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

reply to post by charlyv


That was just a factoid in response to Phage, as VMO/MMO, which simply means the difference between a speed expressed in knots vs. Mach #, as the operating speed limit - was not, in case you didn't notice, the basis of the OP, which is one of EAS relative to the Vd structural limit based on wind tunnel and in-flight "flutter" testing, by which that limit (of 420 knots, EAS) is set.

And to grasp the nature of that airspeed (420 knots EAS), which doesn't sound like much, but it's just five knots below the equivalent airspeed, at low altitude, of .99-1.0 Mach at just 22,000 feet, and obviously higher the higher you go as the air thins.

Boeing commercial airliners simply cannot go much faster than their Vd limit, even in a dive (a speed which typically can only be reached in a dive), without being at risk of breaking apart, and 420 knots is 90-95 knots "slower" than the south tower plane was clocked at, where at 425 knots EAS we're at the equivalent airspeed threshold of Mach 1, at altitude.

I hope everyone "gets" this, because it's elementary and unequivocal.

reply to post by NewAgeMan

That was just a factoid in response to Phage, as VMO/MMO, which simply means the difference between a speed expressed in knots vs. Mach #, as the operating speed limit

No, that is not right. Phage is a stickler for definition, and so am I.
Irregardless of your main point, this statement is not correct. We know that each one is expressed in Knots, and in Mach.... however they are not "simply the difference between a speed expressed in knots vs Mach.

VMO is safe margin as determined by various wind speed/gust upset/recovery tests and also covers parts of the aircraft that have a much lower tolerance for wind speed.

MMO is save margin as determined by the effects of approaching Mach. Vibration, Flutter, Nodal relationship problems, metals that distort at differing frequencies.....

In each, the lowest tollerance critical part sets the numbers for the aircraft.

reply to post by charlyv


Fair enough, because MMO is the factor for higher altitude exceeding 25,000 feet where Mach # is applicable, and of course there are transonic effects as Mach 1 is approached, at altitude, where the flutter tests, as per the Airbus example cited in the OP typically stay within a range of .96 Mach, but that's not the MMO, but the Vd limit where MMO is something like 90% of Vd, which is the structural limit set first by wind tunnel and then by flight testing.


However, in terms of EAS (equivalent airspeed, at low altitude), to get an idea of just how far past the Vd limit of 420 knots for the Boeing 767 the south tower plane was flying

an EAS of 510 knots = 722 knots or Mach 1.19, at 22,000 feet, and at still higher altitude, 915 knots or Mach 1.38, at 35,000 feet, and reaching Mach 1.39 at about 38,000 ft.

www.luizmonteiro.com...

There is no precedent of any Commercial Airliner, except the Concorde, reaching such airspeed at any altitude, and surviving.

Furthermore, there is no denying that the plane exceeded it's Vd limit by NINETY knots, and it's VMO by 150 knots.


P.S. You say that Phage is a stickler for detail and definition, but he thought that the MMO of .86 Mach applied equally, at all altitudes. And if we're going to be sticklers, there's no such word as "irregardless".

Helious

NavyDoc

Asktheanimals
reply to post by spooky24

 

You can prove that these calls were made from the very airplanes that crashed in to the towers/pentagon/shanksville?

Where are the black boxes and cockpit voice recorders?
Why don't 2 of them have serial numbers ascribed to them in the reports?
How could they lose all of the black boxes from the planes that crashed in to the towers when every last single piece of debris was gone over several times both on site and at Fresh kills?
Maybe they didn't find them because they weren't the supposed passenger flights?

Calls from above 20,000 feet were proven impossible to make.
Can you prove the voices on the calls were authentic?

Novice pilots flying 767's like they supposedly did on 9/11 would be like any of us jumping in an Indy racer and making course speed records in the process.
Ain't gonna happen.

You can make calls above 20,000 feet. Where was it proven you could not? You can make a call 4 miles from a cell tower on land, what does altitude have to do with it?

Because cell towers in 2001 broadcasted signals horizontally not vertically and while there is some spillage in the vertical, the cell phone calls made above about 5 thousand feet have been shown without a doubt to me mathematically impossible.

