airspeed" rule that is much too severe
and
It is directly related to True Airspeed - the velocity of the air passing by the air frame.

your use of comparing EAS at 700 feet and at 22000 feet to show dynamic pressure is misleading.. from what i am reading from both the documents EAS (although related to TAS) has little to do with flutter speeds..

you should be comparing TAS at 700feet and at 22000feet to work out if it should have passed the critical flutter speeds.. and given that the TCDS indicates that a safe TAS of 552K TAS is maximum velocity through air, its well beyond 510knot TAS at 700feet..

catastrophic structural failure due to flutter is not the issue here.

choos

and although 510K EAS at 700feet has the same amount of air particles passing over the airframe when flying at 510K EAS at 22000 feet the speed at which each particle is passing the airframe is 722K

Your saying in effect the same thing while also trying to confuse the issue.

EAS is defined as:
EAS is the airspeed at sea level which produces the same dynamic pressure acting on the airframe as a True Airspeed at higher altitudes. It is used for determining aircraft performance, structural integrity.. .etc. The Vd limit is expressed in an EAS. In other words, to be more specific, 510 knots at sea level (EAS) would produce the same dynamic pressure as 722 knots True Airspeed (TAS) at 22,000 feet.

Do you understand what kind of airspeed that is, say in relation to the near Vd precedents (in the case of Egypt Air 990, 5 knots over Vd), not only at 22,000 feet but as you go higher as the air increasingly thins..whereby at 30,000 feet the air is 2/3rds thinner than near sea level?

The only way to understand the relative aerodynamic pressures involved due to airspeed is to understand EAS which is directly tied to TAS as altitude increases or decreases. There is no decoupling EAS from TAS when trying to grapple with the airspeed involved.

Yes, it's all about the amount of air passing across the airframe in determining aerodymamic pressure due to airspeed. Planes fly through air.

There's no denying either that the plane was 90 knots over it's Vd and 150 knots over it's Vmo - you can't move that bar nor alter that fact, as much as you would like to, nor the fact that 420 knots Vd becomes an increasingly harder limit as you descend from 17,800 feet to near sea level where the air is increasingly thicker (more air particles).

Why do you think they use Vmo/Mmo (360K/.86M) and Vd/Md (420K/.91M)?

It's important when distinguishing these types of things to... choos wisely, with clarity, honesty and integrity, which also goes to credibility.

NewAgeMan

Your saying in effect the same thing while also trying to confuse the issue.

sorry i actually missed the most important part to that statement..

the speed at which air is passing the airframe for flight 175 was 510Knots.. not 722Knot..

remember flutter is concerned about the speed of air passing the airframe (TAS) it is not concerned about the amount of air passing the airframe (EAS)

p.s. i am not debating controllability, my concern is flutter.. the aircraft should not experience catastrophic failure of the airframe as you have been trying to say..

reply to post by choos


As far as dynamic pressure is concerned, 510 knots near sea level is the equivalent airspeed of 722 knots TAS at 22,000 feet, that's a true statement.

And yes, near sea level, TAS CAS and EAS become close to being one and the same.

Relative to Vmo/Mmo and Vd/Md, it's still NINETY knots over Vd and 150 over Vmo.

The EAS is used to understand the relative difference in dynamic pressures between low vs. high altitude.

We're going 'round in circles here, this has all been covered rather thoroughly by now.

Instead of trying to move the bar in terms of aerodymamic pressure equivalency, why not focus on the nature of Vd or how far an aircraft can be expected to exceed it, and feel free to use any of the super fast precedents like EA990, China Air 006, TWA 841, the DC-8 flight test (the best of the precedent examples). In other words, instead of trying to falsify what's true and real, why not try to show that it's not without precedent as i've claimed.

Edit to add:

choos

p.s. i am not debating controllability, my concern is flutter.. the aircraft should not experience catastrophic failure of the airframe as you have been trying to say..

I have not really said that choos, only that the plane cannot FLY at 700 feet alt. as observed, unless seriously modified, and another aircraft altogether, both in terms of structure, control surfaces, avionics (including remote piloting hardware if not UA175) and with greater engine power and performance (to account for it's acceleration, post dive, to maintain it's 510 knot airspeed, near sea level).

