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

reply to post by MarioOnTheFly


See you keep saying untrained i know for one Atta wasnt he received a commercial pilots license.He ateended dozens of flight schools and was capable of flying a passenger liner.His job was made easier by noy having to worry about take offs or landings though with his training i believe he would have been just fine and muddled through.He learned enough about aircraft to turn off the transponder and set courses then to turn off autopilot when he got there thats all he needed to know.

soulwaxer
No, I am talking about the "master muslims" who would have planned this, from their secure position in a cave... You know, like Osama Bin Laden, and all his religious extremist brothers still in the homeland. The ones that have been hunted down ever since. In OBL's case, he even got fake-buried in the sea. Or do you think he had balls of steel, endless confidence, Allah behind him all the way...? He just KNEW that he could pull off this little feat and so he just went for it, from his cave?

Yes. Although not from a cave (really? you really have that view of people elsewhere?). He had a cause that he believed in. He lived out his cause. He managed, using a clever mix of money, religious fervour and politics to persuade people to carry out what he wanted to happen. Such methods have been used by manipulative people since the dawn of civilisation.

You apparently prefer to believe that the US government was complicit in the murder of over 3,000 people on the day, flew three airliners into buildings and one into the ground/shot one down, destroyed a whole building complex in the heart of NYC and then went on to cause the subsequent casualties and devastation in Afghanistan and Iraq (casualties conservatively estimated around 150,000 people) and pissed a whole load of people globally off in the process on purpose for....what benefit exactly? To further its own demise by pissing its own people off?

To coin a phrase - Listen to yourself, because it really is disturbing

reply to post by soulwaxer

Yes, remote controlled military drones. Why is it easier for you to believe that 19 men flew fully loaded jets square into the heart of the US, into oblivion, from a cave?

Well, first, I don't underestimate my enemy. Wars are lost that way and this one may still be lost by that approach. The war started that day is still not over and men still die in a far off land from those events.

Timeline of the Hijackers

Hijacker Timeline #2 ( Source)

The above documents lay out in great detail who each Hijacker was as an individual for their activities and documents. What ID they had, how they got it, when they got it and what, if anything, was recovered Post-Crash for each. It also goes into detail about each individuals travel habits into and out of the United States before the attacks. There is a lot of detail and it's educational for those who haven't read the data from years ago.

The leader of the nineteen was Mohamed Atta, and they were divided into four groups, one for each plane, each with a pilot who served as group leader: Atta, Marwan al-Shehhi, Ziad Samir Jarrah, and Hani Hanjour. Atta, al-Shehhi, and Jarrah had moved to Germany in the nineties to attend separate colleges [H1 ]and met through radical Muslim circles in Hamburg around 1998.

The Hijackers;
Who were they?

As the above indicates and other accounts detail much better, the Hijackers were not ignorant street fighters, scooped up to go kill some Infidels. They chose skilled and educated people among them so they could have their plan WORK..and not end in pathetic failure like 1993 (Where one of the morons actually went BACK to demand his rental truck deposit be refunded after the bombing).

In terms of Usama Bin Laden himself? He held University degrees in both Civil Engineering and Public Administration courtesy of Saudi Arabian Universities. As it happened, probably the two most useful degrees he could have asked for, for what he eventually became and had done in his name.

Wrabbit2000

The passport survived because it was blown away from the building.

Hi Wrabbit2000,

Could you indicate precisely where the passport was discovered, maybe with a NYC map graphic to pinpoint it's proximity to the North Tower? Thanks.

The wind was very light that day, to the N/W, as can be seen by the drifting smoke cloud from the North Tower, so if it managed to survive the firey crash and escape the building, unscathed, even in pristine condition, I'm curious as to the probably that it "blew" as far as it did given that a passport is a little weightier than a mere piece of paper. It's my understanding that it was found blocks away from the North Tower, but it would be nice to put it into the appropriate contextual framework in terms of probability.

Thanks again.

This is a little piece of research that i've just never had the time to adequately investigate.

Regards,

NAM

reply to post by NewAgeMan


I appreciate your curiosity. It is why I posted the complete trial record and evidence record from the 9/11 Murder Trial that item became a piece of evidence in.

I don't do people's homework for them. Certainly not on this one. I gave you exactly where you'll find it though. Somewhere in that testimony will be reference to that specific exhibit, how it was found, where it was found and the method it's been cataloged and handled since it was found.