Don't take my word for it though, if you have the time and attention span, try reading this for some detailed, factual insight into the matter, if you get through it all as I have, you will change your opinion of calls being made at 20k feet from cell phones. The government did.

Check it out

edit on 30-12-2013 by Helious because: (no reason given)

You use a conspiracy blog as "proof?" C'mon. I've used a cellphone as early as the late 1990's over 30,000 feet. Radio waves are much more omnidirectional than you think. Although cellphone towers are built to push the energy of the signal laterally, to overcome obstacles such as walls and hills, much less energy is needed to go up, where there are no obstructions. You don't get a sideways signal with "a little bleed-over" you get a parabola.

The statement was that the call could not have come from flight 93 because it is "impossible" for cell phone signals to reach from above 20k feet. That statement is patently false.

Star and Flag New Age. As for some of the users questioning the thread.


Bush Addresses the U.N. - tells the world no 911 discussions


Bush says Bin Laden and his terrorists did it. Therefore we can not tolerate any outrages 911 discussions. I am sure some of us remembers this speech.

NavyDoc

Helious

NavyDoc

Asktheanimals
reply to post by spooky24

 

You can prove that these calls were made from the very airplanes that crashed in to the towers/pentagon/shanksville?

Where are the black boxes and cockpit voice recorders?
Why don't 2 of them have serial numbers ascribed to them in the reports?
How could they lose all of the black boxes from the planes that crashed in to the towers when every last single piece of debris was gone over several times both on site and at Fresh kills?
Maybe they didn't find them because they weren't the supposed passenger flights?

Calls from above 20,000 feet were proven impossible to make.
Can you prove the voices on the calls were authentic?

Novice pilots flying 767's like they supposedly did on 9/11 would be like any of us jumping in an Indy racer and making course speed records in the process.
Ain't gonna happen.

You can make calls above 20,000 feet. Where was it proven you could not? You can make a call 4 miles from a cell tower on land, what does altitude have to do with it?

Because cell towers in 2001 broadcasted signals horizontally not vertically and while there is some spillage in the vertical, the cell phone calls made above about 5 thousand feet have been shown without a doubt to me mathematically impossible.

Don't take my word for it though, if you have the time and attention span, try reading this for some detailed, factual insight into the matter, if you get through it all as I have, you will change your opinion of calls being made at 20k feet from cell phones. The government did.

Check it out

edit on 30-12-2013 by Helious because: (no reason given)

You use a conspiracy blog as "proof?" C'mon. I've used a cellphone as early as the late 1990's over 30,000 feet. Radio waves are much more omnidirectional than you think. Although cellphone towers are built to push the energy of the signal laterally, to overcome obstacles such as walls and hills, much less energy is needed to go up, where there are no obstructions. You don't get a sideways signal with "a little bleed-over" you get a parabola.

The statement was that the call could not have come from flight 93 because it is "impossible" for cell phone signals to reach from above 20k feet. That statement is patently false.

Conspiracy blog? Try reading all of the facts, the cold hard facts regarding the matter on the link I offered, if you question any of the points that are made or contest the validity of anything said, I would be more than happy to show you specifically why you're wrong. All of the evidence used to deduce facts in the article provided are backed up in spectacular detail by source material, all nicely labeled and indexed, every single point.

The government itself even acknowledges the fact that all calls made above around 5,000 feet were made by "air-phone". Do you know why that is? Of course you don't because instead of seeking out truth or facts, you would rather speculate and promote juvenile conjecture and accuse anyone not as ignorant of the facts as you a "conspiracy theorist".

You couldn't make calls that math and logic agree with in 2001, period. But that really isn't a conspiracy theory is it, since the government itself says now that those calls above 5k feet were made by air phone not cell phone even though initial reports were cell phone. I know why they changed the narrative, do you?

reply to post by NewAgeMan


Air Force One Type Jet Footage over New York April 27th 2009

www.youtube.com...

Evidence . Unless those 19 alleged terrorists are super pilots.