Cannot FLY also includes controlled flight, without incurring any loss of flight control or any signs of structural failure.

Then when we're done, i'll challenge you to put a pilot in that aircraft who's never flown the real deal, and who was no better trained, experienced or skilled than his friend Hani Hanjour of Pentagon plane fame.

Best Regards,

NAM

NewAgeMan

choos

and although 510K EAS at 700feet has the same amount of air particles passing over the airframe when flying at 510K EAS at 22000 feet the speed at which each particle is passing the airframe is 722K

Your saying in effect the same thing while also trying to confuse the issue.

EAS is defined as:
EAS is the airspeed at sea level which produces the same dynamic pressure acting on the airframe as a True Airspeed at higher altitudes. It is used for determining aircraft performance, structural integrity.. .etc. The Vd limit is expressed in an EAS. In other words, to be more specific, 510 knots at sea level (EAS) would produce the same dynamic pressure as 722 knots True Airspeed (TAS) at 22,000 feet.

Do you understand what kind of airspeed that is, say in relation to the near Vd precedents (in the case of Egypt Air 990, 5 knots over Vd), not only at 22,000 feet but as you go higher as the air increasingly thins..whereby at 30,000 feet the air is 2/3rds thinner than near sea level?

The only way to understand the relative aerodynamic pressures involved due to airspeed is to understand EAS which is directly tied to TAS as altitude increases or decreases. There is no decoupling EAS from TAS when trying to grapple with the airspeed involved.

Yes, it's all about the amount of air passing across the airframe in determining aerodymamic pressure due to airspeed. Planes fly through air.

There's no denying either that the plane was 90 knots over it's Vd and 150 knots over it's Vmo - you can't move that bar nor alter that fact, as much as you would like to.

It's important when distinguishing these types of things to choos wisely, with clarity, honesty and integrity which goes to credibility.

Air pressure has nothing to do with it air temperature does an aircraft has a more difficult time going to mach one at 30000 then it does sea level like i said military pilots say the ride is much smoother. What it is is the colder the air the faster it can move It sounds strange but think of it like this the warmer the air the more it expands or the more space it takes up cold air has a higher density much like water turning to ice. Warm air actually puts less pressure on something like a wing because its lighter than cold air. This is why warm air rises like a hot air balloon the air outside the balloon is denser than the air in the balloon. It is less stress on an airframe to fly through lighter air does that make sense to you? This is the main reason i knew when i first read this it was wrong because of physics. If a plane can fly mach .80 at 30000 it can definitely do it at sea level well just above it to close to the ground you'll create a vortex.

reply to post by NewAgeMan

Why do you think they use Vmo/Mmo (360K/.86M) and Vd/Md (420K/.91M)?

regarding flutter speeds.. im not an aeronautical engineer so i dont know, my guess is to keep is simple for pilots.. its why EAS/CAS exists in the first place..

www.vansaircraft.com...
quest.arc.nasa.gov...

both these documents indicate that flutter speed is relatively constant TAS, or to be more precise flutter speed DECREASES with INCREASING ALTITUDE

and M0.91 at 22000 feet (the listed limit on the TCDS) is 554K TAS..

if flutter speed decreases with increasing altitude, it will increase with decreasing altitude.. so its safe to assume the flutter speed of a 767 at 700feet is more than 554Knots..

this is concerned primarily with flutter speeds NOT controllability.. EAS has little importance with regards to flutter speeds and is only an indication of controllability for pilots..

so catastrophic failure of the airframe due to flutter is not the concern here.

reply to post by choos


The Vmo/Mmo is still 360k/.86M and the Vd/Md is still 420K/.91M, and air density or the total amount of air passing over the airframe is greater near sea level than at altitude, which is why the plane can cruise at .86 Mach at 35,000 feet +

NewAgeMan
reply to post by choos

 

As far as dynamic pressure is concerned, 510 knots near sea level is the equivalent airspeed of 722 knots TAS at 22,000 feet, that's a true statement.

yes its true.. but its not an indication of what is happening at 700feet.. you are misleading people with such a statement.. at 700feet air is not passing the airframe at 722knots it is passing the airframe at 510knots..