I'm personally satisfied by the work of the New York City Police Dept in basic evidence collection for what was scattered across the streets around what used to be buildings. If you're not satisfied with the basic evidence collection though, I'd be quite interested to see what you find to disprove that evidence as valid, as it was accepted by BOTH Defense and Prosecutors for that case.

Particularly given the ease with which this should be possible, having the complete record addressing every aspect of evidence.

reply to post by Wrabbit2000


Vessey Street....93 also had two passports survive but you don't hear about those and that was supposedly a nose dive right?

Ziad Jarrah and Saeed al-Ghamdi

Wrabbit2000

I don't do people's homework for them. Certainly not on this one. I gave you exactly where you'll find it though. Somewhere in that testimony will be reference to that specific exhibit, how it was found, where it was found and the method it's been cataloged and handled since it was found.

Certainly not on that one, no, I didn't think so..

Anyway, I searched from the link you provided, and this is the only thing I could find. There's nothing else there about how it was found, where it was found, or the the method it's been cataloged and handled since it was found. Nothing, nada, zip. Just this.

www.vaed.uscourts.gov...

So I'll research this in terms of where it was discovered, and the proximity of it's location relative to the North Tower to try to determine the probability that it "blew" a certain distance, bearing in mind the height of the building from the impact area, light wind and wind direction.

Of course we do need to research these things ourselves, because more often than not there's no historical record, not even an official one to reply upon, as is the case here in regards to Satam's flying passport.

Here's what's in wikipedia, not that it's the most reliable or accurate source of information

Suqami's passport was found by a passerby (identity unknown), reportedly in the vicinity of Vesey Street,[8] before the towers collapsed.[9] (This was mistakenly reported by many news outlets to be Mohamed Atta's passport.)[citation needed][10] A columnist for the British newspaper The Guardian expressed incredulity about the authenticity of this report,[11] questioning whether a paper passport could survive the inferno unsinged when the plane's black boxes were never found. According to testimony before the 9/11 Commission by lead counsel Susan Ginsburg, his passport had been "manipulated in a fraudulent manner in ways that have been associated with al Qaeda."[9] Passports belonging to Ziad Jarrah and Saeed al-Ghamdi were found at the crash site of United Airlines Flight 93 as well as an airphone.[12]

en.wikipedia.org...

I'll try to come back with a map graphic, showing the North Tower and an x for the passport, along with the alleged distance traveled, blowing in the wind. If anyone would like to help with this, please feel free.

matafuchs
reply to post by Wrabbit2000

 

Vessey Street....93 also had two passports survive but you don't hear about those and that was supposedly a nose dive right?

Ziad Jarrah and Saeed al-Ghamdi

Flight 93 crash site

I just came across this in the process of looking into the other passport. Holy smokes!

Al Ghamdi's Passport
www.vaed.uscourts.gov...

Ziad Jarrah's Passport (at least his was burned, thank heaven..)
www.vaed.uscourts.gov...

And let's not forget this one either..

Red bandana recovered from the United Airlines Flight 93 crash site ...

Yes, "The Indestructible Red Bandana" video was overdramatized, but it makes the point.

double post..

SkepticOverlord
reply to post by MarioOnTheFly

 

As I pointed out previously, I was linking to what John Lear previously said about the specific claim that an non-pilot couldn't do it. That's it.

I'm not a pilot. There are pilots active in this thread. Direct your questions to them.

From what I've only recently come to understand, there are no more "heavy" commercial jet aircraft pilots who are able to participate and comment, either in this thread, the 9/11 forum, or ATS as a whole, although one would presume there might be some left, out of a membership exceeding 100,000 people.

As to John Lear..

Here is what John Lear had to say about the speeds, in an affidavit he filed, years ago, (Jan 28th, 2008) long before Pilots for 9/11 Truth produced "9/11: World Trade Center Attack" and before the release of the NTSB radar data report showing a 510 knot airspeed both during descent, and, after leveling off on it's final approach to impact, for the south tower plane.

"19. The alleged NIST speed of 443 mph (385 kts,) for American Airlines Flight 11 would be technically achievable. However the NIST speed of 542 mph (470 kts) for United Airlines Flight 175 which is 50 kts. above VD is not commensurate with and/or possible, considering:
(1) the power available,* **
(2) parasite drag (NAVAIR 00-80T-80 Aerodynamics for Naval Aviators
(3) parasite power (NAVAIR 00-80T-80 Aerodynamics for Naval Aviators
(4) the controllability by a pilot with limited experience. 14 CFR Part 25.253 (a)(B)
www.ntsb.gov...
www.content.airbusworld.com...
20. Therefore the speed of the aircraft, that hit the World Trade Center, as represented by NIST, particularly that of United Airlines Flight 175 is fraudulent and could not have occurred."

morganreynolds.files.wordpress.com...