Brilliant thread !
My belief has always been the planes were remotely controlled.
As others have said.....How and why would inexperienced pilots fly the planes in such a manner and at the speeds they flew ?
Those planes were definitely military drones IMO....
What happened to the passengers and the original planes....only God knows.

Great work NAM !

Yet again you have answered all your knockers and sent them packing.

Agent_USA_Supporter

Bush Addresses the U.N. - tells the world no 911 discussions

Bush says Bin Laden and his terrorists did it. Therefore we can not tolerate any outrages 911 discussions. I am sure some of us remembers this speech.

Drawing on the writings of Philip D. Zelikow, future Chairman of the 9/11 Commission Whitewash/Cover-up, combined with the evidence in this thread, including the self evident nature of the CD of the twin towers (and building 7) - I have some thoughts as to the real reason that Bush made that statement at the UN, as well as the nature of the magnitude of the evil genius of the planning of such an "op", involving a type of conspiracy theory as to their use of the much maligned term (post JFK assassination) - "conspiracy theory" - that arise, as we play the tape all the way back through 9/11 "history" (including the "war on terror") to the "formative event" itself, and then looking through it to it's formative policy in Zelikow's 1998 think tank publication, "Catastrophic Terrorism: Elements of a National Policy" the recommendation of which found it's way into the Dick Cheney led PNAC (Project for a New American Century) think tank's policy document, "Rebuilding America's Defences, Strategy, Forces and Resources For a New Century", but that's another thread topic. In a nutshell it involves an extremely cunning use or hijacking of Occam's Razor, combined with an idiom called "the honey pot"

"A honey pot, in intelligence jargon, is a tempting source of information or 'dangle' that is set out to lure intended victims into a trap. Ultimately the honey pot is violently and maliciously discredited so as to destroy the credibility of anything stuck to it by association." (Michael Ruppert, "Crossing the Rubicon," p. 184)

into which the anticipated "outrageous conspiracy theories" would go, with the OS "narrative" serving as the only "believable" explanatory hypothesis which may be considered by the general public and shared with "the relevant political community" to be "consistent" with all known "facts" and phenomenon "believed or thought to be true, although no necessarily true" even in the event that some of them "might not even adhere to the laws of physics" (Zelikow's actually said that too).

In this way ATS may be considered a type of "honey pot" even without a knowing and self-aware, malicious or malevolent intent on the part of the site ownership and/or it's mods, simply because of the very word "conspiracy" and "conspiracy theory", although I'll give it to them that they called this forum "9/11 Conspiracies" and not "9/11 Conspiracy Theories" although it's ripe with some outlandish things, some credible, like this thread's content. some not so credible (like no plane theories as but one example) although by association alone, this information may be subject to ridicule and maliciously discredited, as we've already seen in this very thread. Even the use of the word "truther" (said with snarling contempt), or, as a group, the "9/11 Truth Movement" is a prime example, even though all it is, really, is the movement of the truth that the official story about 9/11 cannot be believed and must be considered nothing but a murderous hoax and a Big Lie of the very worst kind.

"The Big Lie"

All this was inspired by the principle - which is quite true in itself - that in the big lie there is always a certain force of credibility; because the broad masses of a nation are always more easily corrupted in the deeper strata of their emotional nature than consciously or voluntarily; and thus in the primitive simplicity of their minds they more readily fall victims to the big lie than the small lie, since they themselves often tell small lies in little matters but would be ashamed to resort to large-scale falsehoods. It would never come into their heads to fabricate colossal untruths, and they would not believe that others could have the impudence to distort the truth so infamously. Even though the facts which prove this to be so may be brought clearly to their minds, they will still doubt and waver and will continue to think that there may be some other explanation. For the grossly impudent lie always leaves traces behind it, even after it has been nailed down, a fact which is known to all expert liars in this world and to all who conspire together in the art of lying.

~ Adolf Hitler, "Mein Kampf"

reply to post by totallackey


Please keep this crucial info out of Skunks Works Category.

27th April 2008 and 2009 same date. Check out the Washington Govt stage managed fly-bys of AF1 and also with the defunct space shuttle piggy back flight - Ritual ?. Well done OP !

reply to post by charlyv

No, that is not right. Phage is a stickler for definition, and so am I.