And yes, near sea level, TAS CAS and EAS become close to being one and the same.

Relative to Vmo/Mmo and Vd/Md, it's still NINETY knots over Vd and 150 over Vmo.

The EAS is used to understand the relative difference in dynamic pressures between low vs. high altitude.

EAS/CAS is used by pilots, it measures how much air is passing the airframe not the speed at which air is passing the airframe..

We're going 'round in circles here, this has all been covered rather thoroughly by now.

Instead of trying to move the bar in terms of aerodymamic pressure equivalency, why not focus on the nature of Vd or how far an aircraft can be expected to exceed it, and feel free to use any of the super fast precedents like EA990, China Air 006, TWA 841, the DC-8 flight test (the best of the precedent examples). In other words, instead of trying to falsify what's true and real, why not try to show that it's not without precedent as i've claimed.

im not moving the bar.. i am correcting the flaw in your argument..

catastrophic failure due to flutter is concerned with TAS, the actual speed air is passing the airframe.. NOT the amount (EAS/CAS)..

look at it this way..
the air passing the airframe when flying at 510knots EAS at 700 feet is 510knots..

but by saying that 510knots EAS is the same as 722knots TAS at 22000, although not wrong, when you are looking at the speed at which the air is passing the airframe, its 722knots.. but this is not the case.. flight 175 has air passing the airframe at around 510knots.. you saying its the same as air passing the airframe at 722knots is misleading.. you are using two different TAS speeds to support your argument, this is misleading, there is only one TAS speed you should have used when working out is flutter would have caused it to break apart...

to me it looks like you are deliberately doing it backwards in order to mislead people.

NewAgeMan
reply to post by choos

 

The Vmo/Mmo is still 360k/.86M and the Vd/Md is still 420K/.91M, and air density or the total amount of air passing over the airframe is greater near sea level than at altitude, which is why the plane can cruise at .86 Mach at 35,000 feet +

yes, and your premise is that flight 175 is 90knots over Vd.. Vd which is primarily based on (unless im gravely mistaken is) flutter speeds.. and flutter speeds which is primarily concerned with TAS..

so a M0.91 at 22000feet is 554Knots TAS.. from the articles i have posted TAS does not decrease with decreasing altitude.. so we know the flutter speed is beyond 554knots TAS for all altitude below 22000feet.. which is higher than the 510Knots that flight 175 was flying at..

It's not misleading in the least

A1NM TYPE CERTIFICATE DATA SHEET.

Airspeed Limits:
VD = 420 KCAS to 17,854 ft/.91M above 23,000 ft, linear variation between these points
VFC (Maximum speed for stability characteristics - en.wikipedia.org...) = 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

It's you who are misleading, as was/is dragonridr and S.O., in the biggest way]was/is dragonridr, and S.O., in the worst way..

Here is the calculator, let's learn how to use it, while plugging in all the appropriate variables (see various screenshots throughout the thread).

www.luizmonteiro.com...

There's nothing misleading about the data represented in the OP or throughout this thread, or in terms of the various V-G Diagrams or screenshots from the calculator.

The research and data is valid - the only question being if it's possible for an unmodified 767 to FLY in control, even tight control, without suffering any structural failure or loss of control when flying 90 knots over it's Vd design dive limit and 150 knots over it's Vmo. Furthermore the air is thicker (more air to fly though), and thus the 420 K Vd limit, harder, closer to sea level because it involves a higher overall dymamic pressure on the airframe than at altitude where the air is increasingly thinner.

No need to keep going around and around.

At least BenReclused made an attempt at a serious rebuttal when he talked about and ref'd the ULTIMATE design limit, although that was a load limit and not an airspeed limit, and doesn't mean or imply that Vd is then an "operational limit", plus it mentioned it as a limit that can be reached only for 3 seconds prior to immediate catastrophic failure, whereas "the plane" was travelling at close to that same airspeed, for well over a minute.

Milt's argument

www.abovetopsecret.com...

www.abovetopsecret.com...