And yes, he obviously changed his mind when he became aware of the impossible speed involved, and a "no plane theorist" when he examined the work of Morgan Reynolds regarding the nature of the impact, penetration of the building and near instantaneous destruction of the plane.

Based on the analysis I've offered here and some consideration as to the nature of certain causes and effects from causes, it would appear that John Lear fell victim, as did Morgan Reynolds, to "the honey pot" syndrome evidently anticipated in the planning of the op itself, in failing to recognize that a highly modified, military grade Boeing 767-like aircraft, might very well be able to reach such a speed near sea level, completely penetrate the building's steel cladding exterior, whole, and detonate in a fraction of a second, exclusively within the confines of the building, to create the observed gargantuan fireball pyrotechnic display before the horrified watching world, given that a whole array of cameras, from every angle and POV were by this time trained sqaurely on the WTC complex.

No NRPT (no real plane theory), no "video fakery", no "holograms" disguises missiles as planes, but REAL planes doing what would otherwise be in the realm of impossible (he got that part right).

Needless to say, he's not the very best source to cite as an expert if the aim is to try to make the reported speed, along with flight control and maneuvering at such speed, seem entirely in the realm of plausible, both in terms of aircraft performance and piloting "skill" level, for reasons that we still have yet to fully explore but which will be covered in greater detail, in summary, tomorrow.


additional info

The problem with John Lear

NewAgeMan

given the additional research and info now available, perhaps he might see it differently, particularly in light of all the video and photographic evidence that indeed a plane was there and did in fact impact the building as observed.

Also, what does he think, if there was no plane there, was the cause of this?

What we're doing in this thread is basically just playing the tape of causation and phenomenon backwards, and in the process proving, objectively, that the causal linkage of events between the plane impacts and building destruction according to the official story, is blatantly untrue and cannot be believed or accepted by any truly objective and rational observer with a scientific mindset.

And it's history, so all is fair in love and war.

People are going to look back on this event, in the future, and they will see, and know.

Because we ALL question it at some level or another, the OS, and given the way the "investigation" and the final 9/11 Commission Report, by Dr. Philip D. Zelikow, was compromised, by a whole list of evident conflicts of interest, and the way the NIST report began and ended with only one hypothesis - we can only be left questioning even until the end of 9/11's #ty history.. a tipping point of some kind but not by expectation, and something capable of blindsiding the "relevant political (elite) community" (Zelikow), but not in the form of a homegrown "conspiracy theorist" terrorist, but instead nothing but the true itself. Blowback, not in the form of violence but in the fact that they f'd up BIG TIME, whereby everybody knows that some conspiracies are true, no matter how big or small it makes no difference. The facts don't lie.

We are most certainly allowed to and ought to question this historical event and what everyone might have been misled to believe over a bad call simply because the alternative is "unimaginable" (Zelikow). After all - "the planes hit the buildings collapsed we were attacked!" Who's going to deny or question that fact? Not in the immediate aftermath they won't but 12+ years later.. looking at it more clearly and more objectively in the rear view mirror of near 20/20 historical hindsight?

You cannot fool all the people all the time, it's just not possible and the "conspiracy theorists" are not always wrong, as we've come to see on many of these issues, including pretexts to the waging of war.

The operation counts on these things, on our naivety our innocent uncomprehending cattle-like shock and awe horror. It really jerked our chain that's for sure. "Changed the world" and isn't that what they so wanted, given the way it was misused and abused, looking back now on it's history, including the two wars, TSA, DHS, domestic spying, and all that..?

Just look at what it has wrought?

It's a sham though, a terrible and barbaric HOAX of Hitlerian and Orwellian proportions, combined.


Don't fall for it.

Not for a moment.

And yes, it CAN be proven and in the final analysis, it's entirely self evident, as we'll soon see, if you haven't already..


Stay tuned...


Best Regards, and Happy Happy New Year!

NAM

January 3rd, 2014.

P.S. I am NOT Winston Smith, and this isn't "1984".

You cannot persuade me otherwise. I will not go there. I cannot.
I cannot believe, the unbelievable, but neither will I, or you, dearest reader, fall victim to "the honey pot".

I do not love "Big Brother".

I love people.

Sometimes that which hurts, instructs. Hopefully it does anyway, and we're always learning and learning from mistakes, surely that applies to the larger history as well.