And yet, you make this follow up paragraph containing the initial word...

Irregardless ...

Whatever...

reply to post by totallackey

Funny, sort of, but I can't give you a star for that because we've got bigger fish to fry here.

What's strange is there's been no stampede of debunkers using the word "truther" in a derogatory manner, and no disinfo whether knowingly or unwittingly ie: no "no planer" replies, no DEW weapons theories, no "the hijackers were fake" (they were a much needed component for the official narrative about what happened) etc. and very little if hardly any vitriolic oratory by the "truther" haters.. !

Well done ATS, I'm impressed with you in terms of how this information was received, whether you "agree" with it or not, although there's no disputing certain facts in evidence here. Even if you believe that the plane can fly at that kind of airspeed, understood in terms of EAS, Vd, and their implications as outlined in painstaking detail time and again in this thread, without falling apart, one can hardly imagine Marwan al-Shehhi, on par in terms of flight training and "skill" level, with that of Hani Hanjour, piloting that aircraft.

Experienced pilots with 1000's of hours in the UA flight simulator tried again and again, with the crash logic of the simulator disabled (to make it possible) to re-create the turning dive and target acquisition (of the Tower) and were unable to do it, until slowing to near landing speed. It's like driving through a garage, with the south tower hit at the lower level (as planned..), the plane at the end of banking turn capable of dropping the nose and thus pulling G's, with the right wing bending slightly.


Flight Control

Alleged Hijackers
The team of hijackers on United Airlines Flight 175 was led by Marwan al-Shehhi (alleged flight 175 "pilot"), from the United Arab Emirates. Shehhi obtained a commercial pilot's license while training in south Florida, along with Flight 11 hijacker and plot coordinator, Mohamed Atta. The muscle hijackers on Flight 175 included Fayez Banihammad, from the UAE, and three Saudis: brothers Hamza al-Ghamdi and Ahmed al-Ghamdi, as well as Mohand al-Shehri. On August 13, 2001, Marwan al-Shehhi purchased two four-inch pocket knives from a Sports Authority store in Boynton Beach, Florida, while Banihammad bought a two-piece snap knife set at a Wal-Mart, and Hamza al-Ghamdi bought a Leatherman Wave multi-tool.

In early September 2001, the Flight 175 group of hijackers arrived in Boston from Florida. Hamza al-Ghamdi and Ahmed al-Ghamdi arrived together on September 7 and checked into the Charles Hotel in Cambridge, Massachusetts. The next day, they relocated to the Days Inn in Boston. Fayez Banihammad flew from Florida to Boston, along with Mohand al-Shehri, on September 8, and they checked into the Milner Hotel in Boston. Marwan al-Shehhi arrived in Boston on September 9 and stayed at the Milner Hotel, where he shared a room with Mohamed Atta.

United Airlines Flight 175
en.wikipedia.org...

As to the hijackers, I think i'll do a quick bio on Marwan al-Shehhi and Hani Hanjour, of which the 9/11 considered Hanjour to be slightly better "trained" as a would be "heavy" pilot. We'll come back to that, and that passport, the indestructible passport, which wasn't found in the rubble but a number of blocks away, so it might be a good idea to pin down that location while determining the precise windspeed and direction that day, because as we all know a passport is rather a little more "weighty" than a piece of paper and can only "flutter" or fly so far, a line of investigative inquiry yet to be pursued... (go to it if anyone would like to take that one on), it would be interesting to know if it could have fluttered to that location, presuming of course that it could escape the impact and fireball and destruction, unscathed in the first place, but let's give them the benefit of the doubt and see if it's in the realm of conceivable that it could have traveled such a distance in the very light wind to the N/W.

"There is nothing now hidden which will not be made known and brought to light."

So, for those who will - Please feel free, instead of merely mocking each other over our different viewpoints, to simply share this thread and information with all the tools available (see upper right of your screen) and offered freely here at ATS to maximize our impact on the "noosphere".