Been away from this thread for a few days, came back, looked at the most recent stuff and have this to offer.

NAM has made - in his OP - a premise that some of us consider flawed.

Frankly, nothing short of water boarding him (and that probably isn't going to work either) will shift him from his position.

Similarly for those of us who consider the premise flawed, nothing short of water boarding (and that probably isn't going to work either) will shift us from our position.

The end result is a stalemate, a pointless waste of time. Its arguing for the sake of it and for the chance to repeatedly post the same information over and over and over and over and over and over and over and .....(you get my point)

There is no resolution here. I suggest a simple case of agreeing to differ.

reply to post by neformore


right.. well.. I have one question..

Has your mid ever been made up over things you've researched due to the amount of data you've discovered??

exactly.. so why trash a member so done an excellent job of researching the subject and presenting it as best they could with the tool they have..

slam it in the hoax bin and assassinate his character..

reply to post by Komodo


To answer your question. Yes, I have had my mind changed before by people using a combination of data, observations and logic. unfortunately for the OP, this isn't one of those cases, for the reasons I've outlined in my posts in the thread. To be clear on that, NAM has an opinion that the aircraft in question isn't capable of doing something. I don't believe that is the case.

To answer your point, I didn't move the thread.

And to respond to your premise, I haven't "trashed" anyone. I disagree with NAM's opinion about the issue. That's not "trashing" anyone, that's simply the way the world works.

reply to post by NewAgeMan


the data isnt misleading.. your interpretation of the data is misleading.. here is a quote from pg2:

NewAgeMan
...
UNMODIFIED commercial aircraft break apart due to "flutter" at around Mach 1.0 (which is achieved in a dive) or, an EAS of about 425 knots at sea level. It was all covered in the OP, in detail.

www.abovetopsecret.com...

now was this post in reply to phage posted by the same NewAgeMan as the current NewAgeMan??

if you did not post this then i guess i can leave and be on my merry way.. however if you did post this then you are being misleading, and probably trying to obfuscate the matter.. your pilot friends also should have known although perhaps maybe they didnt, regardless they have remained silent about this..

and that is:

There is, in fact, an altitude effect on flutter speed that is different from the altitude effects on the rest of the aerodynamics, but it is not as severe as many people say and think.� Many people apply a "constant true airspeed" rule that is much too severe, and can in itself create other safety problems (like unwillingness to fly fast enough to escape sink, to clear a high ridge, etc).

As you may know, most aerodynamic forces are scaled with the dynamic pressure, q = 1/2 (rho) V^2.� So as you go up in altitude and the density, rho, decreases, you compensate by adding more V^2 to get the same lift and drag.� It also turns out that the pressure that a pitot tube measures is the dynamic pressure, (Pt - Ps = q) , so indicated airspeed (ias) tracks dynamic pressure.� Conclusion:� Constant indicated airspeed means constant aerodynamic properties.� The same lift/per unit area for a given angle of attack.� The only minor deviation from this characteristic is the subtle effect of Reynolds number.

But flutter is different, because of the inertial coupling and the damping effect of the air.� So flutter speed does not remain a constant indicated airspeed as you increase altitude.� The flutter speed (expressed as an ias) decreases slowly as you increase altitude.� But nowhere near as fast as the indicated airspeed would decrease if you kept the true airspeed constant and increased altitude.

quest.arc.nasa.gov...

and

But flutter does not depend on Indicated Air Speed/dynamic pressure. It is directly related to True Airspeed - the velocity of the air passing by the air frame. The velocity of the excitation force is the prime concern, not the magnitude. It is very possible to exceed this critical "flutter speed" without encountering flutter if there is no initial disturbance. But if the critical flutter speed is exceeded and then a disturbance is encountered, the aircraft structure will bgin to oscillate in response to the velocity of the passing air.

www.vansaircraft.com...

first up, do you understand what these two documents are telling you?? it is telling you that flutter speed is based on TAS.. flutter speed depends on the speed which air passes the airframe.. flutter does not rely on dynamic pressure ie. EAS/CAS is irrelevant to flutter speeds.. TAS is what matters with flutter speed..