Never forget.

And why should we - looking around at the state of affairs..?


It's definitely relevant, this issue, that's for sure.

And it isn't about to go away either any time soon.

reply to post by NewAgeMan

NewAgeMan
If anyone would like to help with this, please feel free.

The evidence suggest the passport was found here on Albany st. behind the Bankers Trust building.



The evidence comes from these two sources: This man Richard Wozniak who found the passport.

I was now standing in what seemed to be a war zone. There were scattered police and firefighters all around the streets. It seemed that I was one of only a handful of civilians so I had to pass myself off as a security agent as I was determined to stay and help. I was now outside the Bankers Trust (130 Liberty St.) building approximately 100 ft. or so away from the entrance of the main tower. I could hear objects hitting the ground around me so I decided to work my way around the back of the building and now I had learned what had happened.
I was standing in the middle of what were the remains of a passenger aircraft. There were seats and engine parts smashed through car windows everywhere. What seemed to be an engine was embedded into the sidewalk and body parts were strewn all over the street. Then I looked down to my feet and picked up a passport. It was a Saudi passport. It was green with Arabic writing and as I opened it and saw the man’s face inside it and I felt as if I were looking into the eyes of someone that may have been part of the terror that I was witnessing around me and I later learned that I was right as I passed it off to an FBI agent that was standing a block away on West side Hwy who immediately took it from me. He then instructed me to leave the area but before he could notice I ran back to the side of the Bankers Trust building determined to help find survivors that may have been hurt in the streets or in the cars. Then my life was changed forever.

www.christian-faith.com...


And the other source is this photo taken by Chris Sorensen. The sequence of photos suggest this photo was taken on Albany St.



archive.org.../n0/mode/2up

As far as downwind drift is concerned the passport was found well within the area it could have drifted.

reply to post by waypastvne


Thanks waypastvne,

i gave you a star.

Just out of curiosity, what does Vesey Street (the location as per all the news reports) look like as a pinpoint location relative to the North Tower, as a comparison?

You did offer to be of help.. and i don't get if i don't ask..

Regards,

NAM

reply to post by waypastvne


Well this is one of those moments in history that we are left in the end with what our gut tells us. Some see a passport as a piece of solidifying evidence but others just point out how ludicrous and preposterous it is that it one would have survived and two been found.

One of those events people will be discussing far into the future.

Me, I reserve the right to change my mind daily. Lol

Most people never realize we simulate this kind of thing all the time and we always have. Military plans and trains for everything. Computer games and simulations, models, what happens if we do this etc etc.

It is not just the CIA who can do documents and deep covers etc. Each service branch has specialized units who can do these things. These planes are gutted and flown by remote and even crashed. This is not new.

For me, most days i am a good old patriotic veteran who believes everything the government tells us about these events and others. But then there are those days where I reread a post or thread and say no way that happened like that. I find myself doing this with regards to several historical events. 9-11, jfk, moon landings.
So am I just fickle. I don't think so... I have come to realize that most of us can be this way. Why, because most of the time we don't question our programming. I am not programed you say, lol. Well if you live here in the states you are. We get it from the time we are born, tv, school, radio, newspaper and magazines. It is everywhere and we are just conditioned or yes programed. We are programed not to question but we are awakening.

Oh well this is skunk works right lol....

The Bot

reply to post by soulwaxer


Soulwaxer, have you ever heard of something called a "Rube-Goldberg Machine"? It is a machine that is overly complicated and precisely timed to complete some mundane job. Every "Truth" Movement version of events is precisely that. Such overly complicated scenarios that require the precise timing and calibration that allows for no screw ups, chance, or unforeseen events that could derail or expose the whole grand show. It is kinda like this :

with the exact same hilarious result in the end
Ad in the end of the machine fun that is pretty much what happens to the "Truth" Movement. They end up shooting themselves in the foot.

reply to post by dlbott





Two words you use that I'm in agreement with.....
Ludicrous and preposterous ......as far as the passport story goes.

reply to post by GenRadek

GenRadek
Boy it has been a while, a long while since I have posted on ATS, and here I come across a thread that I could have sworn I saw nearly word for word years ago by another member. But anyways, I guess it is just coincidence.....