Or use the thread title OP's url,
www.abovetopsecret.com...

send it out, on an email blast if you like, people need to see and consider this information. If you have a bias against it, fine, don't even bother reading further if you don't want to, but for whoever has found this info relevant and important, for the love of God and people share this thread with the world, you can do it, and so can everyone you point it to (hello, thanks for coming). This is the new reality which Mr. Philip Zelikow never contended with in hatching the evil policy in the first place, a historical tipping point (when the Big Lie's back is broken, it's power to mold or shape anything of value rendered null) that he did not anticipate, even and especially as the "experiencing generation begins to pass off the scene".
It's the elephant in the room that isn't going away and cannot and ought not be forgotten, given the degree to which it "changed the world" and it wasn't for the better.

The psy-op, the info war for our minds, can stop right here and now as we recapture that pre-9/11 innocence before the monstrous deed took place (but not without an appropriate remembrance and awareness and knowledge of), an event which need not have happened, and neither need happen what's happened in it's wake all the way to our current loss of privacy and civil liberty amid the militarization of the bureaucracy and all manner of covert and OVERT abuses of power, all in the name of our "security" and the war on terror which by now has almost managed to become a self fulfilling prophecy, to perpetuate it.

That's what they planned for a state of perpetual warfare, and we are absolutely EXHAUSTED, we can't take this crap any more, so the truth at the very heart of the matter as the first cause and the ever present and never forgotten elephant in the room - must have an opportunity to see the light of day and we have, right here before us, the medium right here at our very fingertips. Use it, today if it's in your power and your interest to do so. Who would have known..

May God once again bless the United States of America. We the world LOVES YOU. We have a love affair with you and your image, or at least we did until you or your government I should say, became a raving bully, but it started with this abominable policy that victimized the whole world. It was bad policy.
Nothing but a mad power grab and a couple of needless and unjustified wars of "pre-emption" in the name of security for the Crime of the Century and perhaps the most monstrous and the most heinous and barbaric of acts, the false flag, black-op, psy-op. Eisenhower warned us..

Best Regards,

NAM aka Winston Smith.

*negative sound, approximated by "ehh!*

1. The speed of the aircraft that hit the WTC was officially reported as between 500mph and 560mph ground speed, calculated by the observed point to point distance covered over time.
2. A Boeing 767-200 airframe is rated to .86 of Mach speed (speed of sound) at any altitude before the risk of structural failure. It as the aircraft approaches the speed of sound when the properties extreme high and low pressure areas can have destructive effects on the airframe. This figure is as with all limits set conservatively.
3. The speed of sound at approximate sea level is 761 mph on a standard day. Therefore the theoretical maximum speed the 767-200 can reach intact is, conservatively, .86 x 761mph = 654mph or approximately 100mph above the officially reported speed of AA11 or UA175.
4. The 767-200 is an aircraft that’s considered highly powered due to its requirement to function with only one engine for ETOPS - Extended-range Twin-engine Operational Performance Standards. It is capable of taking off fully loaded with only one engine.
5. The 767-200 is considered by pilots and aviation professionals to be a “slick” or “low drag” aircraft, being without bulbous construction and with highly swept 31.5 degree wings. It is well known that it is difficult to keep the 767 aircraft from over-speeding during decent; due to its low drag/high power configuration.


next...

NewAgeMan
Btw, once groundspeed is known (see radar data in post 2), to calculate airspeed, the windspeed vector would be added, which, as a light wind to the N/W would in this case increase the plane's airspeed slightly, to about 515 knots - at about 700 ft. alt. so it was over the Vd limit of 420 knots,
by about 95 knots.

edit on 30-12-2013 by NewAgeMan because: (no reason given)

this V-G diagram is very misleading.. its been photoshopped at least once..

i ask because it seems extremely simplified and misleading..

wheres the mach number?? and wheres the altitude limits??

a Vd limit of 420 knots is very misleading, since we dont know at what altitude that is for.

reply to post by bbracken677


Oh...and what is the ground speed of an unladen swallow?

reply to post by bbracken677


African or Europeon?

InTheFlesh1980
reply to post by Phage

 

Phage, I really respect your scientific approach on a lot of topics. You truly are a highly intelligent individual.