and above i have already shown you that from the TCDS the maximum permitted TAS is around 554Knots.. which is beyond the 510knots TAS the flight 175 was clocked at.

so your premise that 425knots EAS at sea level is the same as 425 knots EAS at 22000 feet means that the aircraft should breakup due to flutter is wrong and misleading.. this is what im correcting yes 425 knots EAS at sea level is the same as 425 knots EAS at 22000 feet, but that is irrelevant as phage has already stated, it is also misleading.. what matters is TAS when dealing with flutter.. and the fact is flight 175 was flying at around 510knots TAS at 700feet and not 722K TAS so critical failure due to flutter should not be a problem.

Due to the apparent refusal of this site's owner to address the validity of the flawed document, upon which his decision to move this thread to the "Hoax Bin" was based, I now realize that honesty, and sincerity, regarding that decision, are nothing more than "foreign objects".

Because of that, and with a great deal of disappointment, I will no longer be participating in this thread. It's been fun, and I'm "out of here"...

See ya,
Milt

choos
yes 425 knots EAS at sea level is the same as 425 knots EAS at 22000 feet, but that is irrelevant

Sorry you've misunderstood, that's not so, because near sea level, EAS, and TAS are nearly the same, whereas, if the airspeed near sea level is evaluated in terms of the difference in dynamic pressure between low vs. high altitude, at 22,000 feet that same speed amounts to a TAS of 722 knots or 1.19 Mach and higher, at higher altitudes as the air becomes increasingly thinner.

Furthermore, an EAS of 425 knots, near sea level, represents a TAS, at 22,000 feet, of .99 mach which IS the point at which the out-of-control Egypt Air 990 (see V-G Diagram) experienced structural failure.

The statement at the beginning of post 2 is entirely valid.

It is you who've tried to confuse the issue, and mislead, not i.


To further clarify re: excessive speed..

New York Times
February 23, 2002
A NATION CHALLENGED: THE TRADE CENTER CRASHES; First Tower to Fall Was Hit At Higher Speed, Study Finds
By ERIC LIPTON AND JAMES GLANZ

Researchers trying to explain why the World Trade Center's south tower fell first, though struck second, are focusing on new calculations showing that the passenger jet that hit the south tower had been flying as fast as 586 miles an hour, about 100 miles an hour faster than the other hijacked plane.

The speed of the two planes at impact has been painstakingly estimated using a mix of video, radar and even the recorded sounds of the planes passing overhead.

Two sets of estimates, by government and private scientists, have surfaced, but both show that the plane that hit the south tower at 9:02 a.m., United Airlines Flight 175, approached the trade center at extremely high speed, much faster than American Airlines Flight 11, which hit the north tower at 8:46 a.m.

In fact, the United plane was moving so fast that it was at risk of breaking up in midair as it made a final turn toward the south tower, traveling at a speed far exceeding the 767-200 design limit for that altitude, a Boeing official said.

''These guys exceeded even the emergency dive speed,'' said Liz Verdier, a Boeing spokeswoman. ''It's off the chart''.

And indeed it was..

V-G Diagram.

reply to post by neformore


From what you are saying, I take it then, that you are in agreement with S.O. - as to the premise and the reasoning and justification behind his decision to edit the title, and the OP, with that "ADMIN NOTICE:" and then proceed to move the thread to the hoax bin.. on that basis?

If so, I advise you to read my rebuttal/objection and the subsequent posts by the member BenReclused, who wished to debate the premise of the OP and thread content, based on an entirely honest assessment of the facts.

No fraud, no "hoax" and no falsification of the data presented in the OP was committed by me, or the Pilots and Aeronautical Engineers who's research I accessed in authoring the OP.

And although it was intended in jest, i find your reference, twice, to "water boarding" to be .... never mind (T&C).

reply to post by BenReclused


No, wait, Milt, you old friendly troll - come back! My opinion of you changed (improved) when you started standing up for what was obviously true (the data, not necessarily the interpretations). My opinion of ATS however is at an all time low. I think this subject (911) is better suited to sites where the owners support questioning of the OS.