Anyways, I recall a few instances where airliners broke the sound barrier in dives, and survived. Like these:
Airlners breaking sound barrier

General (5*+),

We'll now address all the points you've raised. As a point of reference, please see the V-G Diagrams at the end of this, my rebuttal to your objection, which includes and compares each one of those precedent examples of near Mach airspeeds (which took place at altitude) as they compare to the equivalent airspeed near sea level (equivalent aerodynamic pressures), of the South Tower Plane as it was recorded travelling, in controlled flight, with g-force maneuvering, at 510 knots groundspeed (515 knots CAS if the windspeed vector is included as a very light wind from the N/W).

GenRadek

China Airlines 006

China Airlines Flight 006 (possible)

www.rvs.uni-bielefeld.de...
(scroll down about 3/4 of the page to "Analysis" for the above quote)

With all due respect, I'm sorry to have to tell you this General, but nowhere does it say either in your own quote, or in the NTSB Report, that the aircraft reached or exceeded Mach 1.

National Transportation Safety Board: China Airlines Boeing 747-SP Accident Report

www.rvs.uni-bielefeld.de...

Points/Notes:

Boeing 747SP (China Air 006): The 747SP is a much faster airplane than the 767. The 747SP Mmo or max operating speed is .92 Mach.

It never once reached or exceeded Mach 1.0, as we can see in examining the NTSB Report itself, and only brushed up against, and possibly exceeding only very minimally and briefly, it's VMO/MMO max operating speed limit.

It's Vd or design dive speed limit is actually .98 Mach., which is still under an EAS, near sea level, in terms of AIRSPEED and accompanying aerodynamic pressures.., of slightly less than 425 knots, the equivalent airspeed, at 22,000 feet alt. of .99 Mach (see OP), due to the equivalent airspeed difference between 700 ft alt. and say at 30,000 feet where the air is a full 2/3rds thinner than it is near sea leve where there's literally more air for the plane to fly through.


On EAS, from the OP

EAS:

EAS is sea level airspeed. As a factoral expression of the equivalent dynamic pressures on an airframe at low vs. high altitude, because the air is so much thicker at sea level, there is an airspeed appropriately titled "Equivalent Airspeed" or EAS.
The air is thinner at higher altitudes so the aircraft will need to go faster to match the amount of air hitting the airframe at low altitudes, in thick air.

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.

*****

GenRadek

"Speeds exceeded the airframe's maximum mach number of 0.92."

Again, so there can be no misunderstanding here, that's it's MMO (Max operating Mach number, at lower altitude, VMO due to EAS as outlined in the OP) - not it's Md, or flight envelope, design structureal dive speed limit, at altitude, is .98 Mach.

Even in the article and quote you offered on China Air 006, it never once mentioned reaching or exceeding Mach 1.0, ever, not once.

You were sadly mistaken General, in your assumption. I have to presume that you were not intentionally misleading on purpose. Then again you did have full benefit of the doubt, initially.

China Air 006 - Structural Damage:

About ten feet of the port tailplane and five feet of the starboard, including large parts of the elevators, were ripped off by aerodynamic forces during the descent, and during the periods of high gee the inboard main landing gear was forced down which also resulted in several of the landing gear doors falling off. There was sundry other damage to the empennage area and the landing gear bays.

Although the 747 was severely damaged by the incident—including the wings being permanently bent upwards—it was repaired and returned to service.

NAM:

The so called "debunkers" (if true sceptics with a scientific mindset, they would surely also have the capacity to thoroughly question the nature of the OS in light of all events and phenomenon under observation) love to use this example, for some strange reason.

Unfortunately for them, and for the dear General, it supports the case put forward here and corroborated by numerous "heavy" commercial pilots and aeronautical engineers with Piliots for 9/11 Truth, and contrary to their belief and expectation according to all manner of a priori assumptions, it (China Air) presents still MORE evidence - which shows that such aircraft will lose control and suffer structural failure when it exceeds manufacturers flight envelope limitations, set and established according to first wind tunnel and then flight "flutter" testing. Even when barely exceeding, if at all, it's MMO or max operating Mach limit - China Air 006 suffered structural failure and loss of control.

In that case the reason for it's structural failures, were due as much to g-force, as to aerodynamic pressures, which is why you'll find it's marked where it is on the V-G Diagram at the end of this rebuttal.

In the case of China Air the reason for it's structural failures, were due as much to g-force, as to aerodynamic pressures - which is why you'll find it where it is on the V-G Diagram at the end of this rebuttal.

*****

GenRadek

Now I understand that at higher altitudes the Mach numbers go down and it wouldn't be the same as Mach 1 at sea level. However, it is not the speed, but the aerodynamic forces that tear up the aircraft correct?

NAM: Correct.