But regarding specific topics, like this, your thickness is brutally evident. You are sorely lacking in the ability to evaluate probability. There are countless topics you have commented on which you entirely lack proof of your assertions, citing arguably biased sources, claiming to be a pure "scientist".

Part of being a scientist is understanding when the basis for your postulations is fraudulent (i.e. "not YOUR research", the research of those with an AGENDA). You lack this, and thus you lack true objectivity.

The official story regarding 9/11 is a mathematical impossibility. Period. There is no model of probability which can support it. Yet you perpetually interject your complete improbabilities as if they hold merit.

I will not argue the details, as they rest on the deafest of ears. Let it be known, your words here have no more merit than the next. And although you may have a wonderful grasp of the austerity of scientific methods, you are wanting much in the ability to draw conclusions from the most obvious body of evidence in conspiratorial history.

Lots of posts and stars about planets mean nothing to me, or to many others around here.

Cheers and Happy New Year! Having dinner with Al Gore?

Best post ever!

bbracken677
*negative sound, approximated by "ehh!*

1. The speed of the aircraft that hit the WTC was officially reported as between 500mph and 560mph ground speed, calculated by the observed point to point distance covered over time.

False. The 9/11 Commission Report pegged the speed at 510 knots, as did/does the NTSB Radar Data.

Flight 175 crashed into the southern facade of South Tower of the World Trade Center (Tower 2) at 9:03:02, traveling at approximately 590 mph (950 km/h, 264 m/s, or 513 knots)
National Transportation and Safety Board (February 7, 2002). "Radar Data Impact Speed Study" (PDF). NTSB. p. 2. Retrieved 2010-12-29.
en.wikipedia.org...

The plane was clocked travelling at 510 knots or about 585-590MPH.

2. A Boeing 767-200 airframe is rated to .86 of Mach speed (speed of sound) at any altitude before the risk of structural failure. It as the aircraft approaches the speed of sound when the properties extreme high and low pressure areas can have destructive effects on the airframe. This figure is as with all limits set conservatively.

False. Firstly, it's a true limitation based on wind tunnel and flutter testing because it's essential to know the limit beyond which structural failure becomes imminent, for certification, set initially from wind tunnel flutter testing, and then proven in a flight test and if too high either adjusted lower or compensated via re-design and modification (see the Airbus example in the OP as to how this process takes place). The VMO/MMO is the only real limitation that the pilot is truly aware of, although he/she understands that it's a certain percentage of the Vd structural limit.

Secondly, the MMO of Mach .86, is the operational speed limit (as distinguished from Vd, expressed in EAS to factor equivalent airspeed at low vs. high altitude in terms of the dynamic pressures on the airframe), at 35,000 feet, where cruising speed at that altitude is Mach .80, a range which is doable because the air is thinner, over 2/3rds thinner at that altitude vs. near sea level where conversely the air is 2/3rds thicker. Thus, as an expression of Mach #, the MMO decreases with altitude whereby at 23,000 feet, the corresponding VMO of 360 knots is reached, which as an EAS (equivalent airspeed) is equal to Mach .86 at you guessed it, 23,000 feet (see calculation and examples in the screenshot below).




VMO/MMO = maximum operating limit speed is a speed that may not be deliberately exceeded in any regime of flight (climb, cruise, or descent)

Question: Why are there two speeds, i.e VMO-slash-MMO
Answer: VMO/MMO refers to "Airspeed or Mach Number", whichever is critical at a particular altitude (Remark: Mach no. is usually not calculated below 25,000 ft)

VMO is based on the IAS (indicated airspeed), which is simply speaking measuring the plane's aerodynamic drag.

This aerodynamic drag gets lower in thinner air = on higher altitudes.

A constant indicated airspeed results in a higher Mach number and a higher True Air Speed=TAS, the higher a plane flies.

Examples:

_Alt MSL_IAS__TAS__mph__Mach
___500ft 290kt 290kt 334 0.44
_1,000ft 290kt 296kt 340 0.45
10,000ft 290kt 348kt 400 0.54
25,000ft 290kt 435kt 501 0.72
35,000ft 290kt 493kt 567 0.86 = speed limit

3. The speed of sound at approximate sea level is 761 mph on a standard day. Therefore the theoretical maximum speed the 767-200 can reach intact is, conservatively, .86 x 761mph = 654mph or approximately 100mph above the officially reported speed of AA11 or UA175.

False. See examples, and explanation above. It just doesn't work that way. Because of aerodynamic pressures at low vs. high altitude, so too is the VMO reduced, with the dive speed limit of 420 knots representing the Vd structural limit, which to understand in terms of equivalent airspeed, only stacks up to the MMO of Mach .86 when the plane reaches it's VMO at an EAS of 360 knots near sea level or Mach .86 at 23,000 feet to 35000 feet.

4. The 767-200 is an aircraft that’s considered highly powered due to its requirement to function with only one engine for ETOPS - Extended-range Twin-engine Operational Performance Standards. It is capable of taking off fully loaded with only one engine.

That may be so. Sounds legit.

5. The 767-200 is considered by pilots and aviation professionals to be a “slick” or “low drag” aircraft, being without bulbous construction and with highly swept 31.5 degree wings. It is well known that it is difficult to keep the 767 aircraft from over-speeding during decent; due to its low drag/high power configuration.

That may be so. Sounds legit. Always good to throw in a couple of facts that cannot be denied to bolster the other statements and appear really knowledgeable, but it can't alter the truth or the reality of what we're really looking at here.

next...

next...

reply to post by choos

choos

this V-G diagram is very misleading.. its been photoshopped at least once..

as I already stated earlier

NewAgeMan

Btw, the graph used is not "fake" but perfectly represent the facts, found here

rgl.faa.gov...

Just go to the "TCDS" Type Certificate Data Sheet Information PDF on the left side when you get there.

But here's some more to ease your mind


The VG Diagram Explained (posted earlier)
Many manufacturers do not include aircraft VG diagrams in their aircraft flight manuals due to the fact you can plot your own if the limitations are known. The VG diagram we plotted is not "fake" nor "manipulated". It represents the limitations of the Boeing 767 according to the Boeing Type Certificate Data Sheet including weights and altitude. A typical VG diagram was used with the 767 limitations inserted into their respective positions in the diagram. It is an accurate depiction of the relevant Boeing 767 limitations for the purpose of research.

Original/typical VG Diagram
www.free-online-private-pilot-ground-school.com...
(scroll down to Figure 4)

V-G Diagram Discussion with APS Training
apstraining.com...

VG Diagram depicting Boeing 767 Limitations using typical VG Diagram
s47.photobucket.com...

Boeing 767 Diagram created using VG Diagram from Illustrated Guide To Aerodynamics

VMO Maximum operating limit speed
VNO Maximum structural cruising speed or maximum speed for normal operations.
VD Design diving speed
VNE Never exceed speed

Both Vd and Vne are used as the end of the flight envelope and the start of the structural failure zone.

Example

Example

The above is for a 767, reduce the speeds by 10 knots for a 757.

The speeds are based on the weight ranges in the A1NM Type Certificate data sheet
rgl.faa.gov...$FILE/A1NM%20Rev%2026.pdf
which also gives an altitude range.

The above diagram is good from sea level, up to almost 18,000 feet. Above that, the Vg diagram moves to the left. In other words, structural failure speeds are less in terms of Indicated at higher altitudes. Real pilots can see this as they climb. The Vmo indicator (Barber pole) actually moves to a lower airspeed once you climb above the crossover altitude. The reason for this is the aircraft is no longer limited by raw dynamic pressure, rather it is now becoming limited by the effects of Mach (both drag related, which is why EAS is calculated using Mach number and good to above Mach 2).

bbracken677

A Boeing 767-200 airframe is rated to .86 of Mach speed (speed of sound) at any altitude before the risk of structural failure.

And according to you bbracken677, various govt loyalists, shills, debunkers, troofer haters and ah.. heavily laden American swallows.. this is where an aircraft can allegedly operate while maintaining flight control.