That's why it's all about airspeed and equivalent airspeed to realistically compare the aerodynamic pressures involved, including the difference in airspeed related dymamic pressures at low vs. high altitude, again as outlined in the OP and reiterated throughout this thread. Planes fly through air. It's not about raw speed, but airspeed.

However, in terms of equivalent aerodynamic pressures at lower altitude and thus in thicker air, it's important to note in relation to Mach # speed flight at higher altitudes, that the VMO/MMO or max operating speed for the Boeing 767 is 360 knots (nearer sea level) / .86 Mach (360CASKTS/.86M), at 23,000 feet alt.

See the following screenshot from the airspeed calculator

http://www.luizmonteiro.com/Altimetry.aspx#EquivalentAirspeed as posted on page 3

A "General" Rebutall - Cont'd ..


reply to post by GenRadek

GenRadek

China Air 006:

According to the NTSB reports it did approach Mach 1 during its drop.

Again, for the second time, that's false, and misleading.

This is directly from the NTSB Report

"Although the captain said that the airplane exceeded Vmo twice and also decelerated below 100 KIAS during the dive, all three crew members said that they did not hear the overspeed warning and that the stall warning stickshaker did not activate. Examination of the reliable recorded airspeed data points showed that the Vmo limitation was not exceeded during the descent. However, the recorder data does show airspeeds at or below 100 KIAS. The Safety Board cannot explain why the stall warning stickshaker did not activate, or if it did activate, why it was not felt or heard by the flightcrew."

www.rvs.uni-bielefeld.de...

No where does it say that the aircraft either reached or exceeded Mach 1 in the NTSB report.

National Transportation Safety Board
China Airlines Boeing 747-SP Accident Report
www.rvs.uni-bielefeld.de...

*****

GenRadek

An airliner with engines at full throttle in a dive can hit speeds of 510 knots for a short period of time. It has been done. A 707 broke the sound barrier in a dive.

No they can't, as we shall see in a minute.. and no, it did not do so, that is false/untrue.

GenRadek

I believe that would be going over its Vmo.

There's a difference between Vmo, max operating limit, and, Vd design dive speed limit, as discussed, but, sadly for you, as outlined in the NTSB report, it didn't even do that, or, at most, touched the Vmo limit. What it certainly did not do was hit Mach 1.0 nor reach it's Md of .98 Mach, at altitude.

And again, just to be clear, an equivalent airspeed (aerodynamic pressure) of 425 knots, is the equivalent airspeed, at 22,000 ft., of .99 Mach - which is a full 85-90 knots (with windspeed) LESS than "UA175" was recorded flying (in control and maneuvering while also pulling G's), as outlined in the NTSB Radar Data Impact Speed Study Report .


*****

GenRadek

Also, I would reccomend you read this little article from 2003 about Vmo and exceeding it:
Exceeding The "Never To Exceed" Speed

Again, please note the difference between Vmo/Mmo and Vd/Md.

from the Article

The question:
"If Mmo = M.82 (that's an airplane limit and cannot be intentionally exceeded) then how can the airplane go to Mmo+M.07 if the sidestick is held full forward and stabilize at between Mmo and Mmo+M.04? Is there more than one exceedance speed? I asked that question many times and never got an answer."
The manufacturer's response (abbreviated):

"Flying at Vmo/Mmo is not forbidden [and] is possible with sidestick in neutral and no forces applied on the stick.

"Flying at a speed higher than Vmo/Mmo means flying into the peripheral flight envelope; although it is not operationally authorized to fly deliberately outside the normal flight envelope, it is not unsafe (in isolation) and it may happen (strong head gust during descent at Vmo/Mmo, or engines commanded at full power in level flight and pilot momentarily not in monitor/control of the speed/trajectory). [In such cases] the high speed protection will be activated (threshold is Vmo/Mmo plus a margin less a phase advance) if the sidestick is left in neutral, the protection will command a nose-up load factor until the speed is back below Vmo/Mmo ... But if, for whatever reason, the pilot wants to hold a speed higher than Vmo/Mmo, he can by maintaining steady nose down sidestick order. He will be warned by the permanent and unusual forces to be applied to the sidestick (in addition to the oral overspeed warning); at max, for instance, it may be flying steadily at Vmo+16 knots with full nose down sidestick deflection.

"The high speed protection is tuned in a way that guarantees that any reasonable excursion into the peripheral flight envelope ... will contain the speed below VD/MD [VD is design diving speed. MD is maximum diving speed]. For instance ... in the case when the aircraft would perform a dive with a pitch attitude of minus fifteen degrees, go through Vmo/Mmo at this pitch attitude, with no pilot recovery action greater than 1.5g and occurring only after reaching the threshold of overspeed warning. This is also checked against the most severe gusts and windshears that would be encountered while flying at Vmo/Mmo."

Although discussing Vmo/Mmo and the possibility to exceed it, which includes control responses, even if/when the sidestick is held down (with implication for controlled flight and maneuvering at such speed), designed to contain the airspeed below Vd/Md, no mention was made as to whether and how far the Vd/Md limit (outer flight envelope) could be exceeded, which isn't by much, as seen in the case of all precedents (+ see upcoming comparative V-G Diagram for more info and comprehension). Aside from "UA 175", none were able to exceed the Vd limit by more than 5 knots with the exception of the DC-8, which reached Mach 1.01 for 16 seconds during a steady, controlled dive (not at a dissimilar angle to the south tower plane during it's dive), at an altitude of 45,000-30,000 feet.


*****

GenRadek

The plane was never flying a straight and level flight at 510 knots the whole time. It was coming out of a dive, engines at full, and leveled off right before impact.

If he had leveled off earlier, the plane would have slowed down a bit due to drag at that altitude.

From the NTSB Radar Data Report (presented in post 2, of this thread)

"During the descent from 12,000 feet to 6,000 feet, the aircraft groundspeed remained between 500 - 520 knots. As the aircraft made it's descent to 1000 feet, it accelerated (there goes Zaphod58's hypothesis about self propulsion at level flight on final approach) and impacted World Trade Center tower #2 at approximately 510 knots groundspeed.

Radar_Data_Impact_Speed_Study--AA11,_UA175 (pdf)

*****

GenRadek

Planes are built with some serious safety margins.

The "safey margin" is Vmo/Mmo, where the outermost threshold of the flight envelope beyond which structural failure become imminent, is Vd/Md which is established first by wind tunnel and then flight testing.

from earlier in the thread.. you didn't even bother to read.

NewAgeMan
To better understand "Margin Of Safety" with respect to real aviation...

www.abovetopsecret.com...

A "General" Rebuttal - Cont'd ..

reply to post by GenRadek

GenRadek
Unfortunately some still unassumingly come across this, and take it at face value for truth.

To the contrary General. That's the way that your information has been presented, but it's false and worse, misleading and designed it would seem to confuse the issue as presented in the OP and thread.

GenRadek

Again, a plane will not fall apart the second it passes its "Not safe" parameters.

I've never once tried to say that, but there isn't a lot of room in the flight envelope even beyond Vmo/Mmo, let alone Vd/Md - as we shall see in a minute when comparing the precedents, including China Air, with the South Tower Plane.


*****

Flight 175 was in a controlled gentle dive with throttles up as well as a little friend called gravity. It came out of the dive and seconds later plowed into the WTC.

It was traveling at its high speed recorded for only a few moments.

False. Should have done your homework General, and maybe taken the time to actually read the OP and comb the thread content..

NTSB Radar Data Impact Speed Study Report

I am not the one here who has in any way mislead people and the readership, or regurgitated the same old same old lame rebuttals from way back in the "good 'ol days".. China Air at Mach.. as the best example to rebut and refute this information.. rly? oh well it made for a good example to further demonstrate the very premise and argument put forward in the OP.

"There is a principal which serves as a bar against all information and proof against all arguments, and which cannot fail to keep a man in everlasting ignorance. That principal is called - contempt, prior to investigation.

~ Herbert Spencer, Scientist

*****

GenRadek

I posted an article from Aviation Weekly. I suggest you read it on what it says about going past a plane's Vmo, etc Going over the speed limit is not going to cause the plane to explode in midair or noseover and crash.

Flight 175 was beyond the envelope for only a few moments.

Your statement is false, and misleading, and in fact all your statements are false and misleading, as demonstrated.

from that ariticle..

The Airbus flight manual says maximum speeds are: Vmo = 350 knots, Mmo = M.82. [Vmo is the maximum airspeed at which an aircraft is certified to operate. Mmo is the maximum Mach number at which an aircraft has been certified to operate.] However, in the section on Flight Controls, in referring to 'High Speed Protection' when operating in 'Normal' Flight Control Law, the book says: To prevent overspeed, a positive (nose up) load factor is imposed when airspeed exceeds Vmo+6 knots or Mmo+M.01. When activated, a pitch up demand is introduced, and the autopilot disconnects. When the protection is active, pilot sidestick authority is reduced and cannot overpower the automatic pitch up.
If the sidestick is HELD to the forward stop, the airspeed may increase to as much as Vmo+30 knots or Mmo+M.07, but will stabilize between Vmo and Vmo+16 knots or Mmo+M.04.

When the sidestick is released, the airspeed returns to Vmo and the protection is deactivated.

www.aviationtoday.com...

reply to post by GenRadek

GenRadek
Boy it has been a while, a long while since I have posted on ATS, and here I come across a thread that I could have sworn I saw nearly word for word years ago by another member.

Anyways, I recall a few instances where airliners broke the sound barrier in dives, and survived. Like these:
Airlners breaking sound barrier

A "General" Rebuttal - Conclusion.


See the following data which corroborates the things outlined in the OP and in the preceding rebuttal to your objections and it would seem, misdirections or misrepresentations of the facts before us as they really are.

V-G Graphs

China Air 006
Boeing 747SP

TWA Flight 841
Boeing 727

EA990
Boeing 767-366ER

Douglas DC-8 Test Flight (modified)


"Flight 77"

"Flight 175"



in the following graph, China Air 006, Boeing 747SP, was originally misplaced, (see top "747SP" @ Vd + 5 knots) which was done to try to appease the debunkers who were absolutely insistent and adamant, that it hit Mach 1 or came very close - ie: .99 Mach is the equivalent airspeed of 425 knots near sea level. However, after additional research and investigation or "homework" that was discovered to be inaccurate (see NTSB Accident Report).




This is how the 747SP should rightly be placed on the V-G Diagram, where although "only" @ Vmo/Mmo, nevertheless, because of the additional G-forces experienced during the uncontrolled descent and rollover, still suffered structural failures when that far out of the flight envelope which, as per the graph, is the outer structural limit of the aircraft as certified by flight testing aka flutter testing.



Addtional Note re: Vne and Vd

Vne has not been used on Jets since the 1960's.

"NASA VGH (velocity, load factor and altitude) recorders were installed on 12 types of turboprop and turbojet aircraft during the period 1960-61. Analysis of these data showed that the operation speeds Vno were being exceeded significantly more frequently than had been experienced in operations of piston-engined transports.

Because of the structural implications of these studies, the regulatory agencies and industry dropped the use of Vne for commercial transports certified under FAR 25. In 1964 the maximum operating limit speed Vmo was introduced in FAR 25.1505; i.e., “Vmo Speeds; The maximum operating limit speed (Vmo/Mmo airpseed or Mach number, whichever is critical at that particular altitude) is a speed that may not be deliberately exceeded in any regime of flight (climb, cruise, or descent), unless a higher speed is authorized for flight test or pilot training."
books.google.ca...=onepage&q&f=false

Basically, Vno was replaced with Vmo, and Vne was replaced with Vd on Jets.

Small/slower aircraft still use Vno/Vne because you wont exceed those limits as fast as you would in a Jet.

Small Aircraft VNE

A single-engine Cessna 150L's airspeed indicator indicating its V speeds.

V Speeds
en.wikipedia.org...

They created Vmo for Jets so they keep pilots away from Vne/Vd limit.. .also known as the flutter limit as you have seen in the Airbus380 video including in the OP.

again, there is no difference between Vne and Vd. They are the same.

Vne/Vd is the end of the flight envelope and the start of the structural failure zone for every airplane on this planet.

"The dive speed is the absolute maximum speed above which the aircraft must not fly [ie. NEVER EXCEED]. Typically, to achieve this speed, the aircraft must enter a dive (steep descent), as the engines cannot produce sufficient thrust to overcome aerodynamic drag in level flight. At the dive speed, excessive aircraft vibrations develop which put the aircraft structural integrity at stake."

Source - theflyingengineer.com...

Boeing 767-200 (300..)
Vmo/Mmo: 360kts/.86M

Vd/Md: 420kts/.91m

Boeing 767 A1NM Type Certificate Data Sheet

V-G Diagram Explained


...nothing to see here folks, please move along...

...nothing to see here folks, please move along...


*****

GenRadek

in the end of the machine fun that is pretty much what happens to the "Truth" Movement. They end up shooting themselves in the foot.

GenRadek

those old "Truth" websites, *snicker*, but it is enjoyable watching them shoot themselves in the foot.

A little overly confident and presumptuous maybe, General?


Regards (please forgive me if i just can't quite bring myself to offer you a sharp and respectful salute),

NAM
January 5th, 2014